biomes study lol Flashcards

Question

Phenotype

Answer 1

observable physical (anatomical) and functional (physiological) characteristic expressed in an individual

Answer 2

the differences in DNA segments or genes between individuals and each variation of a gene is called an allele. caused by: – random mating between organisms – random fertilization – crossing over (recombination) between chromatids of homologous chromosomes during meiosis*

Answer 3

Aneuploidy – loss (monosomy, 2n-1) or gain (trisomy, 2n+1) of chromosomes – Result from non-disjunction during meiosis

Answer 4

Sickled cells block capillaries – Oxygen deprivation – Pain – Organ damage Protective against malaria

Answer 5

A three base-pair deletion in the gene for cystic fibrosis trans membrane protein (CFTR) on chromosome 7 (non-frameshift mutation)

Answer 6

A single gene affecting more than one trait

Answer 7

– Some autosomal traits are considered to be sex-influenced eg male pattern baldness – Baldness in males is an autosomal dominant trait – Female baldness only occurs when the gene is homozygous recessive

Answer 8

– Some traits are more common in males because the allele responsible is carried on the X chromosome – which demonstrates the phenotype in the absence of a corresponding allele on the Y chromosome – Known as 'X linkage’ – Most X-linked diseases are recessive

Answer 9

– Resemble autosomal dominant disease – Excess number of affected females – All daughters of an affected father will have the disorder but there is no male-to-male transmission – A homozygous (affected) female will transmit the trait to all her offspring – A heterozygous affected female will transmit the trait to 50% of her offspring, both sons and daughters will be equally affected

Answer 10

A metabolic pathway is a series consecutive biochemical reactions in a cell - Involves the production and use of energy - Some reactions require energy - Some reactions release energy

Answer 11

– Heat energy in chemical bonds – Energy involved in molecular movement

Answer 12

– Energy involved in the randomness or disorder of a system

Answer 13

< 0 (negative) – the reaction is exothermic - heat is released or lost – The reaction is favourable – likely to occur

Answer 14

minimum energy needed to cause a reaction to occur is called the activation energy.

Answer 15

> 0 (positive) – the reaction is endothermic - heat energy is consumed – The reaction is unfavourable – unlikely to occur

Answer 16

1. Change in enthalpy of a reaction 2. Change in the entropy of a reaction 3. Temperature of a reaction

Answer 17

Energy is released when ATP is converted to ADP

Answer 18

– Active transport of substances across cell membranes – Electrical activity of nerves – Muscle contraction – Synthesis of large biological molecules – provides energy via ‘coupled’ reactions

Answer 19

- Enzymes are proteins that function as the catalysts in most body reactions >3000 different enzymes in a cell – specific for each reaction

Answer 20

1. Substrate(s)* attaches to the active site 2. An enzyme-substrate (ES) complex forms 3. Reaction occurs and products are released

Answer 21

‘If stress is applied to a system at equilibrium, the system reacts in such a way as to reduce/minimize the stress’

Answer 22

synthesise (build) larger molecules from smaller ones

Answer 23

breakdown larger molecules into smaller ones

Answer 24

1. Glycolysis 2. Citric acid cycle (TCA cycle or ‘Krebs’ cycle) 3. Electron Transport Chain (associated with oxidative phosphorylation)

Answer 25

– Metabolic reactions occur in specific sites within the cell

Answer 26

A process of GLUCOSE catabolism that produces the ATP needed by our cells.

Answer 27

- Converts 1 glucose (6C) to 2 pyruvate (3C) (pyruvic acid) - Glycolysis does not require oxygen - 2 ATP (uses 2 ATP but produces 4 ATP) - 2 NADH - 2 Pyruvate (also called Pyruvic acid)

Answer 28

- Occurs in cell mitochondria - Produces some energy (ATP) and cell waste CO2 and NADH and FADH2 From 2 rounds of the Citric acid (Kreb’s) cycle): * 2 ATP (from GTP) * 4 CO2 * 6 NADH * 2 FADH2

Answer 29

– Occurs in the inner membrane of mitochondria along a ‘chain’ of proteins embedded in the membrane – Involves movement of electrons (from hydrogens) along a ‘chain’ of proteins – Process requires oxygen (hydrogens and electrons are added to O2 to produce H20 in the final step – Process can theoretically generate loads of ENERGY (ie 32 or 34 ATP molecules)!!!!

