FINAL EXAM Y12 Flashcards

Question

Define infectious disease

Answer 1

Infectious diseases: Diseases caused by foreign organisms invading the body and multiplying there

Answer 2

Pathogen: A disease causing organism often referred to as a pathogenic organism

Answer 3

Vectors: An agent such as an insect capable of transferring a disease causing organism from one person to another

Answer 4

bacterial and viruses ( also fungi and animal parasites)

Answer 5

Physical characteristics of bacteria: single celled, seen only with a microscope, cell shape is used to classify into 4 catergories : cocci ( circular), bacilli ( rods), spirilla (loose coils) and vibrio ( curved rods)

Answer 6

Mode of action for bacteria: releasing toxins which inhibit/ alter cell activity or poisons which alter metabolism, they may also cause allergic reactions. Endotoxins- released when bacteria die, exotoxins- released by living bacteria. Bacterial antigen- allergic/ immune response

Answer 7

``` Diseases caused by bacteria: Chlamydia Cholera Gonnorrhoea Dental caries (tooth decay) Leprosy Pneumonia ```

Answer 8

viruses | Physical characteristics: molecules of DNA or RNA, small, wrapped in proteins.

Answer 9

Mode of action: DNA or DNA induce cell to manufacture more virus particles, attaching to the outside of a host cell allowing the nucleic acid to enter the cell, new viral genes are then produced by the host.

Answer 10

``` Diseases caused by viruses: HIV/AIDS, Bird flu Chickenpox Herpes Colds Ebola ```

Answer 11

Direct: Transmission by touch: direct and fomite(indirect) Transmission by bodily fluids: through blood or other mucus membranes ( from nose, mouth, throat, genitals) eg. HIV, hepatitis b & c Waterborne transmission: from drinking contaminated water or from droplets of moisture w/ pathogenic organisms are emitted when breathing, talking, sneezing or coughing eg. Influenza Airborne transmission:moisture in exhaled droplets carry viruses and some bacteria Ingestion: food or drink contaminated eg. Salmonella Transmission of vectors: transfer of pathogens by other animals such as insects, ticks or mites. Some transfer directly others ( house flys) via food and water. Forms of transmission by contact: direct( Touching an Infected person) or indirect (touching an object that has been touched by an infected individual, also known as fomite transmission ) Disease specific vectors- malaria> mosquitos

Answer 12

Bacteriophage:Viruses which multiply in bacterial cells causing death to the bacterium

Answer 13

parasites Diseases: Malaria, roundworms, lice Physical characteristics:Multicellular, ecto and endo Mode of action:Parasites cause infection by living and multiplying in another organism. This can cause fever, inflammation and other physical problems

Answer 14

fungi Diseases: ringworm Physical characteristics: Multicellular, Eukaryotic Mode of action: Reproduce by spreading microscopic spores, spores often found in air and soil where they can be inhaled or come in contact with body surfaces

Answer 15

Prions Diseases: Mad cow disease Physical characteristics: Folded protein structure Mode of action: Prions are a type of protein that can trigger normal proteins in the brain to fold abnormally

Answer 16

Protozoa Physical characteristics:Moves independently, single cellular Modes of action: Produce toxin and multiply inside other cells Disease: malaria

Answer 17

First of defence: external barriers physical + chemical barriers/ protective reflexes -> prevent entry into the body Second line of defence: non specific internal defences inflammation, fever, roaming macrophages-> destroy and remove pathogens if enter. Third line of defence: specific internal defences - antibody and cell mediated defences-> specialised lymphocytes target specific pathogens to destroy and remove from the body.

Answer 18

skin: covers the outside of the body, stopping entry of microorganisms Bacteria - huge number of bacteria live on the skin at a time???? Sebum- oily secretion secreted by the oil grands in the skin that kills some pathogenic bacteria. Sweat- secreted onto skin and contains salts and fatty acids that prevent the growth of many microorganisms. Mucus membranes- line body cavities that open to the exterior. They secrete mucus, which inhibits the entry of microorganisms to the organs of the body. The whole digestive, urinary and reproductive tracts are protected in this way. Also in ears. Cilia- hair like projections that like tranche and brochi, that beat, moving mucus and trapping particles and microorganisms towards the throat where it may be coughed up or swallowed. Acids- in stomach kill bacteria taken in with food or contained in mucus swallowed from the nose and windpipe, the vagina also has acid secretions that reduce growth of microorganisms. The sweat on the skin is also slightly acidic. Lysozyme: enzyme that kill bacteria, found in tears, saliva, sweat, secretions of nose and tissue fluid, Cerumen- earwax. Protects ear against bacteria as is slightly acidic and contains lysozyme enzymes. Flushing of body fluids keeps areas relatively free of pathogens. Eg, Urine flow through urethra. Hairs- found in nodal cavity and ears protect again invading microorganisms + protective reflexes

Answer 19

Protective reflexes: Automatic, involuntary response to a stimulus that help to protect the body from injury or from infection

Answer 20

Sneezing-Dust particles and noxious fumes which are likely to carrying microorganisms cause irritation. Stimulus is irritation of the walls of the nasal cavity, response is a forceful expulsion of air from the lungs which carry mucus, foreign particles and irritating gases through the nose and mouth Coughing- Stimulus for coughing is irritation of respiratory tract (bronchi and bronchioles) resulting in air being forced from lungs to remove irritant. - air drives mucus and foreign matter up the trachea towards the throat and mouth. Vomiting- Vomiting has a psychological stimuli. Excessive stretching of the stomach and bacterial toxins can induce vomiting, Which is the contraction of muscles of the abdomen and diaphragm in order to expel the stomach contents. Diarrhoea-Irritation of small and large intestines by bacteria, viruses or Protozoans can cause diarrhoea. The irritation causes increased concentrations of the muscles of the walls of the intestines so that the irritant can be removed as quickly as possible. -Diarrhoea happens when material does not stay in large intestines long enough for water to be absorbed to the faeces are very watery

Answer 21

Phagocytes- cells that are able to engulf microorganisms and cell debris

Answer 22

Phagocytosis: ‘ cellular eating’

Answer 23

Leucocytes- a white blood cell

Answer 24

Macrophages- a phagocytise cell derived from a monocyte (type of white blood cell)

Answer 25

Inflammation- the response to damage to a tissue; involves swelling, heat, pain and redness in the affected area.

Answer 26

Purpose of inflammation: > reduce spread of any pathogen, to destroy the, and to prevent the entry of additional pathogens > remove damaged tissue and cell debris > begin repair of the damaged tissue

Answer 27

Inflammatory response 1. Damaged mast cells in connective tissue cause release of histamine and heparin 2. Histamine increases blood flow to site of injury. Vessel becomes leaky, bringing necessary components to site. 3. heparin prevents blood clot to immediate area. (Clot forms around actual damaged vessels to prevent spread of infection) 4. Mast cells initiate release chemicals which attract phagocytes (chemotaxis) causing phagocytosis of debris and invading pathogens 5. Abnormal conditions in the tissue stimulate pain receptors, and so the person feels pain in the inflamed area 6. Phagocytes filled with bacteria and debris-> die and become pus 7. Mitosis-> produces new cells and repair damaged tissue

Answer 28

Pyrexia- body temperature above the normal range (37°c) with no known cause ( exercise/ menstural cycle not regarded as fever)

Answer 29

Hypothalamus ( above pituitary gland)- controls body temperature thermostat set at 37°. If cold-> goosebumps, conscious changes, vasoconstriction, shivering If hot-> sweat, vasodilation

Answer 30

1. Pathogens enter body or cancer cells, autoimmune disease, heatstroke develop or medications cause response 2. Pathogens are destroyed by leukocytes which then send a chemical message to the hypothalamus 3. Thermostat is reset higher, body activity heats up to reach new temp initially person feels cold ( shivering and vasoconstriction) when body reaches temp person feels hot ( sweating and vasodilation) 4. If pathogen removed thermostat resets to normal 37° and body cools down 5. Of pathogen not removed, thermostat resets higher and process repeats itself #dangerous if too hot around 41°-> body tissue/ enzymes start to denature - convulsions (fit) + organ failure #

Answer 31

Increasing body temperature: Denatures and inactivates pathogens Increases leukocyte activity so faster destruction and phagocytosis of pathogens Increases rates of repair of damaged tissues#

Answer 32

Antibiotics: a chemical able to inhibit the growth of, or kill, microorganisms, particularly bacteria What type of pathogen: they fight infections of microorganisms, particularly bacteria (sometimes fungi)

Answer 33

bactericidal antibiotics- kill bacteria by changing the structure of the cell wall or cell membrane ( cell wall synthesis) by disrupting the action of essential enzymes, Bacteriostatic antibiotics - rather than killing they stop bacteria from reproducing and inhibit growth, usually ( altering shape of ribosomes/ tRNA) by disrupting protein synthesis, preventing metabolic processes ( ie. cell respiration, altering nucleic acid/ preventing respiration

Answer 34

Antivirals: a drug user for the treatment of viral infections What type of pathogens?: viral infections

Answer 35

Mode of action: Inhibit the development of viruses (inactivates) viral proteins are disabled by specifically designed chemical. They prevent viruses from entering cell, synthesis of virus genome, prevent synthesis of viral proteins and prevent release of virus. Examples: Acyclovir- herpes infections Interferons- hepatitis B How are they made? ...

Answer 36

1. Collect fluid lost by capillaries and returns it to the bloodstream 2. Absorb fatty acids and glycerol in the small intestines 3. Contains leukocytes which destroy and remove pathogens

Answer 37

- numerous in neck, armpit and groin - bean shaped - 1-25 mm diameters - encapsulated in connective tissue contain macrophages

Answer 38

- large phagocytes - roam in lymph targeting foreign bodies (non cell antigens) phagocytosis takes pathogen into the cell and digests

Answer 39

Guard against SPECIFIC types of antigens by initiating a response by specific leukocytes. B and T lymphocytes are programmed to recognise antigens on pathogens and are activated to initiate an immune response

Answer 40

Bcells : originate and mature in bone marrow Tcells: orgininate in bone marrow and mature in thymus gland

Answer 41

B: chemical -> produce antibodies T: cellular-> types of T cells with various roles

Answer 42

B plasma cell- produce antibodies | B memory cell

Answer 43

Extra cellular bacteria/ virus | Try to remove before cell in affected

Answer 44

Intracellular phase of infections to destroy affected cell , cancer, foreign tissues ( eg. Transplants) and larger particles

Answer 45

B: relatively short lived ( b plasma cells) T: relatively long lived

Answer 46

There are receptors on the B cells

Answer 47

Growth and proliferation (cloning)

Answer 48

Immunoglobulins

Answer 49

- they inactivate the pathogen - immobilise - dissolve pathogen - agglutination ( cause antigens to clump together) - coat pathogen-> attract phagocytes neutralise bacterial toxins or viruses by coating them and preventing them entering cells

Answer 50

T cells- Lymphocytes that mature in the thymus gland containing receptors for specific antigens. They work against intracellular phase of infection to destroy affected cells, cancer cells and foreign tissue transplants.

