B2

Question 1

Name the 4 components of blood and their function

Answer 1

Red blood cell - transport oxygen
White blood cell - defend against pathogens
Platelets - clot the blood
Plasma - carries many substances (glucose, hormones)

Question 2

Define carcinogen

Answer 2

A substance/chemical that causes cancer
E.g. chemicals in cigarette smoke

Question 3

Pacemaker

Answer 3

A group of cells that control the resting heart rate

Question 4

What’s the difference of the left ventricle and right ventricle?

Answer 4

Left ventricle has to pump blood at a high pressure to it can reach all body cells (due to thick, muscular walls)
Right ventricle only has to pump blood to the lungs

Question 5

What’s the structure of an artery and why?

Answer 5

Thick layers of muscle - maintain high pressure
Elastic fibers - spring back (withstand pressure)
Narrow lumen - strong thick walls

Question 6

What are the functions of statins and the advantages/disadvantages?

Answer 6

Definition - drugs to lower cholesterol levels in the blood, by reducing the amount produced in the liver
Advantage - prevent development of heart disease
Disadvantage - side-effects, long term treatment

Question 7

What are the functions of stents and the advantages/disadvantages?

Answer 7

Definition - mechanical device to stretch narrow arteries, restoring blood flow
Advantage - long term benefit, drugs (statins) are less effective
Disadvantage - risk of infection in surgery

Question 8

What are the functions of heart transplants and the advantages/disadvantages?

Answer 8

Definition - entire organ is replaced with another from a donor
Advantage - can treat complete heart failure
Disadvantage - requires major surgery which involves lots of recovery

Question 9

What’s the equation for cardiac output

Answer 9

heart rate X stroke volume

Question 10

Define stroke volume

Answer 10

A measure of the volume of blood pumped from the heart each contraction

Question 11

Oxyhaemoglobin

Answer 11

haemoglobin + oxygen

Question 12

What is coronary heart disease and the symptoms?

Answer 12

Blockage in the coronary arteries
Symptoms:
Chest pain, heart attack, heart failure

Question 13

Name 3 factors that increase the risk of CHD

Answer 13

Diet - high fat = high cholesterol
Smoking - reduces oxygen
Stress - high blood pressure

Question 14

Describe the difference between a benign and malignant tumour

Answer 14

Benign:
Remains in one place
Doesn’t invade other tissues in the body
Not cancerous
Malignant:
Spreads to other parts of the body when cells break off and travel in the bloodstream to form secondary tumours
Cancerous
Can’t be removed

Question 15

How does smoking tobacco affect adults and unborn babies?

Answer 15

Adult - can cause lung disease, cardiovascular disease, cancer
Unborn babies - can cause low birth weight and premature birth

Question 16

What’s the function of valves?

Answer 16

Prevent backflow of blood between chambers and vessels

Question 17

Which blood vessel transports blood AWAY from the heart?

Answer 17

Artery

Question 18

Which blood vessel transports blood TO the heart?

Answer 18

Vein

Question 19

What’s the function of blood in the circulatory system?

Answer 19

Transport oxygen and nutrients to tissues

Question 20

What’s the function of blood vessels in the circulatory system?

Answer 20

Holds/ transports blood

Question 21

What’s the function of pacemakers?

Answer 21

Produce small electrical impulse in the right atrium to keep a regular heartbeat

Question 22

What’s the function of the heart in the circulatory system?

Answer 22

Pumps blood to move it through vessels

Question 23

Name adaptations of a leaf and it’s function

Answer 23

Flat and thin - reduces distance for diffusion
Large surface area - maximum area to absorb sunlight and carbon dioxide for photosynthesis

Question 24

Name the function of a xylem

Answer 24

Transport water and minerals to leaves

Question 25

Name the function of a phloem

Answer 25

Transport glucose and other nutrients around the plant

Question 26

Describe the structure of a xylem

Answer 26

Thick walls strengthened with lignin MOVEMENT: ROOTS - LEAF

Question 27

Describe the structure of a phloem

Answer 27

Thin cell walls with live cells and cellulose MOVEMENT ALL AROUND PLANT

Question 28

What's the function of guard cells?