Answer 30

1. NADH and FADH2 from the Citric Acid (Kreb’s) cycle are OXIDISED ie lose electrons which then move along ‘chain’ of cytochromes (and other proteins) 2. The hydrogens (H+) are pumped across the inner membrane of mitochondria 3. The energy generated by above 2 steps provides the energy for the reaction ADP + Pi ATP (involves enzyme ATP synthase) = OXIDATIVE PHOSPHORYLATION

Answer 31

Fertilisation to 2 week

Answer 32

2 to 8 weeks Critical period of development

Answer 33

8 weeks to term Growth and development

Answer 34

-fusion of ovum and sperm → zygote -Fertilisation takes place in uterine tube = day 0 or 2 weeks last menstrual period

Answer 35

Female causes 1. No ova due to menopause (this can occur as early as 30 years of age), tumour 2. Blocked uterine tube due to previous ectopic pregnancy, infections, tumour 3. Failure to implant due to hormonal imbalances, tumour Male causes 1. No/few sperm in semen due to cancer, genetic [non-obstructive azoospermia] 2. No sperm in semen due to blocked vas deferens eg. failed vasectomy reversal, neurological disorder Impotence or paraplegia [obstructive azoospermia]

Answer 36

1. Ovarian stimulation 2. Egg retrieval 3. fertilisation 4. embryo transfer Success rate: depends on age of mother, best before 40 years 22-34 50% success rate

Answer 37

* blockage in vas deferens * failed vasectomy reversal * neurological/psychological disorders preventing ejaculation expect Normal healthy Sperm Testicular/Percutaneous Epidydimal Sperm Aspiration (TESA/PESA) * IVF possible

Answer 38

* Abnormal or few non-motile sperm Testicular Sperm Extraction (TESE) * small piece of tissue extracted from testis * assumes small pockets of healthy sperm

Answer 39

– Non-motile or few motile sperm in semen – Immature sperm collected by ESA or TESE Injection of single sperm into egg, bypasses normal sperm selection processes Success rate <35 years 42% >41 years 25%

Answer 40

* 3–5 days after fertilisation one or more cells are removed from the embryo. * These cells are then analysed for a specific inherited disorder or chromosome abnormality * Results are available on day 5 following fertilisation * only healthy embryos are transferred into the uterus Uses: * sex selection (banned) * Inheritable disorders * Donor for older sibling

Answer 41

Organogenesis is the process by which the early embryonic tissues are converted into the organs of the body. It primarily occurs between week 4 to the end of week 8. At the end of this period the embryo is referred to as a fetus.

Answer 42

Period of rapid growth and development An 8-week fetus is about 3 cm in length (crown-rump), the newborn is about 36 cm (crown-rump)

Answer 43

1. 60% of pregnancies detected by hCG at 8-9 days after fertilization do not develop as clinically detectable pregnancies 2. 15-20% of recognisable pregnancies end in spontaneous abortion – 90% in the first trimester ~70% abnormal chromosomes 3. ~0.4% of pregnancies end in miscarriage >20 weeks. A miscarriage is the spontaneous termination of a pregnancy before fetal development has reached a level that is adequate for survival (usually present at about 20 weeks gestation) 4. ~3% of newborns have a malformation of surgical, medical or cosmetic importance.

Answer 44

Musculoskeletal 0.8% CVS 0.4% Urogenital 0.2% CNS 1.0% Face 0.1% Gastrointestinal 0.1% Other 0.3%

Answer 45

* 7.5% simple point mutations eg. cystic fibrosus, sickle cell anemia * 6% chromosomal anomalies eg. Trisomy 21 (Down’s sydnrome) * 20% multifactorial basis eg. familial cleft lip and palate * 5% teratogen eg. maternal diabetes (~3%), maternal infections (~4% eg. rubella, cytomegalovirus, toxoplasmosis), therapeutic drugs (~1%) and alcohol abuse. * 61.5% unknown

Answer 46

5-10 weeks- confirm pregnancy, confirm cardiac pulsation and measure crown-rump length for dating 10 week- fetus 6cm length heart beat can be monitored

Answer 47

8 to 10 weeks (usually 10 weeks). A small piece (villous) of the placenta is removed and cultured in the laboratory. Genetic results are usually available in ~2 weeks or sooner.