Answer 51

Macrophages, B cells, helper T cells etc. come in contact with a specific T cell which is activated and then divides

Answer 52

Cytotoxic T cells, helper T cells, suppressor T cells and memory T cells

Answer 53

Cytotoxic T cells- Killer T cells that secrete a chemical which dissolves the pathogen or cause it to burst (lose)

Answer 54

The primary response is the response to the initial exposure to the antigen. It takes more time for antibodies to be developed because of this and there symptoms are worse. The secondary response is the response to the second or any subsequent responses after the initial. It takes less time for antibodies to develop as the body already contains memory cells. Because of this the symptoms are often less severe or they are no symptoms

Answer 55

Natural passive: immediate, temporary immunity with no human intervention. When pathogens are passed from 1 person to another ( mother to foetus across placenta and amniotic fluid) Natural active: takes time and is prolonged immunity with nohuman intervention. When Natural exposure to antigens occurs. ( chicken pox, flu virus) Artificial passive:immediate, temporary immunity with human intervention. When antibodies are injected into the blood stream. ( serious illness where immediate action is required eg, tetanus, diphtheria or if someone has a poor immune system ) Artificial active:takes time and is prolonged immunity with human intervention. Occurs when antigen injected into the body initiates an immune response to produce antibodies. ( vaccines, eg. Measles, mumps) it is preventative

Answer 56

Programming the immune system so that the body can respond rapidly to infecting microorganisms Reasons for immunisation: all tested rigorously by by law in AUS herd immunity Objections to immunisation: some contain chemicals that are poisons such as mercury ( as a preservative) May contain allergens Religious objections

Answer 57

Vaccination: The introducing of antigens to a person so that they Aquire immunity without suffering from the illness Vaccine: An antigen preparation used in immunisation

Answer 58

- living attenuated microorganisms eg. Measles, mumps and rubella ( reduce ability to produce disease symptoms) - dead microorganisms eg. Cholera, bubonic plague ( immunity not as prolonged as first type) - toxoids eg. Diphtheria, tetanus. ( made from filaments of bacterial cultures containing toxins- toxins are inactivated) subunit eg. Human papilloma virus, hepatitis b. ( fragment of organism is used to provoke immune response )

Answer 59

Herd immunity: Type of group immunity that occurs when a high proportion of people in a population are immunised that those who are not immunised are protected

Answer 60

Alzheimer’s: form of dementia causing problems with memory thinking and behaviour Cause: People with Alzheimer’s disease have abnormal clumps (amyloid plaques) & tangled bundles of fibres (tau tangles) in the brain. Symptoms Effect: Alzheimer’s disease is characterised by progressive & irreversible mental deterioration. It gradually destroys memory & thinking skills, eventually leading to confusion, mood swings, aggression & general withdrawal. Treatment: Treatment Drugs are available to manage the symptoms of the illness & slow its progress. Drugs aim at increasing acetylcholine levels, as acetylcholine is a neurotransmitter essential for processing memory & learning.

Answer 61

Cause: Destruction of dopamine-producing cells in the basal nuclei of the cerebrum. Symptoms: Slowed physical & mental responses, muscular tremors, stiffness of the limbs, impaired balance & coordination. Treatment: A variety of medications which either contain or act like dopamine, block acetylcholine or prevent the breakdown of dopamine.

Answer 62

Exocrine and endocrine Endocrine glands: Glands that secrete hormones isn’t extracellular fluid that surrounds the cells that make up the gland. The secretion usually passes into the capillaries to be transported by the blood. Endocrine glands are ductless. Exocrine glands: Glands that secrete hormones into a duct that carries the secretion to the body surface of to one of the body cavities

Answer 63

``` Exocrine gland examples Sweat glands Salivary glands Sebaceous glands Glands of the alimentary canal ``` ``` 9 major endocrine glands Pineal Hypothalamus Pituitary Thyroid Parathyroid Thymus Adrenal Pancreas Gonads ```

Answer 64

``` Endocrine hormones of pituitary gland Follicle stimulating hormone Luteinising hormone Growth hormone Thyroid stimulating hormone Adrenocorticotropic hormones? Prolactin Antidiuretic hormone Oxytocin ```

Answer 65

Oxytocin and antidiuretic hormone

Answer 66

Thyroxine which targets most body cells to increase metabolic rate and thence oxygen consumption and heat production

Answer 67

Parathyroid hormone which targets the bones and kidneys to increase rate of osteoclast activity, increasing levels of calcium in blood and control phosphate levels

Answer 68

The gonads where it stimulates growth of follicles and the production of spermatogonia

Answer 69

- Ovaries in females where it is involved in ovulation and maintainance of corpus luteum. - leydig cells in the testes of males where it stimulates secretion of testosterone

Answer 70

Growth hormone target | All cells, stimulating growth and protein synthesis

Answer 71

TSH target | Thyroid stimulating production of hormones of thyroid gland

Answer 72

Adrenocorticotropic hormone | The adrenal cortex where it stimulates secretion of hormones from the adrenal cortex

Answer 73

Prolactin hormone target | The mammary glands where it stimulates production of milk

