B1

Question 1

Look at the picture of the eye and label it

Answer 1

A = Optic Nerve

B = Retina

C = Lens (Pupil in front)

D = Cornea

E = Iris (Ciliary Muscles Behind)

Question 2

What different ways can fitness be mesured? Name 3

Answer 2

Stamina, streth, flexibility, agility, speed, cardiovascular efficency

Question 3

What is the difference between fitness and health?

Answer 3

Physical fitness is the ability to do physical activity, health is the amount someone is free from disease

Question 4

Name 3 factors that can cause heart disease?

Answer 4

High blood pressure, smoking, too much saturated fat/salt

Question 5

What factors can increase blood pressure?

Answer 5

Smoking, too much salt, overweight, stress, too regular alcohol/saturated fat

Question 6

3 problems associated with high blood pressure?

Answer 6

Heart attack, stroke, kidney damage

Question 7

How smoking increases blood pressure?

Answer 7

Carbon monoxide combines with hemoglobin in the red blood cells and prevents from carrying as much oxygen. The heart beats faster to compensate. This puts a strain on the heart. Nicotine increases heart rate.

Question 8

How saturated fat increases blood pressure?

Answer 8

The liver makes cholesterol from saturated fat. Cholesterol is carried in the blood and may be deposited in artery walls. These deposits narrow the arteries and restrict blood-flow. The blood pressure increases to force blood through the narrower gap.

Question 9

How is blood transported around the body at the correct pressure?

Answer 9

Each time the heart beats it’s muscles contract. This pushes the blood out into the arteries at the correct pressure so it reaches all parts of the body.

Question 10

A person has a blood pressure measurement of 120/80 mmHg - what does this mean?

Answer 10

120 refers to the pressure in the arteries when the heart contracts (systolic pressure), and the 80 refers to the pressure in the arteries when the heart relaxes (diastolic pressure)

Question 11

What happens to systolic pressure during excersize?

Answer 11

It goes up, then returns to normal afterwards.

Question 12

Why do you need to eat, carbohydrates, fat, proteins, iron, general vitamins and minerals, vitamin c, fibre, water

Answer 12

To give energy, to give energy, for growth and repair, to make haemoglobin, to help with protection from disease and proper functioning of bodily activities such as with iron, to prevent scurvy, to prevent consipation, to prevent dehydration.

Question 13

why do some people in developing (2) and developed (1) countries not get enough protein?

Answer 13

Developing: Overpopulation, limited investment in agricultural techniques so less food produced Developed : low self esteem and think they will look better.

Question 14

Why are second class proteins generally not as good - eating more of these is also a reason why developing countries do not get enough protein

Answer 14

Most animal proteins provide all the essential amino acids where is individual plant proteins do not - vegetarians should ear a wide variety of plant proteins.

Question 15

What happens if children do not get enough protein?

Answer 15

They will suffer from deficiency diseases from stunted growth, and the body will not be able to fight infection very well

Question 16

What is the difference between infectious and non infectious diseases? give 3 examples of what may cause the latter

Answer 16

Infectious disease is caused by microorganisms to invade your body. These harmful microorganisms are parasites. Noninfectious diseases on not caused by parasites, and could be caused by and mineral deficiency a body disorder, vitamin deficency, or genetic inheritance

Question 17

What is a parasite and a host?

Answer 17

Parasites are a microorganism that invades an animal body, gaining nutrients and shelter from the host.

Question 18

What is the difference between a malignant and benign tumor?

Answer 18

A benign tumor does not spread to other parts of the body, and can be cut out. A malignant tumor does spread to other parts of the body and is more agressive.

Question 19

Name 3 ways to reduce chances of cancer

Answer 19

Not being overwheight, sunbathing very little, or not at all. Eating little red meat and processed food, eating plenty of fresh fruit and vegtables, taking regular excersize, avoiding drinking too much alcohol

Question 20

What causes infectious diseases, describe it?

Answer 20

Parasitic microorganisms called pathogens, which may damage cells and release toxins.

Question 21

Name four types of pathogens, and diseases caused by them

Answer 21

Fungi: Athletes Foot, Bacteria: Cholera, Viruses: Flu

Question 22

How do Malaria vectors spread disease - how does knowing this help?

Answer 22

Malaria is caused by a parasite which is spread by female mosquitos, which when they bite someone can be spread. This makes both humans and mosquitos the host. Knowing this allows for the use of control tactics such as mosquito nets, draining areas of stagnant water and using insecticides.