Answer 48

13-14 weeks At this stage, the fetus is surrounded by about 100 ml of amniotic fluid. About 10-20 ml of fluid is removed, the fetal cells are separated and grown in culture * used to genetic disorders o genetic results are available in about 2 weeks (PCR 2 days). o abnormality in chromosome number o some gene defects * can detect biochemical disorders

Answer 49

~ 14cm in length, weight ~190 g Usually performed at 16-18 weeks to look for congenital malformations. Sex of the fetus can usually be determined at this stage. * Accurate determination of foetal age * crown-rump length * Nuchal fold thickness

Answer 50

Problems with Prematurity: (a) lack of body fat – difficulty keeping warm; (b) respiratory distress due to lack of lung surfactant; (c) difficulty feeding; 90% of premature babies born who weigh 800 g or more will survive. For those who weigh 500 g or more there is 40-50% survival. Term birth newborn (38 weeks) weighs ~3500 g.

Answer 51

1. Maternal factors - maternal age - maternal nutrition - maternal disease - drug exposures

Answer 52

1. Respiratory system - low oxygen/high CO2 during labour - tying umbilical cord - full lung expansion takes several days 2. Circulatory system - delayed cutting of umbilical cord increases volume by 100ml - changes in flow of blood through the heart 3. Temperature regulation - rapid heat loss occurs at birth (1-2) -high skin temp: room temp - ratio skin surface area: body mass 4. Nutritional adaptation -foetal weight doubles in last 6 weeks in utero

Answer 53

-measure of asphyxia (lack of O 2) -score at delivery, and at 10 minutes -5 signs are measured < 2 indicates severe asphyxia has occurred, 3-5 moderate asphyxia 6-7 mild asphyxia.

Answer 54

* length * weight: prenatal conditions, particularly in 3 rd trimester * head circumference; brain developmen

Answer 55

Survival reflexes Protect infant until voluntary behaviours develop. -withdrawal from pain -response to cold – cry and tuck limbs toward body -reflex turning of head to side when face down -if submerged in water will hold breath

Answer 56

Rooting - turn head toward object that touches cheek -Sucking - suck anything in mouth -Swallowing -Tongue thrust - nipple in mouth causes tongue thrust, improves sea Other reflexes -moro reflex (startle) – arms are flung outwards -grasp reflex- baby grasps anything put in its palm -Babinski reflex – rubbing of the sole of the foot results in the toes flaring As the cerebral cortex matures these reflexes disappear

Answer 57

1. Longitudinal - one child measured at each age 2. Cross-sectional - each child measured only once, but large numbers of children are measured

Answer 58

Genetic factors -Rate of growth -Birth weight -Height Girls similar to mothers hight (0-7 and 8-16) -Down's syndrome- trisomy 21 Smaller stature -Turner's syndrome- single XO short stature, no adolescent growth spurt no ovaries, no breast development -Klinefelter's syndrome XXY very tall

Answer 59

Hypothalamus - controls secretion of hormones from the pituitary gland and can therefore indirectly control rate of growth. Growth hormone (pituitary)- affects mainly cartilage, not brain or repro system Thyroid hormone (thyroid)- Affects metabolically active tissue eg. brain Insulin (pancreas)- energy production These hormones control/determine growth Sex hormones are responsible for the adolescent growth spurt Abnormalities of the important hormones Growth hormone * hyposecretion ⇒ decreased growth rate : slow bone growth and maturation ⇒ dwarfism; brain normal. * hypersecretion ⇒ increased growth rate : abnormal increase in bone length ⇒ gigantism Thyroid hormone * hyposecretion ⇒ slow growth rate, sluggish ⇒ cretinism, dwarfism Sex hormones too early or too much ⇒ precocious puberty ⇒ slight or no effect on growth rate poss decreased adult height.