Answer 74

``` ADH target The kidneys ( specifically the distal proximal tubule and collecting duct of nephrons) where it causes reabsorption of water ```

Answer 75

Oxytocin target The uterus where it allows contractions during childbirth and The mammary glands which allow the release of milk

Answer 76

It is released by the thymus and targets t lymphocytes to stimulate development and maturation of T lymphocytes

Answer 77

Released by the adrenal cortex to target the kidney/ nephron ( WHERE SPECIFICALLY) where it increases reabsorbtion of sodium ions and secretion of water and potassium ions

Answer 78

Hormones released by adrenal cortex | Aldosterone and cortisol

Answer 79

Where is cortisol released and what is its effect? The adrenal cortex to target most cells where it promotes normal metabolism; helps the body deal with stress and promotes repair of damaged tissues

Answer 80

Adrenaline and noradrenaline

Answer 81

Produced by the adrenal medulla and targets most tissues where it prepares the body for fight or flight response ; reinforcing the effects of the sympathetic nervous system

Answer 82

The pancreas to target most cells where it stimulates uptake of glucose; lowers blood glucose level

Answer 83

Released by the pancreas and targets the liver and fat storage tissues to stimulate breakdown of Glycogen and fat; increase blood glucose levels

Answer 84

In the testes where it targets many tissues to stimulate sperm production, growth of skeleton and muscles; male sexual characteristics

Answer 85

Released by the ovaries, targeting many tissues to stimulate development of female secondary sexual characteristics and regulate menstrual cycle and development of endometrium

Answer 86

Released via the ovaries to target ..the uterus where it regulates menstrual cycle and pregnancy and maintains endometrium ..the mammary glands where it prepares the mammary glands for milk secretion

Answer 87

Produced by the thyroid to target bones kidneys and intestines where it is involved in calcium regulation

Answer 88

Proteins and amines are water soluble so they can’t enter, instead Hormone attaches to protein specific receptor in the membrane of the target cell. The combo of hormone with the receptor causes a secondary messenger substance to diffuse through the cell and activate Particular enzyme.

Answer 89

Steroid hormones are lipid soluable so they enter the target cell and combine to a receptor protein inside the cell. The receptor may be mitochondria, on other organelles of in the nucleus. The hormone receptor complex activates the genes controlling formation of particular proteins

Answer 90

Steroids can because Cell membrane is made of a phospholipid bylayer. Steroid hormones are lipid soluable so they enter the target cell and combine to a receptor protein inside the cell. Protiens and amines can’t.Proteins and amines are water soluble so they can’t enter, instead Hormone attaches to protein specific receptor in the membrane of the target cell

Answer 91

Anterior lobe - releases and produces hormones. hormone secretions are controlled by regulating factors. Hormones are secreted into EF surrounding the cells of hypothalamus and carried by blood to Anterior lobe. Posterior lobe- doesn’t produce hormones but releases them. Joined to hypothalamus by the nerve fibres that come from nerve cell bodies in hypothalamus and pass through the infundibulum to the posterior lobe.

Answer 92

Lipid soluble hormones- cortisol, aldosterone | Water soluble hormones- FSH, insulin,

Answer 93

Posterior lobe- + not a true gland as doesn’t produce hormones. hormones are produced by neurosecretory neurons +produced in the soma, travel down axon and are stored in the axon terminals in the posterior lobe. + nerve impulse triggers the release of hormones from axon terminals in the posterior lobe where they are stored until a nerve impulse initiates release and hormones are releases into bloodstream. (Antidiuretic hormone and oxytocin)

Answer 94

+Hypothalamus produces releasing and inhibiting factors in neurosecretory neurons. +factor is secreted into hypophyseal portal system and bloodstream carries factors directly into the anterior lobe + factors reach target endocrine cells (with corresponding receptors) and initiate a response: Releasing factor would increase production/ release of hormone. Inhibiting factor would decrease production/ release of hormone. (Eg, growth hormone inhibiting and releasing factor) hormones released travel through extracellular fluid and into the bloodstream, travelling around it until it reaches its target cells.

Answer 95

Infundibulum is the sack like structure that joins the pituitary gland to the hypothalamus

Answer 96

is the sum total of all the body’s reactions when at rest. It is the measure of the amount of energy the body uses when at rest.

Answer 97

Essential for nerve impulse contraction and bone strength. It is controlled by calcitonin, vitamin D and parathormone

Answer 98

Stimulus: low blood calcium levels Receptor: chemoreceptors in parathyroid gland Modulator: parathyroid gland which releases parathormone Effector:bones, kidneys, intestines Response: bones- osteoclast break down bone for calcium kidneys- reabsorption of calcium Intestines- absorption of calcium increase Feedback: increased calcium in bloodstream (negative)

Answer 99

Stimulus: high blood calcium levels Receptor: chemoreceptors in parathyroid gland Modulator: thyroid which releases calcitonin Effector:bones, kidneys, intestines Response: bones- osteoblasts build up bone for calcium kidneys- decreased reabsorption of calcium Intestines- decreased absorption of calcium increase Feedback: decreased calcium in bloodstream ( negative)

Answer 100

Stimulus: high levels of thyroxine in blood Receptor: chemoreceptors in hypothalamus Modulator: hypothalamus produces thyroid stimulating hormone inhibiting factor which stimulates the anterior lobe of PG to decrease TSH production and release. Effector: thyroid gland Response:thyroid produceses less thyroxine Feedback, decreased levelsof thyroxine in bloodstream ( negative)

Answer 101

Stimulus: low levels of thyroxine in blood Receptor: chemoreceptors in hypothalamus Modulator: hypothalamus produces thyroid stimulating hormone inhibiting factor which stimulates the anterior lobe of PG to decrease TSH production and release. Effector: thyroid gland Response:thyroid produceses less thyroxine Feedback, decreased levelsof thyroxine in bloodstream

Answer 102

Stimulus: increased metabolism/ body temperature Receptor: thermoreceptors in the skin and hypothalamus as well as chemoreceptors in hypothalamus detect thyroxine levels Modulator: hypothalamus releases thyroid stimulating hormone inhibiting factor which decreases TSH production in Anterior lobe of pituitary gland affecting the thyroid gland to produce less thyroxine Effector: somatic cells Response: decreased metabolism causes decreased protein synthesis and cell respiration Feedback: reduced metabolism and reduced body temperature (negative)

Answer 103

Stimulus: decreased metabolism/ body temperature Receptor: thermoreceptors in the skin and hypothalamus as well as chemoreceptors in hypothalamus detect thyroxine levels Modulator: hypothalamus releases thyroid stimulating hormone releasing factor which increases TSH production in Anterior lobe of pituitary gland affecting the thyroid gland to produce more thyroxine Effector: somatic cells Response: increased metabolism causes increased protein synthesis and cell respiration Feedback: increased metabolism and increased body temperature (negatiVe)

Answer 104

Hyperthyroidism: Overproduction of thyroxine Eg. Graves’ disease: most common type Cause: caused by an immune system reaction and there seems to be genetic predisposition for the condition Effect: increased rate of metabolism, nervousness, anxiety, weight loss, rapid heart rate, hand tremors, sleeping problems, excessive sweating, feeling hot. Treatment: - drugs that blocks thyroid glands use of iodine - surgery to remove some of or all of gland - drink containing radioactive iodine molecules which are taken up by thyroid cells wh

Answer 105

Hypothyroidism: underproduction of thyroxine Eg. Hashimotos: deficiency caused by attack on the thyroid gland by patients immune system Cause: problems which thyroid gland or pituitary gland or hypothalamus, lack or iodine in diet, surgery removing gland Effect: weakness, fatigue, weight gain or difficultly regulating weight, intolerance to cold, muscle cramps, depression slowing of mental capabilities, rough or dry skin, deepening voice, memory loss, swollen younger and face, goitre Treatment: inclusion of extra iodine in diet thyroxine tablets no cure and hormone tablets must be taken for rest of life

Answer 106

Stimulus: high levels of thyroxine in blood Receptor: chemoreceptors in hypothalamus Modulator: hypothalamus produces TSHIF cause my decreased production and release of TSH in pituitary gland Effector: autoimmune response leads to increase in size of thyroid Response: thyroid continues to produce thyroxine despite no TSH available Feedback: thyroxine remains high in blood ( positive)

Answer 107

Stimulus: low levels of thyroxine Receptor: chemoreceptors in hypothalamus detect Modulator: hypothalamus releases TSHRF to pituitary gland causing increase TSH Effector: thyroid gland is for whatever reason not able to respond Response: no thyroxine produced Feedback: low levels of thyroxine (positive)

Answer 108

Thermoregulation: The regulation of body temperature, the balance of heat gain and heat loss in order to maintain a constant internal body temperature independent of environmental temperature

Answer 109

If body temperature is too hot: - Vasodilation: radiation and convection - Sweating: evaporation allows increased heat loss - long term they can be an decrease in metabolic rate= heat loss - behavioural response If body temperature is too cold vasoconstriction decreases blood flow to skin adrenal medulla stimulated to secret adrenaline and noradrenaline shivering increases friction and cell respiration increased thyroxine production/ metabolism behavioural response

Answer 110

S: Low temperature R: thermoreceptor in skin and hypothalamus M: heat production centre of thermoregulatory center of hypothalamus E: cerebral cortex R: conscious changes F: increased body temp

Answer 111

S: Low temperature R: thermoreceptor in skin and hypothalamus M: heat production centre of thermoregulatory center of hypothalamus sends nerve impulse to cerebral cortex E: primary motor area in frontal lobe R: rhythmic contracting and relaxing causing increased cell respiration and friction F: increased body temp

Answer 112

S: Low temperature R: thermoreceptor in skin and hypothalamus M: heat production centre of thermoregulatory center of hypothalamus sends nerve impulse to medulla which sends message to... E: skin blood vessels R: prevents blood going to skin= less heat lost F: increased body temp

Answer 113

S: Low temperature R: thermoreceptor in skin and hypothalamus M: heat production centre of thermoregulatory center of hypothalamus E: somatic cells R: more thyroxine production increased respiration F: increased body temp

Answer 114

S: Low temperature R: thermoreceptor in skin and hypothalamus M: heat production centre of thermoregulatory center of hypothalamus sends nerve impulse to medulla olongata via Autonomic nervous system sympathetic route. E: adrenal medulla R: release noradrenaline to increase cell respiration and heat production F: increased body temp

Answer 115

S: high temperature R: heat thermoreceptor in skin and hypothalamus M: heat production centre of thermoregulatory center of hypothalamus E: cerebral cortex R: conscious changes F: decreased body temp

Answer 116

S: high temperature R: thermoreceptor in skin and hypothalamus M: heat production centre of thermoregulatory centre of hypothalamus sends nerve impulse via Autonomic nervous system E: sweat glands R: produce and release sweat which then evaporates F: decreased body temp

Answer 117

S: high temperature R: thermoreceptor in skin and hypothalamus M: heat production centre of thermoregulatory centre of hypothalamus sends nerve impulse to medulla which sends Autonomic impulse to vessels E: smooth muscles in arterialise going to skin R: blood vessels vasodilation increasing blood flow to skin allowing radiation and convection F: decreased body temp

Answer 118

S: high temperature R: thermoreceptor in skin and hypothalamus M: heat production centre of thermoregulatory center of hypothalamus E: somatic cells R: decreased metabolism= less heat production F: decreased body temp

Answer 119

Heat transfer: Balancing the loss and gain of heat through transferring it.

Answer 120

``` Types of heat transfer: Conduction Convection Radiation Evaporation ```

Answer 121

Conduction: -When heat energy moves FROM A WARMER OBJECT TO A COOLER OBJECT when they are in DIRECT PHYSICAL CONTACT - if you touch a cold object passes from your body to the object and reverse happens when you touch something hotter than ur body Convention: - An object will HEAT OR COOL AIR as it passes over the object the CURRENTS OV MOVING AIR REMOVE HEAT ENERGY from the object Radiation: - heat energy moves FROM A WARMER OBJECT ACROSS A SPACE - no contact necessary - if your body has higher temp than the environment you will radiate heat into environment which cools the body and visevera Evaporation:- LIQUID water is CONVERTED to WATER VAPOR - REQUIRES ENERGY (in the form of heat) which is taken from body-> body cools as we sweat the evaporation of sweat from the skin cools the body

Answer 122

How is heat produced? Carbohydrates, proteins and lipids we eat contain energy and in the process of cellular respiration food is oxidized in cells and energy released. Whilst some energy is used for cellular and body activity, most is released in form of heat

Answer 123

Metabolic rate: Rate at which energy is released by the breakdown of food. Exercise, stress and body temperature all affect this

Answer 124

Types of thermoreceptors: Peripheral and centeral Central- hypothalamus Peripheral- skin and some mucous membrane Types of peripheral thermoreceptors? Cold and heat receptors # temperature above Above 45° is lethal #

Answer 125

Heatstroke: When body temperature continues to rise and regulatory Mechanisms cease and body cannot lose heat by radiation or evaporation( often due to humidity and high body temp) Cured by quickly cooling body in cold water

Answer 126

Heat exhaustion: Loss of water reduces volume of blood plasma lowering blood pressure and output causing person to maybe collapse. Often occurs as a result of extreme sweating and vasodilation

Answer 127

37° is optimum for cellular respiration #

Answer 128

High blood sugar= can lead to diabetes

Answer 129

Caused by not enough insulin to manage glucose levels or; when insulin is not effective enough because your body is ‘insensitive’ to insulin

Answer 130

Increase glucose levels

Answer 131

Secreted by beta cells in islets of langerhan in pancreas gland

Answer 132

Alpha cells In islets of langerhan in the pancreas

Answer 133

S= low blood glucose levels R= pancreas has islets of langerhan alpha cells have chemoreceptors on them M= alpha cells in pancreas secrete glucagon E= liver, adipose tissue, cells R= gluconeogenesis, lypolysis, glycogenlysis F= increased blood glucose (Negative feedback loop)

Answer 134

Lypogenesis: Metabolic formation of fat -Happens to adipose tissue (Decreases BG levels)

Answer 135

Making glucose from protein -Happens to all cells (Decreases BG levels)

Answer 136

Breakdown of fats and other lipids by hydrolysis to release fatty acids which converts into glucose - adipose tissue (Increases BG levels)

Answer 137

Movement of glucose from blood stream into cells | Happens at all cells (Decreases BG levels)

Answer 138

Stimulated by the release of insulin and acts to reduce blood glucose levels -Happens at all cells (Decreases BG levels)

