General

Question 1

Test for protein

Answer 1

Biuret test. If protein is present the colour of the solution will go from blue to purple

Question 2

State the advantages of cuttings

Answer 2

• Genetically identical plants so share positive characteristics of original plant
• Quick
• Can grow species that aren’t originally suited to cuttings
• Can be done all year round
• Can store plants for later use
• Easily used for genetic modification of plants

Question 3

Test for starch

Answer 3

Iodine goes from orange to blue-black

Question 4

Test for lipids

Answer 4

Emulsion test - add ethanol, then water, milky white emulsion will form

Question 5

Test for glucose

Answer 5

Benedict’s solution - blue to
• green = low concentration
• Yellow = medium concentration
• Brick red = high concentration

Question 6

Role of the enzyme amylase

Answer 6

Converts starch into maltose

Question 7

Role of the enzyme maltase

Answer 7

Converts maltose into glucose

Question 8

Role of the enzyme protease

Answer 8

Converts proteins into amino acids

Question 9

Role of the enzyme lipase

Answer 9

Converts lipids into glycerol and fatty acids

Question 10

What is the role of bile?

Answer 10

Bile neutralises stomach acid and emulsifies fat

Question 11

Where is bile produced, stored and released?

Answer 11

• Produced in the liver
• Stored in the gall bladder
• Released into the small intestine

Question 12

Describe the path of food through the alimentary canal

Answer 12

Mouth → Stomach → Small intestine → Large intestine → Rectum → Anus

Question 13

What is the role of the pancreas?

Answer 13

Produces enzymes like protease, amylase and lipase and releases them into the small intestine

Question 14

Reflex arc (4 marker)

Answer 14

• Sensory organ (receptor) detects stimulus
• Sends impulse down sensory neuron
• Impulse reaches CNS and is passed on to relay neuron
• Relay neuron passes impulse to motor neuron
• Motor neuron passes impulse to effector (muscle)
• Effector carries out the action

Question 15

Explain how this evolutionary change was brought about by natural selection

Answer 15

• Variation in the population
• Mutation in genotype causes a change in phenotype
• Advantageous change increases survival chances
• Characteristic selected by natural selection
• Favourable allele is passed on to offspring through reproduction

Question 16

What is the function of the semi-lunar valves?

Answer 16

To prevent backflow of blood from the pulmonary artery back into the right ventricle and from aorta back into the left ventricle

Question 17

What is the purpose of the atrioventricular valves?

Answer 17

To separate the atrium and ventricle

Question 18

What are the names of the left and right atrioventricular valves?

Answer 18

Left - Bicuspid
Right - Tricuspid

Question 19

role of the xylem

Answer 19

transport water and mineral salts up the shoot to the leaves

Question 20

role of phloem

Answer 20

transport sugars from leaves where they are produced to other parts of the plant to use in respiration

Question 21

role of platelets

Answer 21

in the blood. Used for blood clotting.

Question 22

what is a pathogen

Answer 22

a microorganism that causes disease

Question 23

two types of white blood cell

Answer 23

lymphocyte phagocyte

Question 24

what do phagocytes do

Answer 24

detect pathogens, engulf them and then digest them.

Question 25

what do lymphocytes do

Answer 25

produce proteins called antibodies that are specific to the pathogens antigen. Fire out the antibodies onto other pathogens so the phagocyte can destroy them.

Question 26

what does hepatic mean

Answer 26

the blood vessel has to do with the liver

Question 27

what does renal mean

Answer 27

the blood vessel has to do with the kidneys

Question 28

source and effects of adrenaline

Answer 28

Source - adrenal glands on top of kidneys Effect - raises heart rate, blood flow to muscles and blood sugar levels

Question 29

source, role and effects of insulin

Answer 29

Source - pancreas Effect - stimulates liver to turn glucose into glycogen for storing

Question 30

source, role and effects of testosterone

Answer 30

Source - testes Effect - promotes male secondary sexual characteristics

Question 31

source, role and effects of progesterone

Answer 31

Source - ovaries Effect - maintains the uterus lining

Question 32

source, role and effects of oestrogen

Answer 32

Source - ovaries Effect - main female sex hormone. Controls the menstrual cycle and promotes secondary sexual characteristics.

Question 33

what are the complementary bases in DNA

Answer 33

cytosine and guanine. Adenine and thymine

Question 34

what does asexual reproduction mean and what does it involve

Answer 34

involves only one parent. Involves mitosis

Question 35

what does sexual reproduction mean and what does it involve

Answer 35

the fusion of male and female gametes. Involves meiosis

Question 36

Name the carbohydrate in milk that is used to make yoghurt

Answer 36

Lactose

Question 37

Name the bacteria added to milk to make yoghurt

Answer 37

Lactobacillus

Question 38

What does M in MRS GREN stand for?

Answer 38

M = Movement – Living things can move parts of their bodies.

Question 39

What does R (first R) in MRS GREN stand for?

Answer 39

R = Respiration – Living things release energy from food (usually using oxygen).

Question 40

What does S in MRS GREN stand for?

Answer 40

S = Sensitivity – Living things detect and respond to changes in their environment.

Question 41

What does G in MRS GREN stand for?

Answer 41

G = Growth – Living things increase in size or mass.

Question 42

What does R (second R) in MRS GREN stand for?

Answer 42

R = Reproduction – Living things make more of their own kind.

Question 43

What does E in MRS GREN stand for?

Answer 43

E = Excretion – Living things remove waste products from the body.

Question 44

What does N in MRS GREN stand for?

Answer 44

N = Nutrition – Living things take in and use food.

Question 45

What is the cell wall of fungi made of?

Answer 45

Chitin – Unlike plants (which have cellulose), fungi have cell walls made of chitin.

Question 46

What is it called when an enzyme and a substrate are joined together?

Answer 46

Enzyme-substrate complex – Formed when the substrate fits into the enzyme’s active site.

Question 47

How can you investigate how fast a substrate disappears using amylase?

Answer 47

Use iodine to test for starch. Mix amylase and starch in a water bath. Sample every 10 sec and drop onto iodine. When it no longer turns blue-black, starch is gone. Repeat at different temps/pH to test enzyme activity.

Question 48

How do you calculate the surface area of a cube?

Answer 48

Area of one face = side², then multiply by 6: Surface Area = 6 × side².

Question 49

How is the villus adapted for absorption in the small intestine?

Answer 49

Long length, large surface area (villi + microvilli), thin wall (1 cell thick), good blood supply, and lacteal for absorbing fats.

Question 50

What happens when you're too hot?

Answer 50

Lots of sweat is produced. It evaporates and transfers energy from skin to environment, cooling you down.

Question 51

What is vasodilation?

Answer 51

When blood vessels widen, increasing blood flow near the skin to release more heat.

Question 52

What happens to body hair when you're too hot?

Answer 52

Hairs lie flat so they don’t trap heat.

Question 53

What happens when you're too cold?

Answer 53

Very little sweat is produced. Blood vessels constrict (vasoconstriction), reducing blood flow near the skin and heat loss.

Question 54

What is vasoconstriction?

Answer 54

Narrowing of blood vessels to reduce heat loss through the skin.

Question 55

Why do you shiver when cold?

Answer 55

Shivering increases your rate of respiration, which transfers energy to warm the body.

Question 56

What happens to body hair when you're too cold?

Answer 56

Hairs stand up to trap an insulating layer of air to keep you warm.