Answer 60

“tendency toward stability among interdependent elements”

Answer 61

The body functions within very limited parameters – * Body temperature – between 36.7 - 37.2oC – Physiological pH – blood pH – between 7.35 to 7.45 (avg. 7.40) – * Blood pressure - less than 120/80 mm Hg – Oxygen – 95% or higher – Fluid balance (volume and concentration) – Required for the optimal functioning of cells, proteins/enzymesCopyright - 2024

Answer 62

– Homeostasis is maintained by the nervous and endocrine systems – Nervous system * Central nervous system (CNS) and the peripheral nervous system (PNS) – Endocrine system * Cells that secrete hormones located in various organs and mostly function under the control of the CNS

Answer 63

Nervous system * Chemical messengers = neurotransmitters * Messages transmitted via neurons * Short-term responses (e.g., temp, blood pressure) Endocrine (or hormonal) system * chemical messengers = hormones * Messages transmitted in the blood * Long-term ongoing metabolic processes (e.g., blood glucose)

Answer 64

The ability of the body to respond to changes may be affected by: – age – general health – genetics – Physiological systems work to restore balance – Failure results in disease or death

Answer 65

– Requires Control Systems Negative feedback – Attempts to reverse disturbance/change – Body is brought back into homeostasis * Normal range is achieved Positive Feedback – attempts to accentuate the disturbance/change – Body is moved away from homeostasis * Normal range is lost – (Used to speed up processes)

Answer 66

Controlled Variable – is the parameter being controlled (temp, humidity, etc.) – will have a Set Point (e.g., air-con set to 22oC) Receptor (or Sensor) – Receives the stimulus and sends a message Control Center (or Controller, Integrating center) – Processes the signal and sends instructions Effector – Carries out instructions

Answer 67

– Anticipatory control mechanisms that permit the body to predict a change – Initiate a response that reduces movement of regulated variable outside normal range – Feedforward works in combination with feedback – Feedforward systems detect disturbances that could change controlled variable (in the future) and implement strategies to control the variable from changing Example: Hypothermia- Warm patient by placing individual between blankets, in a sleeping bag or wrap individual in a thermal blanket and cover head

Answer 68

– Failure in maintaining homeostasis results in disease – Diabetes – Heat failure – Obesity – (Ageing)

Answer 69

Direct Communication – Exchange of ions and molecules between adjacent cells across gap junctions – Occurs between two cells of same type – Highly specialized and relatively rare Paracrine Communication – Uses chemical signals to transfer information from cell to cell within a single tissue – Most common form of intercellular communication Endocrine Communication – Endocrine cells release chemicals (hormones) into bloodstream – Alters metabolic activities of many tissues and organs simultaneously Target Cells – Are specific cells that possess receptors needed to bind and “read” hormonal messages Hormones – Stimulate synthesis of enzymes or structural proteins – Increase or decrease rate of synthesis – Turn existing enzymes or membrane channels “on” or “off” Synaptic Communication – Ideal for ‘rapid communication’ – Occurs across ‘synaptic clefts’ – Chemical message is “neurotransmitter” – Limited to very specific areas

Answer 70

Chemically, all hormones are either: 1. lipid-soluble (e.g., steroids, thyroid hormones (T4, T3)] OR 2. water soluble (and lipid insoluble!) (amino acid derivatives, peptide hormones)

Answer 71

Hormone Receptor * Is a protein molecule to which a particular molecule binds strongly * A cell can respond to several different hormones * Different tissues have different combinations of receptors * Presence or absence of specific receptors determine hormonal sensitivity

Answer 72

Secreted by the follicles – Tetraiodothyronine – T4 (thyroxine) – Triiodothyronine – T3 – Thyroglobulin – precursor of thyroid hormones Thyroxine-Binding Globulins (TBGs) – Plasma proteins that bind about 70% of T4 and 80% of T3 entering the bloodstream Transthyretin (thyroid-binding pre-albumin – TBPA) and albumin – Bind most of the remaining thyroid hormones Thyroid-Stimulating Hormone (TSH) – Binds to membrane receptors – Activates key enzymes in thyroid hormone production – Absence causes thyroid follicles to become inactive * Neither synthesis nor secretion occurs -Calcitonin (secreted by parafollicular cells – also called C Cells) - Peptide hormone (chain of amino acids) - Important in calcium homeostasis

Answer 73

– Thyroid Hormones * Enter target cells by transport system * Affect most cells in body * Bind to receptors in: - Cytoplasm - Surfaces of mitochondria - Nucleus * In children, essential to normal development of: – Skeletal, muscular and nervous systems