Answer 139

Glycogenolysis: Process of converting glycogen back to glucose (Increases BG levels)

Answer 140

is the process of glycogen synthesis, in which glucose molecules are added to chains of glycogen for storage. (Decreases BG levels)

Answer 141

-translocation -lipogenesis - protein synthesis glycogenesis

Answer 142

- lypolysis - glycogenolysis gluconeogenesis

Answer 143

Benefits of stress - Warning system - improve productivity and concentration fights tiredness and fatigue ``` Long term effects of stress? - anxiety - depression - sleep problems - digestive problems heart problems ( like hypotension) ```

Answer 144

Stimulus- Stressful situation (fight or flight response) so low glucose levels Receptors- sensory receptors in AMYGDALA Modulator- hypothalamus initiates release of adrenaline and cortisol Effector- liver, skeletal muscle, cardiac muscle and all cells Response- flight or flight responses Eg. Increased heart rate and cellular respiration. Metabolic Processes of glyogenolysis, lipolysis and gluconeogenesis also increase Feedback- overcome stressor, high glucose levels in blood so increased energy production

Answer 145

AMYGDALA: It is a section of nervous tissue in the brain responsible for emotions, survival instincts and memory

Answer 146

Nerve impulses via Autonomic division - > adrenal medulla - > adrenaline

Answer 147

hypothalamus - > Adrenocorticotropic hormone releasing factor - > Anterior pituitary gland - > ACTH released - > reaches Adrenal cortex - > which then releases cortisol

Answer 148

Diabetes mellitus: Abnormally high blood glucose levels (hypoglycaemia). There are two types, a diabetic doesn’t produce enough insulin or their cells have an abnormal resistance to the effects of insulin

Answer 149

Type one diabetes Cause: - Type one is insulin dependent diabetes occurs because of a fault in the patients immune system causes the destruction of beta cells in the islets of langerhans of the pancreas. Beta cells are therefore not producing insulin, usually begins at childbirth Effects: - Beta cells cease producing insulin, glucose therefore cannot enter. - can lead to kidney failure and heart attacks - can cause blurred vision, increased thirst, increased blood pressure, frequent urination Treatment - Disease can be managed by giving a person insulin -Can’t be digested into alimentary canal so treatment is regular injections of insulin or; use of programmable pump that provides continuous supply of insulin under skin no actual cure

Answer 150

Stimulus: high glucose in blood Receptor: chemoreceptors in beta cells are damages Modulator: beta cells do not produce insulin Effector: liver, all cells, muscles and adipose tissue Response: little activity (glycogenesis, lipolysis, p.synthesis, translocation) Feedback: glucose remains high (Positive fb loop)

Answer 151

Receptor: becomes monitoring machine Modulator: injection or pump

Answer 152

Cause: Iifestyle disease caused by obesity or being overweight, risk increases when person has a diet high in fat, sugar, salt and low fibre, high blood pressure and smoking. Effects: - body is able to produce insulin but cells do not respond. - undiagnosed can lead to heart disease, stroke, kidney disease etc. - excessive hunger, thirst, fatigue Treatment: No cure but is managed by: careful diet, regular physical activity, maintaining healthy weight and only sometimes medications that stimulate secretion of more insulin from pancreas or stimulate receptors to be more sensitive

Answer 153

Type 2 diabetes feedback loop Stimulus: high blood glucose Receptor: chemoreceptors on beta cells Modulator: beta cells produces insulin Effector:insulin receptors on liver, muscle, adipose tissue (effectors) damaged Response: slow response (glycogenesis, lipolysis, p.synthesis, translocation) Feedback: glucose level in blood still high

Answer 154

Stimulus: keeping a healthy diet, lifestyle Effector: medication-> increases insulin sensitivity ( thence increase rate of response)

Answer 155

stimulus- high co2 level (byproduct of aerobic respiration) in bloodstream So increased hydrogen ion levels So decreased PH levels ( more acidic) Receptor: Chemoreceptors in medulla oblongata and aortic and carotid bodies in arteries Modulator: Medulla oblongata respiratory centre sends nerve impulses ( via intercostal nerve and phrenic nerve) Effector: Intercostal muscles ( from intercostal nerve) Diaphragm (from phrenic nerve) Response: Increased breathing rate and depth Feedback: Decreased co2 levels in blood So decreased H+ ion levels So increased ph ( neutral)

Answer 156

FOLP | FSH-> Oestrogen-> lutenising hormone-> progesterone

Answer 157

At the beginning of menstural cycle Low levels of estrogen and progesterone signal the anterior lobe of the pituitary gland to produce Follicle Stimulating Hormone (FSH) which Causing growth of ova. FSH begins the process of maturing a follicle.

Answer 158

FSH levels after a point begin to decrease and The follicle produces more estrogen.

Answer 159

The ruptured follicle (corpus luteum) then secretes progesterone and estrogen to continue to prepare the uterus for pregnancy

Answer 160

If the egg is not fertilized, estrogen and progesterone levels drop and, on Day 28, the menses begin.

Answer 161

Stimulus: Decreased o2 ( must be VERY low to stimulate a response) Receptor: Chemoreceptors in MO and aortic and carotid bodies Modulator: Medulla oblongata ‘respiratory center’ Via intercostal nerve and phrenic nerve Effector: Intercostal muscles Diaphragm Response:Increased breathing rate and depth Feedback: Increases o2 levels

Answer 162

Stimulus- no stimulus. Low co2 ( too low to stimulate breathing) Normal o2 levels (not low enough to stimulate breathing) Receptor- chemoreceptors and aortic and carotid bodies don’t detect changes Modulator- mo not instructed to initiate a response Effector- diaphragm and intercostal muscles are relaxed Response- no breathing Feedback- increased co2, H+, and decreased PH. O2 is used up. Lower gas concentration after enough time to stimulate a response

Answer 163

``` Caused when an airway swells and becomes inflamed and narrow Symptoms : Shortness of breath Wheezing coughing ```

Answer 164

Stim: high co2, H+, low ph Receptor: chemoreceptors in AC bodies and mo Modulator:mo Effector: diaphragm and intercostal muscles Response: bronchioles are narrowed ( inflammation and constriction due to a trigger so breathing rate and depth don’t increase much Feedback- co2 levels remain high, o2 decreases

Answer 165

Cause: Walls of airsacks in lungs (alveoli) weaken and rupture overtime reducing SA of lungs and amount of oxygen you get

Answer 166

Symptoms: Shortness of breath Wheezing Chronic cough

Answer 167

Stim: high co2, H+, low ph Receptor: chemoreceptors in AC bodies and mo Modulator:mo Effector: diaphragm and intercostal muscles Response: alveoli number has decreased so decreased SA and insufficient gas exchange Feedback- co2 levels remain high, o2 decreases Treatment would be at stimulus

Answer 168

Low water in bloodstream - > low blood volume - > low blood pressure - > higher salt conc - > higher osmotic pressure

Answer 169

Stimulus- low h20 concentration and high osmotic pressure Receptor- osmoreceptors in hypothalamus thirst center Modulator- hypothalamus thirst center Effector- cerebral cortex- frontal lobe =feel thirsty Response- behavioural (drink water) and water is absorbed in digestive system Feedback- increased h20 concentration and decreased osmosis pressure

Answer 170

Stimulus- low h20 concentration and high osmotic pressure Receptor- osmoreceptors in hypothalamus Modulator- hypothalamus-> nerve impulse-> post.pit.gland-> ADH released Effector- kidney ( distal convoluted tubule, collecting duct) Response- DCT+CD become more permeable -> ADH opens water channels and water is reabsorbed Feedback- increased h20 concentration and decreased osmosis pressure

Answer 171

Stimulus- high h20 concentration and low osmotic pressure Receptor- osmoreceptors in hypothalamus don’t detect Modulator- hypothalamus-> nerve impulse-> post.pit.gland-> no ADH released Effector- kidney ( distal convoluted tubule, collecting duct) Response- DCT+CD become less permeable -> ADH closes water channels and less water is reabsorbed Feedback- decreased h20 concentration and increased osmosis pressure

Answer 172

Alcohol- prevents ADH release from pit Caffeine- blocks ADH receptors

Answer 173

Stimulus-low h20 conc=increased osmotic pressure,high salt conc and low blood pressure Receptors- chemoreceptors+ osmoreceptors in hypothalamus and baroreceptors in AC bodies; kidneys Modulator- hypothalamus, ACTHRF, ant.pit.gland, ACTH, adrenal cortex, aldosterone Effectors- kidneys- loop of henele DCT Response- NA K pumps become active. NA is reabsorbed, K is secreted. This increases osmotic pressure as water moves from filtrate to blood stream to balance salt concentration Feedback- high H20= decreased Osmotic pressure, decreased salt concentration, increased blood pressure

Answer 174

Stimulus-high h20 conc=decreased osmotic pressure,low salt conc and high blood pressure Receptors- chemoreceptors+ osmoreceptors in hypothalamus and baroreceptors in AC bodies; kidneys Modulator- hypothalamus, ACTHIF, ant.pit.gland, ACTH not produced, adrenal cortex not targeted, reduced aldosterone Effectors- kidneys- loop of henele DCT Response- NA K pumps become deactivated. NA stays in filtrate, K stays in blood. = maintained osmotic pressure, water doesn’t move from filtrate. Feedback- low H20= increased Osmotic pressure, increased salt concentration, decreased blood pressure

Answer 175

``` S- high blood calcium R- chemoreceptors on thyroid M- thyroid releases calcitonin E- kidneys, intestines, bones R-osteoblasts build up bone, less reabsorption of calcium in kidney,decreased absorption of calcium in intestines F- decreased blood calcium ```

Answer 176

Nerve impulses, muscle contraction and bone strength

Answer 177

``` Homeostasis: The maintenance of a constant internal environment. - 37° temperature - body fluid ( water) - ion concentration - glucose blood pressure ```

Answer 178

1. stimulus 2. receptor 3. Modulator 4. effector 5. Response 6. Feedback stimulus stage A change in the environment, initiates a response. receptor stage Sensory cells detect the stimulus modulator stage The modulator is a control centre which processes the message from the receptors effector stage Effectors are Muscles, glands or cells which receive messages from the modular response stage The appropriate response is made by the effector feedback stage The response changes the original stimulus. Can either be positive feedback or negative. If POSITIVE= process enhances stimulus If NEGATIVE= process opposes stimulus

Answer 179