Answer 28

To open and close the stomata, controlling the rate of gas exchange in the leaf (positioned in pairs, underside of the leaf)

Question 29

Define transpiration

Answer 29

The loss of water by evaporation and diffusion from leaves

Question 30

Define translocation

Answer 30

Food produced in photosynthesis is transported from the leaves to the growing regions of the plant (OCCURS IN PHLOEM)

Question 31

Name 4 factors affecting rate of transpiration

Answer 31

Light intensity Temperature Humidity Wind speed

Question 32

What does BENEDICT'S TEST test for?

Answer 32

Sugar (blue - brick red ; needs heating up)

Question 33

What does IODINE test for?

Answer 33

Starch (black when present)

Question 34

What does BIURET'S TEST test for?

Answer 34

Protein (blue - purple)

Question 35

What do digestive enzymes do and why?

Answer 35

Break down big molecules. WHY? They are too big to pass through the walls of the digestive system so they can't be absorbed into the bloodstream.

Question 36

Where is AMYLASE made?

Answer 36

Salivary glands Pancreas Small intestine

Question 37

Where is PROTEASE made?

Answer 37

Stomach Pancreas Small intestine

Question 38

Where is LIPASE made?

Answer 38

Pancreas Small intestine

Question 39

What does amylase do?

Answer 39

Convert carbohydrates into simple sugars

Question 40

What does protease do?

Answer 40

Convert proteins into amino acids

Question 41

What does lipase do?

Answer 41

Convert lipids into glycerol AND fatty acids

Question 42

What is the role of BILE?

Answer 42

Neutralise stomach acid and emulsify fats

Question 43

Where is bile produced and stored?

Answer 43

Produced in the liver Stored in the gall bladder then released into the small intestine

Question 44

What is a tissue?

Answer 44

A group of similar cells working together to carry out a particular function

Question 45

What is an organ?

Answer 45

A group of tissues working together to carry out a particular function

Question 46

What is an organ system and give an example.

Answer 46

A group of organs working together to carry out a particular function. DIGESTIVE SYSTEM

Question 47

Why can enzymes be described as biological catalysts?

Answer 47

They speed up chemical reactions without being used up during the process.

Question 48

What is the difference between the 'lock and key' theory and the 'induced fit' theory for enzymes?

Answer 48

LOCK AND KEY: The substrate has to fit perfectly into the active site. INDUCED FIT: The active site is complementary to the substrate.

Question 49

Why is a catalyst used instead of temperature to speed up the rate of a reaction?

Answer 49

Too much temperature can damage cells and it requires lots of energy.

Question 50

What does it mean when an enzyme has been denatured?

Answer 50

The shape (active site) has changed so it can no longer bind to the substrate and perform the function.

Question 51

How does an enzyme denature?

Answer 51

Extreme heat or wrong pH levels

Question 52

Why is the circulatory system in humans described as a 'double circulatory system'?

Answer 52

Because blood passes through the heart twice during each complete circuit of the body.

Question 53

Name the 4 chambers of the heart.

Answer 53

right atrium right ventricle left atrium left ventricle

Question 54

How are arteries adapted to carry blood away from the heart?

Answer 54

Strong, elastic, thick muscular walls to withstand the high pressure of the blood AWAY from the heart.

Question 55

Why do red blood cells not have a nucleus?

Answer 55

To create more space for haemoglobin

Question 56

List the tissues that make up a leaf.

Answer 56

Upper epidermal Palisade mesophyll Spongy mesophyll Lower epidermal Xylem Phloem

Question 57

How is the structure of the upper epidermal tissue in a leaf related to its function?

Answer 57

It is transparent which means light can shine through to the palisade mesophyll where photosynthesis happens. It has a waxy cuticle which helps to reduce water loss by evaporation.

Question 58

What do you use to measure the rate of transpiration?

Answer 58

Potometer - count the rate of bubbles.

Question 59

Name 4 risk factors that increase the chance of cancer

Answer 59

Smoking Obesity UV exposure Viral infection

Question 60

What are the 4 effects of liver failure on the human body?

Answer 60

1. No bile made in the liver - fats/lipids are not emulsified - may lose weight 2. Lactic acid can not be broken down - oxygen debt is higher - lactic acid is a poison: muscle pain 3. Proteins/amino acids are not broken down - amino acids aren't made into urea 4. Liver doesn't break down toxins - toxins (alcohol) accumulate - poisoning