Answer 74

Four Parathyroid Glands – Embedded in the posterior surface of the thyroid gland – Altogether, the four glands weigh 1.6 g Parathyroid Hormone (PTH) or parathormone – Produced by parathyroid (chief) cells in response to low concentrations of Ca2+ – Antagonist for calcitonin

Answer 75

– Hashimoto’s Disease – most common cause of hypothyroidism – body's immune system mistakenly attacks and slowly destroys the thyroid gland and its ability to produce hormones – Graves' Disease – most common cause of hyperthyroidism (overactive thyroid) – autoimmune disorder – can cause the gland to overproduce the hormone – disease is hereditary – Goiter – Non-cancerous enlargement of the thyroid gland – most common cause is iodine deficiency in the diet

Answer 76

– Sensory or afferent * Carries information from the PNS to the CNS – Motor or efferent * Sends information from the CNS to the periphery – Interneurons or association neurons * Generally located between motor and sensory neurons * Analyzes sensory input and coordinates motor output * Can be excitatory or inhibitory

Answer 77

– Highly branched – Receives input from 100’s to 1000’s of other neurons – Dendritic spines: – many fine processes – receive information from other neurons – 80–90% of neuron surface area

Answer 78

– Contains nucleus – Cytoplasm – Contains organelles that synthesize organic materials – Large number of mitochondria that generate energy – Free and fixed ribosomes

Answer 79

– Varies in length – Carries electrical signal (action potential) to target – Axon structure is critical to function

Answer 80

– By the exchange of ions – By the release of neurotransmitters

Answer 81

* Resting membrane exposed to stimulus * Na+ channel opens * Transmembrane potential rises ( towards 0 mV) * Depolarization occurs

Answer 82

– diameter – myelination – speed of action potentials

Answer 83

– Area where a neuron communicates with another cell, muscle or gland – Presynaptic cell: – neuron that sends message – Postsynaptic cell: – cell that receives message

Answer 84

– Are chemical messengers – Are packaged into vesicles – Are released at presynaptic membrane – Bind to receptors on postsynaptic membrane – Are broken down by enzymes – Are reassembled at synaptic knob

Answer 85

1. Excitatory NTs: – cause depolarization of postsynaptic membranes – promote APs 2. Inhibitory NTs: – cause hyperpolarization of postsynaptic membranes – suppress APs

Answer 86

1. Electrical synapses: – direct physical contact between cells 2. Chemical synapses: – signal transmitted across a gap by chemical neurotransmitters

Answer 87

-Are locked together at gap junctions (connexons) – Allow ions to pass between cells – Produce continuous local current and action potential propagation – Are found in areas of brain, eye, ciliary ganglia

Answer 88

– the number of years an individual can expect to live – was ~30 years in the pre-modern era – began to increase in the early industrialized countries in the early 19th century – global average has more than doubled since 1900 and is now above 70 years

Answer 89

– In 2018 the number of people older than 64 years old surpassed the number of children under 5 years old – Different countries face different challenges – Lower-income countries -->high fertility rates --> a very young population – High-income countries --> large elderly population --> changes in working- age populations

Answer 90

– Damage to DNA – Telomere shortening – Epigenetic malfunctions – Misfolding of proteins – Cell senescence – Stem cell exhaustion – Glycation – Inflammaging – Cell signalling pathways – Sirtuins (longevity genes)

Answer 91

– Non-genetic regulation of gene expression – Modification via methylation or demethylation – Histone modification – Post-transcriptional regulation

Answer 92

– a non-enzymatic reaction between sugars, such as glucose, and proteins, lipids or nucleic acids – Advanced glycation end products (AGEs) are proteins or lipids that have become glycated as a result of exposure to sugars – ROS accelerates AGE formation – In healthy individuals with normal blood glucose levels, glycation occurs gradually – Diet and lifestyle choices affect glycation – Yellowing of skin often seen prematurely in smokers is a sign of glycation – Smoking reduces antioxidants – AGE formation increases with age, smoking, poor diet and UV exposure

Answer 93

– The composition of the microbiome changes with age – Diet directly influences the gut microbiome – Alterations in microbiome is associated with disease – Altering the gut microbiome changes disease state

Answer 94

– an age-related increase in the levels of pro-inflammatory markers in blood and tissues – strong risk factor for multiple diseases

Answer 95

a family of signaling proteins involved in metabolic regulation – evolutionally conserved proteins

biomes study lol Flashcards

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