``` Thermoreceptors Chemoreceptors Pressoreceptors Nocireceptors Baroreceptors ```

Answer 180

thermoreceptors receptors detect Heat and cold. temperature change osmoreceptors? Detect changes in osmotic pressure ( pressure applied to solvents is osmosis?) chemoreceptors? Detect changes in blood oxygen and carbon dioxide pressoreceptors? Detect changes in blood pressure baroreceptors? Detect changes in blood pressure. nocireceptors? Respond to damaging or potentially damaging stimuli ( pain receptors)

Answer 181

N: Electrical impulses and neurotransmitters E:Hormone

Answer 182

N: Nerve impulses are Transported Along the membrane of neurons E: By bloodstream

Answer 183

N: muscles, gland cells (Effectors) and other neurons E: All body cells

Answer 184

N: Usually local and specific responses E: May be very general and widespread

Answer 185

N: Rapid response- within milliseconds E: Slower response- from seconds to days

Answer 186

N: Brief- stops quickly when the stimulus starts E: Longer lasting and may continue long after the stimulus has stopped

Answer 187

Nervous system:Communication network and control center of body. It is involved in maintenance of homeostasis inside the body, a task it shares with the endocrine system

Answer 188

Central nervous system | Control centre consisting of brain and spinal cord

Answer 189

Nerves that connect central nervous system with the receptors, muscles and glan

Answer 190

Neurons | Nerve cells which are the basic structural and functional units of whole nervous system

Answer 191

Myeline sheath: Layer of fatty material that covers axons acting as an insulator, protecting axon from damage and increasing the speed of the nerve impulse.

Answer 192

Neurilemma- membrane that wraps around the myelin sheath and helps repair damaged fibres

Answer 193

Axon: Long extension of nerve fibres from cell body. It carries nerve impulse away from nerve cell body to another nerve cell or effector.

Answer 194

Dendrites:Short extension of cytoplasm of cell body. They Often have many branches, receive messages from other neurons and carry them towards the cell body.

Answer 195

Cell body:Soma: contains nucleus and many other organelles

Answer 196

Node of ranvier: Interval of gaps along the axon

Answer 197

Schwann cells: The cell that wraps around a nerve fibre forming the myelin sheath.

Answer 198

Motor end plate- point where branches of axon meet the muscle fibres

Answer 199

Receptors found on Sensory neurons only

Answer 200

Functional - sensory - motor - interneuron

Answer 201

receptor neurons | carry messages from receptors in the sense organs or in the skin to the CNS ( brain and spinal cord)

Answer 202

effector neurons | - carry messages from the CNS to the muscles and glands ( the effectors)

Answer 203

association neurons, connector neurons or relay neurons | located in the CNS and are links between sensory and motor neurons

Answer 204

Multipolar- 1 axon, multiple dendrites Bipolar- 1 axon and 1 dendrite Unipolar- 1 axon extension and cell body to one side of it.

Answer 205

Transmit information from the receptor to the effector to respond rapidly to stimuli with the purpose of maintaining homeostasis

Answer 206

nerve impulse starts in dendrite

Answer 207

Nerve fibre: Any long extension of cytoplasm for a nerve cell body

Answer 208

Nerve: Bundle of nerve fibre held together by connective tissue

Answer 209

1. Resting neuron contains POTENTIAL ENERGY. This comes from the difference between the electrical charge on the inside and outside of a neuron. 2. Nerve impulse = ACTION POTENTIAL A change in the EXtracellular fluid and intracellular fluid generates an impulse that propagates ( moves) along neuron. ~The nerve impulse undergoes polarisation, depolarisation, repolarisation, and hyperpolarisation~ Polarisation there is a + EF (due to sodium) & - IF (due to large - proteins). RESTING MEMBRANE POTENTIAL= -70mv potassium readily diffuses through cell membrane into EF. The Na/ K pump actively pumps potassium back into cell. Depolarisation there is a - EF & + IF ( charges have swapped) - a stimulus opens some Na+ voltage gated channels and Na+ moves into cell causing cell to become positive . - when membrane potential reaches -55mv an all or none response occurs - all Na+ voltage channels open in that area causing an influx of Na+ = positive IF Repolarisation Charges return to + EF & - IF - Na+ ions diffuse through IF causing in adjacent parts of the neuron to depolarise. Na+ also stimulates k+ voltage gate channels to open. - k+ moves out of the cell into the EF making it more positive. Thence IF is - charged ( large - proteins) and Charges are restored - This process of repolarisation generates ACTION POTENTIAL which stimulates the Na+ V.G channel in adjacent areas to open. - the Na+/ K+ pump restores ionic distribution Na+ out and K+ in. While the cell segment is restoring back to polarised state. It is in REFARACTORY PERIOD. This prevents the neuron from being stimulated again and prevents the nerve impulse from travelling backwards Hyper polarisation - the charges is more negative than resting ( in the cell?) causing K+ V.G to close - K+/Na+ pump is restoring the ionic distribution - cell is in refractory period and cannot be restimulated and the nerve impulse is prevented from moving backwards

Answer 210

Saltatory conduction- mylinated conduction | Continuous conduction- unmylinated conduction

Answer 211

- nerve impulses Jump from one node to the next, allowing nerve impulses to travel much faster - it jumps from nodes because nerve fibres are insulated from the extracellular fluids at the nodes of ranvier and ions cannot flow between the inside and outside of the cell membrane and action potential cannot form.

Answer 212

- Each action potential generates another action potential just in front of it, this repeats along the length of the whole membrane depolarisation in one area of the membrane causes a local current flow between neighbouring areas on the membrane.

Answer 213

Nerve impulse: Electrochemical charge that travels along nerve fibre.

Answer 214

Neuromuscular junction: Junction between branches of a motor neuron and a muscle fibre; also called the motor end plate Synapse: Junction between branches of adjacent neurons. Messages are passed across the synapse. Messages are passed across the synapse

Answer 215

Action potential causes depolarisation of axon terminal membrane, causing calcium V.G channels to open causing calcium to enter the cell. Calcium ions bind to the synaptic vesicles which contain neurotransmitters. These vesicles move and then bind to the presynaptic membrane allowing neurotransmitters to be released via exocytosis into synaptic cleft. Neurotransmitters diffuse across the cleft and bind to receptors. i.e sodium ligand channels. Protein channels open causing sodium to enter the cell causing depolarisation of post synaptic membrane Action potential probates through post synaptic membrane. Neurotransmitters are broken down and removed from receptor mediated proteins. i.e Aceylcholinenesterase breaks down Acetylcholine into Acetyl CoA and chlorine. Acetyl coa and chlorine are then recycled, taken up into the cell via endocytosis and converted back into acetylcholine at the axon terminal

Answer 216

Neurotransmitters: Molecules that carries a nerve impulse across a small gap between branches of adjacent nerve cells,

Answer 217

Somatic- synapse | ANS- ganglion

Answer 218

Parietal - It is in between the frontal and occipital lobe - primary sensory strip and association area processes tactile information, pain etc. frontal lobe - front of the brain - voluntary control of muscles - judgement, emotions, motivation and memory categorising, thinking and expressive language occipital lobe - Helps with vision behind the parietal lobe temporal lobe - olfactory (smelling) and auditory areas - speech auditory processing processing of emotional responses

Answer 219

- largest part of brain - divided into four lobes - cerebral cortex is its outer layer - below cerebral cortex is white matter convoluted surface Function of cerebrum? Frontal- primary motor cortex, responsible for voluntary movement of muscles, judgement and emotions Temporal- olfactory, auditory processing and emotional responses Occipital- vision Parietal- processing tactile information, pain ect. Sensory association area

Answer 220

- 2-4cm thick - outer surface of cerebrum - grey matter Function of cerebral cortex! Higher order functions such as thinking, reasoning, memory, learning and conscious awareness of surroundings

Answer 221

Front of brain... Frontal lobe function? -Primary motor cortex - responsible for voluntary control of muscles forming strong memories, thinking, reasoning and expressive language

Answer 222

- wide band of nerve fibres that lie underneath cerebrum at the base of the longitudinal fissure nerve fibres cross from one cerebral hemisphere to another allowing communication between sides Corpus callosum function? Communication between two hemispheres

Answer 223

- Large - dual lobed - mass of grey matter - beneath cerebral cortex Function of thalamus? - directs nerve impulses to correct parts of brain - relate sensory motor signals to cerebral cortex receives auditory and visual signals

Answer 224

- middle of the brain, can’t be seen from outside small Function of hypothalamus? - involved in homeostasis - eg, regulation of autonomic nervous system ( regulation of heart rate, blood pressure etc.) regulation of body temperature , food and water intake, patterns of waking and sleeping and control of urinary bladder

Answer 225

- ductless - middle of the base of skull - pea sized - below hypothalamus Function of pituitary gland secretes hormones directly into bloodstream and produces hormones for various bodily functions

Answer 226

- part of brain stem - a bulge Function of pons - message station that directs Impulses - relays signals from forebrain to cerebellum - has sensory soles in hearing, taste and facial sensations

Answer 227

- roughly cylindrical in structure - extends from the large opening at the base of the skull to the second lumbar vertebrae - about 44cm - enclosed in vertebrae canal and bone cross section shows grey matter at center surrounded by white matter (g matter is H shape ) Function of spinal cord -Carry sensory impulses up to brain and motor impulses down from brain integrate certain reflexes (fast automatic responses)

Answer 228

- under rear part of cerebrum - second largest part of brain - surface folded into series of parallel ridges - outer folded part is grey matter inside is white matter that branches to all parts of cerebellum Function of cerebellum? - Control over fine body movement, posture, balance and coordination of voluntary muscle movement does this by receiving sensory information from inner ear ( for posture and balance) and from stretch receptors in skeletal muscles

Answer 229

- continuation of spinal cord - 3cm long - extends from where spinal cord enters skull nerve fibres pass through going to and from parts of brain Function of medulla oblongata Cardiac centre- regulates the rate and force of heart rate Respiratory centre- controls rate and depth of breathing Vasomotor centre- regulates diameter of blood vessels + others they regulate reflexes of swallowing, sneezing and vomiting. - centres are controlled by higher centres in the brain.