Question 23

What is the incidence of a disease and what two factors affect it? Describe these factors

Answer 23

The incidence is the rate at which new cases occur in a population each year, per an amount of people. This can be affected by climate: In places where it is warm or hot, vectors may multiply rapidly, and socio-economic factors: no clean drinking water, for example

Question 24

What are antibiotics?

Answer 24

Chemicals to kill or prevent the growth of harmful bacteria or fungi

Question 25

Why are antibiotics not the same as antivirals?

Answer 25

Viruses do not grow, so have no metabolic reactions to be prevented. Antivirals simply inhibit the growth of the virus in the host.

Question 26

Why do antibiotics have to be used carefully?

Answer 26

In case of a resistant strain developing, the whole course must be finished.

Question 27

Describe the body defenses against becoming ill

Answer 27

The skin- stops microbes penetrating into body, and glands produce oils to kill microbes. Blood clotting - the blood contains platelets, and a protein called fibrin, which close the wound quickly. Nasal hairs keep out larger microorganisms, and mucus traps them. Stomach/hydrochloric acid kills harmful microorganisms in food

Question 28

Describe how white blood cells protect against infection.

Answer 28

They engulf pathogens and destroy them, produce antibodies to destroy pathogens - these fit to antigens, chemicals foreign to the body, and then makes copies of the antibody to neutralize the antigen and they produce antitoxins to neutralize toxins produced by pathogens

Question 29

Describe passive and active immunity

Answer 29

If antibodies have been produced against an antigen, some of the white blood cells remain. If the same pathogen infects again, these cells reproduce rapidly and the pathogen is destroyed. This is active immunity. Passive is when these antibodies are instead injected which the body then remembers

Question 30

Briefly describe the 3 stages of drug testing

Answer 30

Tested using computer models and grown human cells - Tested on animals - Tested on clinical trials. These trials often mean many drugs cannot pass the tests, which is why development is expensive and tim-consuming

Question 31

Describe double blind trials

Answer 31

These aim to avoid a patient feeling better just because they think medicine has been taken - the placebo effect. Some volunteers are given placebo, or 'fake' versions of the drug.

Question 32

Describe vaccination

Answer 32

Vaccination involves putting an inactive form of pathogen into the body, which act as antigens. These stimulate white blood cells to produce antibodies which can then produce rapidly later if a person is infected.

Question 33

Give 5 types of drug

Answer 33

Depressant, Hallucinogen, painkiller,performance enhancer, stimulant

Question 34

Give 3 examples of a depressant and its detailed effect on the body

Answer 34

Alcohol, solvents and tremazepam, Depressants stop neurons sending nerve impulses, they bind to the receptor molecules it needs to respond to neurotransmitter molecules slowing down brain activity

Question 35

Give an example of a hallucinogenic and its affect on the body

Answer 35

Alters what is heard or seen, LSD

Question 36

Give two examples of painkillers and the effect on the body

Answer 36

Blocks nerve impulses, asprin, paracetamol

Question 37

Give an exampleof a performance enhancer, and is effect on the body

Answer 37

Improves muscle development, anabolic steroids

Question 38

Give 3 examples of a stimulant and a detailed description of the effect on the body

Answer 38

Cause more neurotransmitter molecules to diffuse across the synapse increasing brain activity, nicotine caffeine ecstasy

Question 39

Why is smoking during pregnancy dangerous?

Answer 39

Reduces amount of oxygen to fetus, increased risk of low birth weight in babies.

Question 40

Give 3 short term effects of alcohol use

Answer 40

Sleepiness, impaired judgement, blurred vision, slurred speech, increased blood flow to skin

Question 41

Give a long term effect of alcohol

Answer 41

Damage to liver and brain

Question 42

How does alcohol damage the liver?

Answer 42

the liver has enzymes that break down alchol, but the products of the reaction are toxic, damaging the liver over time

Question 43

what is in the central nervous system of a human (CNS)

Answer 43

brain and spinal chord

Question 44

Describe the cornea and its function

Answer 44

Front part of touch outer coat, convex and transparant. Refracts light as it enters eye

Question 45

Describe iris and function

Answer 45

pigmented so light cannot pass through.Its muscles contract and relax to control how much light enters pupil

Question 46

Describe the lens and function

Answer 46

Transparent, flexible disc behind the iris, focuses light onto the retina

Question 47

Describe retina and function

Answer 47

The lining at the back of the eye containing two types of photoreceptor cells - rods - sensitive to dim light and black and white - cones - sensitive to colour,

Question 48

Describe optic nerve and function

Answer 48

Bundle of sensory neurons at the back of the eye, carries impulses from eye to brain

Question 49

Advantages/Disadvantages of Binocular vision over monoclular

Answer 49

Better depth perception, worse field of view. Birds and lizards have monocular useful for spotting predators. Because human eyes sit side by side, each eye captures a slightly different view

Question 50

Where does the eye focus on the retina for short and long sight?