Answer 230

Myelinated

Answer 231

Unmyelinated

Answer 232

Saltatory = 140 m/s Continuous= 2 m/s

Answer 233

Sensory - unipolar - myelinated - sense receptors on the end of the axons. Dendrites are attached to receptors axon terminals of on the opposite side of the axon Structural features of interneurons - multipolar - multipolar dendrites surround cellbody Structural features of motor neurons - multipolar - mylinated effectors on one end and dendrites on other surrounding cell body

Answer 234

Either via the after afferent division (sensory) of the Efferent division (motor) Afferent pathway? Going towards the brain 2 afferent pathways —SENSORY ( towards CNS)—- Somatic sensory: info from skin and muscles Visceral: information from internal organs Efferent pathway? (Exiting) going away from the brain to the internal organs and glands 2 efferent pathways —motor division (away from CNS)—— Somatic division: sends impulses to skin and muscles Autonomic division: sends impulses to involuntary muscles

Answer 235

They come from either somatic sensory neurons or visceral sensory neurons

Answer 236

Somatic- sends impulses to skin and muscles | autonomic- sends impulses to involuntary muscles, organs

Answer 237

Via the sympathetic route or the parasympathetic route. Sympathetic- controls body when active, fight of flight. It’s a longer neuron pathway so it’s the slower system Eg. Heart> increased rate, lungs> dilates bronchioles, blood vessels of skin> constricts Parasympathetic- controls body when resting, quiet. Very short neurons, faster Eg. Heart> decreased rate, lungs> constricts bronchioles, blood vessels of skin> little effect

Answer 238

To the CNS and back

Answer 239

- dorsal root with ganglion ( lump) - dorsal root (back of spine, vertebrae) - sensory neuron - ganglion ( cell bodies on sensory neurons) - interneuron - central canal ( inside H shaped grey matter) - white matter ( surrounding H) - motor neuron through ventral root

Answer 240

Central Canal

Answer 241

A group of cell bodies ( somas)

Answer 242

Protective reflexes - born with them Eg. Sneezing, coughing, blinking - protect the body from injury - up spinal cord only Acquired reflexes reflexes learnt through constant repetition. Eg, maintenance of balance while riding a bike, jamming brakes on car to avoid dangerous situations or flinching when ball is coming

Answer 243

- vertebrae ( bones forming the backbone) -vertebral Canal ( fat, blood vessels, connective tissue which provide extra cushioning) meninges and cerebrospinal fluid

Answer 244

Sensory neuron sends the impulse to an interneuron which sends the impulse to another a sensory neuron which leads it up the ascending tract to the brain. A motor neuron then brings it back down the descending tract sending the impulse to an interneuron which transmits the message to another motor neuron which takes it to the effector.

Answer 245

a nerve containing both sensory and motor fibers

Answer 246

-Skin: It is the outermost layer it acts as a barrier -periosteum: Acts as a layer of connective tissue which surrounds bone - bone: Brain is protected by the skull and the cranium which house it. Vertebrae also protect spinal cord by covering it meninges consisting of the Dura Mater, arachnoid and Pia Mater Layers of meninges Dura Mater Arachnoids mater Pia Mater

Answer 247

``` Dura Mater Pain sensitive, has own blood supply, sticks closely to bones of skull but on inside of vertebral Canal is not so close fitting, tough and fibrous, Toughest outermost layer of meninges ``` ``` arachnoids mater - - middle layers - filled with web of collagen - has cerebral fluid - no blood vessels contains CSF ``` Pia Mater - sticks closely to surface of brain and spinal cord - very tender - rich supply of blood vessels which provide nutrients to nervous tissue - helps produce CSF

Answer 248

Where is CSF found Occupies space between inner and middle layer of meninges. Circulated through cavities in brain and through a canal in center of spinal What does Cerebral spinal fluid do? -protection: acts as shock absorber Support: brain floats in it Transport: takes nutrients to brain cells and spinal cord, removing wastes

Answer 249

Adjustment of internal environment (homeostasis)

Answer 250

Response to the external environment

Answer 251

Effector affected in the Autonomic division? Heart muscles, involuntary muscles and glands Effector affected in the Somatic division? Skeletal( voluntary) muscles

Answer 252

Efferent outwards pathway for the Autonomic division? To nerve fibres from the CNS to the effector with a synapse in a ganglion Efferent ( outward) pathway for somatic division? One nerve fibre from the CNS to the effector; no synapse or ganglion

Answer 253

Autonomic division, type of neurotransmitters at effector noradrenaline Somatic division, type of neurotransmitters at effector Acetylcholine

Answer 254

Usually involuntary

Answer 255

Usually voluntary

Answer 256

What type of nerves go to the target organ in Autonomic division? sympathetic and parasympathetic What type of nerves go to the target organ in somatic division? One set, somatic

Answer 257

What is the effect on the target organ in Autonomic division? Excitation or inhibiton What is the effect on the target organ in somatic division? Always excitation

Answer 258

Excitation:the process by which nerve cells use their “presynaptic terminals” to stimulate the next receiving nerve cell in line to transmit information onward Inhibition:kind of synaptic potential that makes a postsynaptic neuron less likely to generate an action potential.

Answer 259

Groups of nerve cells in medulla oblongata, hypothalamus and cerebral cortex

Answer 260

Reflexes: Rapid and autonomic responses to a change in the environment. They are coordinated by the spinal cord on an involuntary bandits. Once the reflex has occurred, an impulse is sent to the brain and the person becomes aware of the situation.

Answer 261

4 important properties of reflexes 1. Stimulus 2. Involuntary and rapid 3. Small no. Of neurons involved 4. Stereotyped (same way each time)

Answer 262

Reflex arc route 1. Sensory receptor detects stimulus and generates nerve impulse in a sensory neuron (pain= nociceptor) 2. Sensory neuron carries impulse into the spinal cord via the dorsal root ganglion and Dordal root 3. Impulse transmitted into an interneuron in the grey matter of spinal cord 4. Interneuron transmits impulse to a motor neuron. Motor neuron carries impulse out via the ventral root to the effector. 5. Effector responds to remove the stimulus 6. While reflex is being carried out, an impulse is sent to the brain so an individual becomes aware of the situation. Upper sensory neuron carries the message

Answer 263

A group of individuals that share many characteristics and are able to interbreed under natural conditions to produce fertile offspring

Answer 264

Alternative forms of a gene. The pairs of alleles each person inherits from their parents control and determine the characteristics of that individuals

Answer 265

Populations: A group of organisms of the same species living together in a particular place at a particular time

Answer 266

Geneticist: Scientists who specialise in the study of inheritance; prefer to consider the characteristics of the population as a whole and not those of the individuals that make up the population. They find it convenient to pool genotypes of all the individuals capable of reproducing ‘gene pool’

Answer 267

Gene pool: Sum of all the alleles carried by the members of a populatio

Answer 268

Allele frequencies: How often each allele of a gene occurs in a population

Answer 269

Mutations: A permanent change in a gene or chromosome leading to new characteristics in an organism, they may occur suddenly or purely by chance. There are 2 main types: gene mutations and chromosomal mutations

Answer 270

Mutant: An organism with a characteristic resulting from a mutation

Answer 271

Gene mutation: An alteration to a single gene, occur during replication of DNA before cell division. They are Changes to a single gene so that the traits normally produced by that gene are changed or destroyed Eg. albinism, duchenne, cystic fibrosis Chromosomal mutations: A change to the structure and or number of chromosomes in a organism. A mutation in which all or part of a chromosome is affected (a change to the structure and or number of chromosomes in an organism)

Answer 272

Mutagenic agent/ mutagen: An environmental agent that increases the rate of mutation Eg, mustard gas, Sulfur dioxide, X-rays and radiation from radioactive waste

Answer 273

Somatic mutations: A change occurring in a gene in a body cell( not gamete), reproductive cells are not affected as mutant body cell divides Eg. Many cancerous growths Germinal/ germline mutations: occurs in gamates. A change in the hereditary material in the egg or sperm that becomes incorporated into the DNA of every cell in the body of offspring. Eg. Diseases like phenylketonuria (PKU) can arise through mutation during formation of gametes and can be passed in to an offsprin

Answer 274

- a change in just 1 base in a DNA molecule. - it could alter a protein, have no effect at all of prevent the protein from being produced = DNA for a particular protein is altered= protein for which it codes may be abnormal of missing = can have an enormous effect on entire body Eg. Albinism, duchenne dystrophy, cystic fibrosis

Answer 275

Point mutation marked by absence of pigment from hair, skin and eye.

Answer 276

Recessive alleles inherited from homozygous condition resulting in death of embryo, foetus or child. - some lethal recessive masked by dominant allele Eg. Tay each disease

Answer 277

affect gene pool as ppl who inherit two such alleles would die before their alleles could be passed onto next generation do proportion of lethal recessive alleles in the gene pool would generally be reduced

Answer 278

Deletion: When part of a chromosome is removed eg. cri du chat Inversion: When a section of DNA breaks and is reattached in reverse order and orientation . This changes the order of genes on a chromosome and may disrupt the pairing of homologous chromosomes during meiosis Eg. haemophilia A Translocation:When part of a chromosome breaks of and is rejoined to the wrong chromosome Nondisjunction: When during meiosis a chromosome pair does not seperate and one daughter cell has an extra chromosome and one daughter cell has one less than not,al number. ( sometimes referred to aneuplody- a change in chromosome number) Trisomy – extra chromosome Monosomy – lacking one chromosome Duplication: When a section of a chromosome occurs twice, this may happen if part of a chromosome breaks of and joins to the wrong chromatid Eg. Charcot Marie tooth disease

Answer 279

Down syndrome: Trisomy 21 - child has 3 of chromosome 21 instead of 2 - non disjunction

Answer 280

when extra part of 1 chromosome attached to another chromosome

Answer 281

Evolution: The gradual change in the characteristics of a species over a long period of time.

Answer 282

Variation: the differences that exist between individuals or population of species Gene expression: refers to the ‘switching on’ of a gene and the DNA code is converted into the structures and functions of a cell

Answer 283

Speciation: The process of new species developing

Answer 284

Mechanisms for evolution: - genetics and inheritance ( sexual reproduction, genetic disease, mutations) - gene flow and barriers - random genetic drift ( bottle necking and founder effect) - natural selection

Answer 285

Mutations: A change in a gene of chromosome leading to new characteristics Mutant: An organism with a characteristic resulting from a mutation

Answer 286

- All somatic mutations: change occurring in a gene in a body cell ( not gamete) - Germline mutations: a change in the hereditary material in the egg or sperm that becomes incorporated into the DNA of every cell in the body of offspring eg. Phenylketonuria (PKU)

Answer 287

Gene mutations and chromosomal mutations

Answer 288

- random assortment: of chromosomes during meiosis ( lots of possible combos ) - crossing over: of chromatids during meiosis ( changes in sequence, recombination of alleles) - non disjunction: chromosomes fail to seperate during meiosis - random fertilisation: sperm can fertilise any egg

Answer 289

``` mutations: permanent changes in DNA of a chromosome #Mutations are the ultimate source of variation introducing new alleles into a population: new alleles may be favourable or unfavourable to survival# ```

Answer 290

When nature favours one set of alleles at the expense of others - causing changes to allele frequencies in a gene pool, it is not random.