Answer 50

Short: Focuses in front of retina Long: Behind retina

Question 51

why does colour blindness occur

Answer 51

People withy colour blindness have a lack of receptors in the retina, or defects in them

Question 52

What is the function of sensory neurones

Answer 52

to carry signals to spinal chord and brain

Question 53

what is the function of the relay neurones?

Answer 53

to carry messages from one part of the CNS to another

Question 54

what is the function of motor neurones?

Answer 54

to carry signals from the CNS to the effectors

Question 55

Label the nerve diagram 1, 2, 3, 5, 9 

Answer 55

1 - Cell Membrane 2 - Cytoplasm 3 - Axon 9 - Nuleus 5- Nerve Ending

Question 56

Describe what happens at a synapse relating to neurons

Answer 56

one neuron releases a chemical into the gap, the signal diffuses across the gap and makes the next neuron transmit an electrical signal

Question 57

Describe a reflex action, two examples and the order after it

Answer 57

Reflex actions are actions that do not need the involvement of the brain, very quick responses. This could be a muscle contracting, a gland secreting a hormone. A STIMULUS is detected by a RECEPTOR. A SENSORY NEURON sends a signal to the RELAY NEURON, then a MOTOR NEURON sends a signal to an EFFECTOR which produces a response

Question 58

Describe Problem with short/long sighted and how to correct it

Answer 58

short: eyeball too elongated, distance between lens and retina too great, Corrected by concave lens. Long: loss of elasticity in lens, corrected by convex lens

Question 59

What is homeostasis and name 3 substances that must be controlled in the body

Answer 59

Conditions in the body are controlled to provide a constant internal environment. This is called homeostasis. The conditions that must be controlled include body temperature, water content, carbon dioxide level and blood sugar level.

Question 60

Why are carbon dioxide levels controlled in homeostasis

Answer 60

Carbon dioxide is a waste product of respiration.Carbon dioxide forms an acidic solution when it dissolves in water. Carbon dioxide levels must be controlled to avoid the blood becoming too acidic or too alkaline.

Question 61

Why and how (3 ways) is Body temperature controlled in homeostasis

Answer 61

This is controlled to maintain the temperature at which enzymes work best, which is 37 °C. Body temperature can be controlled by: sweating shivering altering blood flow to the skin.

Question 62

Why and how (3 ways) is The body’s water content controlled in homeostasis

Answer 62

This is controlled (to protect cells) by stopping too much water from entering or leaving them. Water content can be controlled by altering water loss from the: lungs when we exhale skin by sweating body, in urine produced by the kidneys.

Question 63

Why are Extremes of body temperature dangerous?

Answer 63

low temperatures can cause hypothermia and death if untreated high temperatures can cause dehydration, heat stroke and death if untreated.

Question 64

How can heat be gained by the body? (3 ways)

Answer 64

respiration, shivering, or by reducing the blood flow to the skin.

Question 65

How can heat be lost in the body? (2 ways)

Answer 65

by reducing the blood flow to the skin or by sweating. Sweating increases heat loss by evaporation.

Question 66

Describe in detail why your face goes red or pale in high or low temperatures

Answer 66

The blood vessels supplying blood to the skin can dilate or swell. This is called vasodilation. It causes more heat to be carried by the blood to the skin, where it can be lost to the surroundings. Blood vessels can shrink down again. This is called vasoconstriction. It reduces heat loss from the skin once the body’s temperature has returned to normal.

Question 67

Describe in a little detail, with regards to the brain, how the body controls temprature

Answer 67

The body’s temperature is monitored by a part of the brain called the hypothalamus. If you are too hot or too cold, it sends nerve impulses to the skin.

Question 68

Where is the pancreas and what does it do?

Answer 68

Deep in the back of the stomach, sitting across the back of the abdomen. It produces insulin which helps to control the body's blood sugar levels

Question 69

What Happens to the pancreas and liver when the blood glucose is too high or too low?

Answer 69

**_Too high_** insulin is secreted into the blood, the liver converts glucose into glycogen and the glucose level goes down It is the oppost for too low - the processes do not happen and less glucose is absorbed by the body cells

Question 70

Describe type 1 diabetes, who it mainly affects, how it works, and how it is controlled.

Answer 70

Children and teenagers, or Adults under the age of 40. The pancreas stops making enough insulin, Injections of insulin for life and an appropriate diet.

Question 71

Describe type 2 diabetes, who it mainly affects, how it is controlled, and how it works.

Answer 71

Adults, normally over the age of 40 (there is a greater risk in those who have poor diets and/or are overweight). The body no longer responds to its insulin. The body no longer responds to its insulin. Exercise and appropriate diet.

Question 72

What is a tropism and what are the two main types

Answer 72

A 'tropism' is a growth in response to a stimulus. ## Footnote positive tropisms – the plant grows towards the stimulus negative tropisms – the plant grows away from the stimulus.

Question 73

Describe phototropism and geotropism, as well as which parts of the plant have which one positevely.

Answer 73

Phototropism is a tropism where the stimulus is light. A geotropism is a tropism where the stimulus is gravity. Shoot: positive phototropism (grow towards the light) negative geotropism (grow against the force of gravity) Roots: Opposite

Question 74

How are tropisms controlled, and what is the thing that controlls them

Answer 74

Tropisms are controlled by plant hormones called auxins. These water-soluble chemicals move through the plant in solution.Auxin is a plant hormone produced in the stem tips and roots, which controls the direction of growth.

Question 75

Breifly describe three ways can plant hormones be used

Answer 75

**Weed killers** (Selective weed killers attack some plants but not others), **Rooting powder**, **Controlling fruit ripening** (useful for delaying ripening during transport or when fruit is displayed in shops), **Dormancy** (stops seeds germinating until conditions are ideal for growth).

Question 76

Describe where auxins are found, and how they affect the plant

Answer 76

Auxins are mostly made in the tips of the shoots and roots, and can diffuse to other parts of the plant. Auxins change the rate of elongation in plant cells, controlling how long they become. Shoots and roots respond differently to high concentrations of auxins: cells in shoots grow more cells in roots grow less. In a shoot and root, the **shaded side contains more auxin.**

Question 77

What chromosomes are on male and female mammals?

Answer 77

Male mammals carry XY sex chromosomes - female mammals carry XX sex chromosomes.

Question 78

How are inherited disorders caused?

Answer 78

By faulty genes on chromosomes, which are mostly (but not always) domiant alleles

Question 79

What are Alleles and what are the two main types?

Answer 79

Different versions of a gene are called alleles, and these alleles can be dominant or recessive.

Question 80

Give 3 examples of an inherited charactaristic

Answer 80

the shape of the earlobes eye colour nose shape.

Question 81

Give 3 characteristics that are both enviromental and inherited

Answer 81

intelligence, body mass and heigh

Question 82

What does DNA (Briefly!) do?

Answer 82

Carrys the genetic code that determines the characteristics of a living thing.

Question 83

What is a gene and what does it briefly do?

Answer 83

A gene is a short section of DNA. Each gene codes for a specific protein by specifying the order in which amino acids must be joined together.

Question 84

What are chromosones made from?

Answer 84

Long DNA molecules.

Question 85

How many chromosones do humans have?

Answer 85

46, 23 pairs

Question 86

What are gametes and what is unusual about their chromosones?

Answer 86

Gametes are sex cells. The male gametes are the sperm, and the female gametes are the eggs. Gametes contain half the number of chromosomes as body cells do. They contain half the genetic information that body cells do.

Question 87

What are dominant and ressesive alleles?

Answer 87

the characteristic controlled by a dominant allele develops if the allele is present on one or both chromosomes in a pair the characteristic controlled by a recessive allele develops only if the allele is present on both chromosomes in a pair.

Question 88

What dos it mean if an indivual has two identical alleles, two different alleles

Answer 88

Homozygous, Heterozygous

Question 89

If somebody was to have blue eyes, through a combination of alleles, what would that be?

Answer 89

The phenotype, the characteristics expressed by an individual.

Question 90

What is a genotype?

Answer 90

The written down combination of alleles - Tr or Ye for example

Question 91

Name 3 inherited disorders

Answer 91

red-green colour blindness sickle cell anaemia cystic fibrosis.

Question 92

What does a gentic diagram look like?

Answer 92

This.