Answer 291

Random genetic Drift: The occurrence of characteristics in a population as a result of chance rather than natural selection; only occur in small populations. it is random/ non directional and only contributes to change in frequencies of alleles in a gene pool

Answer 292

Founder effect: A type of genetic drift that occurs when a new population is formed by a small number of individuals; the small size of the sample can cause marked deviations in allele frequencies from the original population

Answer 293

Migration: gene flow from one popular to another if immigrants from another country bring alleles not already in population allele frequencies for that gene will be altered

Answer 294

Barriers to gene flow: - environmental pressures that inhibit the amount of interbreeding in populations - isolation results in development f seperate gene pools Geographical barriers- oceans, mountains, large lake systems, deserts, expansive ice sheets ( most common barriers for early humans) Sociocultural barriers- people of different religions, who speak different languages, economic statuses, educational backgrounds, social positions

Answer 295

When populations are reduced to low numbers by disease, predation or periods of climate change. ( population crash is not selective but may affect all phenotypes equally) - populations may recover ( having squeezed through a ‘bottleneck’ of low numbers) and return to previous levels but with reduced genetic diversity

Answer 296

Wind, ocean, human interference, animals, swimming, finding their way onto a boat,

Answer 297

The process by which a species becomes better adapted to its environment; those individuals with favourable characteristics have a survival advantage and so pass those characteristics on to subsequent generations

Answer 298

What influences natural selection: Selective pressures- any phenomena which impacts upon the behaviour and fitness of living organisms within a given environment Types of selective pressures Abiotic ( non living) and biotic ( living) Abiotic pressures examples Access to water, ability of bodies to use water, access to clothing and shelter, exposure to UV Biotic pressures examples Eg. Access to food, availability of mates, predators/ prey relationships, diseases

Answer 299

- variation: all members of a species may vary. Variations are passed on. ( favourable characteristics suited for environment = survival of the fittest) - birth rate: all organisms reproduce at a rate far greater than that at which their food supply and other resources increase. ( normally resulting in overcrowding) (Exessive birthrate + limited resources =struggle for existence ) natures balance- although birth rate of organisms is high, each species numbers tended to remain at relatively constant level

Answer 300

Ppl with long bodies and short limbs ( eskimos) have smaller SA in relation = lose heat less in very cold environments Ppl with short bodies and long limbed ( black Africans have larger SA so lose heat more effectively and survive better in hotter environments also sickle cell Armenia is an example ( presence of malaria acts as a selective agent for sickle cell allele)

Answer 301

Any factor that causes the death of organisms with certain characteristics but has no effects on individuals without those characteristics

Answer 302

``` total sum of all alleles of all the genes of all individuals in a population at any one time. They can be used to compare populations at different times or locations # Gene pools are dynamic, with changes in allele frequency caused by: mutations differing selection pressures random genetic drift, including the founder effect changes in gene flow between adjoining groups # ```

Answer 303

Genetic diseases: Diseases that result in changes to allele frequencies in a gene pool. An allele causing an inherited fatal disease is expected to gradually be eliminated from a population because people with the allele would die and would not pass it on to the next generation. Eg, tay Sachs, sickle cell amenia ,thassemia

Answer 304

Tay sachs Causes: disorder of lipid metabolism that is inherited in an autosomal recessive pattern. Missing enzyme results in accumulation of fatty substance in nervous system. Effects: lethal recessive condition, leads to early childhood death Sufferers deal with muscle weakness, problems with coordination, rhythmic muscle contractions, stiff muscles, feeling faint or wasting away, difficulty swallowing, hearing loss, impaired voice, seizures, or vision loss Mode of inheritance: autosomal recessive Populations most likely to be affected: Ashkenazi Jew population due to population being small and isolated while heterozygous form of tay Sachs has increased resistance to tuberculosis. Treatment: none

Answer 305

Sickle cell amenia Cause: disorder of the blood caused by an inherited mutation in the gene hemoglobin. The abnormal hemoglobin causes distorted (sickled) red blood cells, red blood cells to become rigid, sticky and misshapen. effects: amenia - Sickle cells break apart easily and die leaving you without enough red blood cells Pain- when sickle-shaped red blood cells block blood flow through tiny blood vessels to your chest, abdomen and joints, Pain can also occur in bones swelling of hands and feet frequent infections delayed growth vision problems Mode of inheritance: autosomal recessive Populations which are most likely to be affected by sickle cell amenia? Africa and India

Answer 306

Causes: It’s caused by a mutation of either the genes for chromosome 11 or the genes for chromosome 16. There are a number of thalassemia mutations. Effects: - fewer haemoglobin and red blood cells, may cause anemia . - Symptoms include fatigue, weakness, pale or yellowish skin(jaundice), facial bone deformities, slow growth, abdominal swelling and dark urine Mode of inheritance: autosomal recessive Populations most likely to be affected: occurs mostly in African-American populations, people of Mediterranean, particularly Greece and Italy. and in people of southeast Asian ancestry. Treatment: blood transfusions, bone marrow transplants

Answer 307

Biotechnology: Any technological application that uses biological systems/ living organisms

Answer 308

Genomics: study of whole sets of genes and their interactions

Answer 309

Gene probing DNA profiling DNA sequencing Gel electrophoresis Polymerase chain reaction Cloning Genetic engineering (recombinant DNA) Restriction enzymes Ligase enzyme Plasmids Transgenic organisms

Answer 310

They come from in bacteria where they restrict the duplication of infecting viruses by cutting up the invading viral DNA

Answer 311

Scientists use them to cut DNA at recognition sites and restrict the duplication of bacteriophages

Answer 312

Blunt ends: Straight cuts made when a restriction enzymes make a clean break across the two strands of DNA. Both strands terminate in a base pair, it is harder to recombinate with them. sticky ends: Made when restriction enzymes produce a staggers cut resulting in fragments with sticky ends, sticky ends is a stretch of unpaired nucleotides in the DNA molecule that overhang at the break in the strand

Answer 313

a ligase enzyme is an enzyme able to join of recombine, seperate pieces of DNA. It’s found in bacterium. It’s useful in bio tech because it is only in the presence of ligase that single stranded breaks in phage DNA could be repeated= enables scientists to attempt own recombination experiments recombining DNA from different organisms, including different species

Answer 314

To be able to extract genes for further analysis and processing. Ie. comparison of code to establish evolutionary relationships and diagnosis of genetic disease-> treatment plans

Answer 315

- sample of DNA to be analysed is mixed with radioactive nucleotides and free nucleotides DNA replication is initiated (in lab conditions)

Answer 316

- separation of genes within a genome based in base pair length - restriction enzymes are used to cut DNA into individual genes use gel electrophoresis to form a DNA fingerprint

Answer 317

The process of using an electric current to seperate DNA across an agarose gel. - extract DNA from cells - cut DNA to small pieces w/ restriction enzymes - DNA is inserted at wells on negative end - add electric current and strands move towards positive end. Small fragments move further agarose gel is porous = DNA moves through spa

Answer 318

1. Denaturing- DNA sample is collected; specific gene is extracted using restriction enzyme. Heat is used to denature the DNA strand. Template strand is exposed. Copies are made by polymerase chain reaction (PCR) 2. Annealing- primer (known segment of DNA) is added. This indicates the site at which DNA polymerase is to attach and begin copying the DNA. 3. Elongation- DNA polymerase copies the template strand, adding free nucleotides (complementary to the template) 4. Termination- when ddNTP (A,T,C,G) is added, the copying process ends and the new strand of DNA is released . DNA segments of varying lengths can be then seperate using gel electrophoresis. Each DNA segment is a different length, by reading nucleotide order a sequence can be identified.

Answer 319

- identify location of a specific mutation - genetic counselling establishes evolutionary trends/ relationships

Answer 320

A specific sequence of nucleotides at which an enzyme cuts a strand of D

Answer 321

- plasmid is selected based in whether or not DNA can be easily inserted into it. -cut using the same restriction enzyme used to extract desired gene (ie human insulin) -DNA segment is inserted into plasmid- DNA ligase bonds to form = recombinant DNA - recombinant DNA is inserted into a transgenic organism transgenic organism capable of transcribing the recombinant DNA and thus performs protein synthesis to manufacture the desired gene

Answer 322

3 and 5 prime indicate the carbon number in the DNA sugar backbone, it gives DNA strand a direction.

Answer 323

2^(no. Of cycles) | Two to the power of (Number of cycles)

Answer 324

It acts binding site for DNA polymerase so DNA replication can happen.

Answer 325

PCR clones just DNA. Cloning is whole cell. PCR is more efficient and less costly

Answer 326

recombinant insulin made by....: Gene for human insulin is isolated from pancreatic cells. Human gene is inserted into vectors such as plasmid which is then inserted into bacteria or yeast. Insulin gene is then cloned in the bacteria or yeast. Resulting insulin percusor formed from the gene is extracted from the bacteria or yeast and purified for pharmaceutical use by diabetes patients.#

Answer 327

Denaturing- hydrogen bonds of the two strands of the target sequence seperate after being heated to 90°c. Annealing- mixture cools to allow short primer to attach/ anneal to each of the two DNA strands at the 3’ ends to act as starting points for elongation. Elongation- sample is heated to 75°c and starting at primer DNA polymerase copies and extends the strands adding complementary nucleotides to the template. Cycle is repeated multiple times to reproduce many copies of original templates.

Answer 328

Stages of cloning? 1. Grow human growth cell in culture Eg. Nerve cell for myelin sheath or pancreatic cells for the insulin gene. Human cells contain the gene of interest gene X 2. Isolate DNA from cultures human cell. Cut gene x from rest of DNA, at recognition site, using a restriction enzyme to create sticky ends 3. Isolate suitable plasmid vector from bacterial cell 4. Cut plasmid with same restriction enzyme used to cut gene x. Producing a plasmid with matching sticky end to the gene 5. Gene x is inserted into the plasmid by mixing the gene and the plasmids together. Some plasmids take up gene x. The sticky ends of the plasmid base pair with the sticky ends of gene x. 6. DNA ligase joins together, the sticky ends of the plasmid and the gene by covalent bonds 7. Recombinant plasmid is put back in bacteria. Plasmid added to growing bacterial culture. Some bacteria will take up the plasmid by the process of transformation. 8. Recombinant bacteria grown on an agar plate. Bacteria multiply and reproduce many copies of gene x. Gene has been cloned. Colonies of bacteria containing blonde gene can be identified and gene can be isolated for scientific or medical use.

Answer 329

Complete set of genetic information of an organism

Answer 330

Phage: Bacteriophage; virus that infects bacteria

Answer 331

Bacterial plasmid, viral phage or other such agent used to transfer generic material from one cell to another

Answer 332

replacing faulty genes with functional genes and is being used for: Cystic fibrosis Huntington’s disease Gene therapy can be administered... In vivo: genes are transferred to the body using vectors such as viruses, plasmids or liposomes Ex vivo:cells with faulty genes are removed from the body and the fictional genes are inserted in the laboratory. Cells grow containing the functional gene and are injected back into the body.

Answer 333

a cell that can differentiate into different cell types and proliferate ( reproduce itself)

Answer 334

can differentiate into any cell type including placental. Is found in zygote. Pleuripotent: can differentiate into embryonic cell types. Found in embryo blastocyst.

Answer 335

can differentiate into several cell cell types- adult stem cells

Answer 336

Cell replacement therapy: The replacement of damaged cells with healthy ones Tissue engineering: the rebuilding of damaged tissues by the use of biology, medicine and engineering

Answer 337

Synthetic hormone: a hormone produced artificially which is similar to those produced naturally in a living organism.

Answer 338

Hormone replacement therapy: giving hormones to replace those which are manufacturing or insufficient.

Answer 339

-Comparative studies: Biochemistry (DNA & proteins), Embryology, Anatomy (homologous structures) - vestigial organs - biogeography fossils

Answer 340

A diagram showing evolutionary relationships between organisms; also called a dendogram

Answer 341

EVRs: Endogenous retrovirus, Junk DNA. It is a viral sequences hat has become part of an organisms genome. Comparing humans and chimps, same evrs are found in the same locations on chromosomes. Mitochondrial DNA: Human mtDNA has been slowly diverging from the mtDNA from our original female ancestors and the amount of mutation is roughly proportional to the amount of time that has passed. #mtdna is used in comparative studies as it mutates faster than nuclear DNA# Protein sequences: can be compared, the more differences the less related. The less differences the more related.

Answer 342

Multidisciplinary field that combines all areas of biological science with computer science, statistics and applied mathematics to help understand biological processes In practical terms is use of computers to describe molecular components

Answer 343

Comparative geomatics: Is a field of biological research in which the genome sequence of different species are compared. It allows researchers to identify regions of similarity and difference,

Answer 344

Absolute dating and relative dating

Answer 345

The actual age

Answer 346

Tells you if one sample is older or younger than other fossil

Answer 347

Time it takes for radioactive elements to decompose by half | 1 half life of carbon is 5730

Answer 348

Potassium argon dating: Measures the rate of radioactive potassium decay to form calcium and argon

Answer 349

can only date volcanic rocks older than 100000 to 200000 | not all rock types are suitable for this method can only be used for volcanic rocks

Answer 350

: carbon 14 ( radioactive) decays to nitrogen, half life is 5730 years and ratio of C14:c12 provides an absolute date for the fossil

Answer 351

- amount of carbon 14 in air varies - material to be dated must contain organic compounds - requires at least 3 grams of organic material can not be used to date back more than about 60000

Answer 352

Dendrochronology: Ring dating, counting the centric rings of surface of cut tree trunk. Each ring= one year of growth Difference in width= indicates how favourable the growing season was

Answer 353

timber rarely preserved for more that a few thousand years | particular conditions necessary for the method do not occur often

Answer 354

- Study of layers of strata. They use two principles to do this - principle of superposition correlation of rock strata

Answer 355

Layer on top younger than the ones below

Answer 356

Matching layers of rock from different layers

Answer 357

Fossils or organisms that were on the earth for only a short period of time and are therefore useful in relative dating of rock strata

Answer 358

Index fossils allow for more precise relative dating. They are used to define and identify geological time periods as they were only in existence for a specific time. Eg, fossilised pollen grains

Answer 359

Relative dating method, when a bone is left in the soil fluorine ions which are present m water in the soil replace some of the ions in the bones So the older the fossil= more fluorine

Answer 360

- fluorine levels in water differs from area to area | can only compare fossils from the same location

Answer 361

PCR can be used to amplify minute amounts of DNA so that can be used to facilitate the sequencing of the genome. Can be Useful with fossils where sometimes only small amounts of DNA may be available

Answer 362

Can be invaluable in tracing ancestry and relationships btwn individuals and groups

Answer 363

One of a group of proteins that appear to be in all species from bacteria to humans. Eg. cytochromes

Answer 364

Comparing the very early stages of the development of organisms

Answer 365

Organs that may have once been important but have lost or changed their functions. ``` Examples: Nicitating membrane Muscles to move ears Wisdom teeth + pointed canines Nipples on males Hair on body Appendix Coccyx ```

Answer 366

Evidence of or remains of an organism that lived long ago | Eg. footprints, burrows, faeces or impressions of an animal or plant

Answer 367

» Sometimes soft tissues are preserved but it is mostly hard tissues such as bones that are fossilised. Therefore, for ideal conditions of fossilisation, there will still be hard body parts present. » Rapid burial by sediments protects the remains from scavengers and mechanical damage » Absence of decay: » An alkaline environment favours the preservation of hard tissues » An acidic environment favours the preservation of soft tissue, as long as there is no oxygen present, e.g. a bog

Answer 368

Objects that have been deliberately made by humans eg. stone heads, carvings and charcoal from cooking fires

Answer 369

A more refined technique that can be used to date a sample as small as 100 micrograms

Answer 370

``` Absolute dating methods Dendrochronology Carbon 14 Protactinium Uranium thorium Potassium argon Electron spin resonance Fission tracks Thermoluminescence ```

Answer 371

Brachiator: Brachiators a type of primate mostly from the family they use their arms to move from tree branch to tree branch, through a process called brachiation. Their arms are longer than their legs, and are much more powerful. All primates except hominins

Answer 372

1.3 billion years | Can only be dated between 100 000- 200000

Answer 373

Examples: Bactericidal- penicillin treats several bacterial infections, some being skin , ear, throat infections Bacteriostatic- tetracycline treats bacterial infections of the skin, intestines, respiratory tract etc. How are they made?: ....

Answer 374

Natural passive: immediate, temporary immunity with no human intervention. When pathogens are passed from 1 person to another ( mother to foetus across placenta and amniotic fluid)

Answer 375

Natural active: takes time and is prolonged immunity with nohuman intervention. When Natural exposure to antigens occurs. ( chicken pox, flu virus)

Answer 376

Artificial passive:immediate, temporary immunity with human intervention. When antibodies are injected into the blood stream. ( serious illness where immediate action is required eg, tetanus, diphtheria or if someone has a poor immune system )

Answer 377

Artificial active:takes time and is prolonged immunity with human intervention. Occurs when antigen injected into the body initiates an immune response to produce antibodies. ( vaccines, eg. Measles, mumps) it is preventative

Answer 378

Gene probing: A single stranded DNA or DNA used in genetic engineering to search for a particular gene or other DNA sequence

Answer 379

DNA profiling: a technique that uses the banding patterns of DNA fragments as means of identification; a DNA fingerprint is unique to a particular individual; also called DNA fingerprinting

Answer 380

DNA sequencing: The determination of the precise order of nucleotides (nucleotide sequence) in a sample of DNA. Separation based on length of DNA.

Answer 381

Gel electrophoresis: The process of using an electric current to seperate DNA across an agarose gel

Answer 382

Polymerase chain reaction: (PCR) A technique used in molecular biology for producing multiple copies of DNA from a sample; used in DNA fingerprinting and in identifying diseases. ( amplifys small amounts of DNA)

Answer 383

Cloning: Process of producing clones of organisms or clones of organisms or copies of cells or DNA fragments (molecular cloning)

Answer 384

Genetic engineering (recombinant DNA): (Recombinant DNA) , the procedures used to produce recombinant DNA; involve introducing DNA into a cell from a different type of organism or DNA that has been modified in someway

Answer 385

Restriction enzymes:An enzyme that cuts strands of DNA at a specific sequence of nucleotides Ligase enzyme:An enzyme that can catalyse process of joining short strands of DNA during replication ( ligation?)

Answer 386

Plasmids: In bacterial cell, small circular double stranded DNAs distinct from the main bacterial genome, composed of only a few genes and able to replicate independently within cells, apart form chromosomal DNA.

Answer 387

Transgenic organisms: An organism that has had DNA from another species introduced into it artificially

Answer 388

Organs that are similar in structure but are used in different ways

Answer 389

helper T cells- Release chemicals to sensitise and attract b and T cells. Chemicals released attract phagocytes which enhance the response

Answer 390

suppressor T cells- They release chemicals which reduce b and T cell activity. Reducing also excessive activity when antigen has been removed

Answer 391

Recognise antigen in further exposures; initiate secondary response

FINAL EXAM Y12 Flashcards

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