Predicted paper mistakes

Question 1

Specialised cell

Answer 1

A cell that differentiates to carry out a specific function

Question 2

Substances travelling from respiring cells into the blood

Answer 2

Carbon dioxide
Lactic acid
Water

Question 3

How does glucose move from the blood into muscle cells?

Answer 3

Glucose moves from the blood into muscle cells by diffusion, with a higher concentration of glucose in the blood than in the muscle cells

Question 4

Reasons for negative percentage changes of parsnip cylinder in solution

Answer 4

Higher concentration of water molecules inside the cell than outside, so water moves out of the cell/cylinders into the solution by osmosis

Question 5

How does the surface area of plant tissue affect osmosis?

Answer 5

The greater the surface area of the plant tissue, the more water moved across the cells and cylinder/solution

Question 6

How to calculate the rate of respiration

Answer 6

By measuring the volume of CO2 produced(in a measuring cylinder/gas syringe) in a certain time period(stopwatch)

Question 7

Why are yeast cells important to the brewing and baking industries?

Answer 7

Baking produces CO2 which makes bread rise.
Brewing produces ethanol, with CO2 making alcohol drinks fizzy and ethanol the alcohol in alcoholic drinks

Question 8

Protease enzymes

Answer 8

Catalyse breakdown of proteins into amino acids

Question 9

Components of blood carried in the blood plasma

Answer 9

Red blood cells
Platelets

Question 10

What happens to an enzyme of the temperature is too high?

Answer 10

If a temperature is too high, some of the bonds holding the enzyme break, changing the shape of the enzyme’s active site so it doesn’t work

Question 11

Structure of lungs

Answer 11

1) The thorax is the top part of the body, separated from the lower part of the body by the diaphragm.
2) The lungs are protected by the ribcage.
3) The air you breathe in goes through the trachea, splitting into two tubes called bronchi(each one is a bronchus), one going to each lung.
4) The bronchi split into progressively smaller tubes called bronchioles.
5) The bronchioles finally end at small bags called alveoli where gas exchange takes place.

Question 12

Benign tumour

Answer 12

A mass of abnormal cells not invading other parts of the body

Question 13

Why does increasing air movement around a plant’s leaves increase the rate of transpiration?

Answer 13

This increases the rate of diffusion, with water vapour diffusing from the plant’s leaves into the surrounding air, as the water vapour surrounding the leaf is swept away

Question 14

How mosquito nets help to prevent the spread of malaria

Answer 14

Mosquito nets stop people being infected with the protist causing malaria(stops people being bitten by mosquitoes)

Question 15

Muscle fatigue

Answer 15

Muscle fatigue is where the muscles tire and can’t contract efficiently, after large periods of exercise.

Question 16

How do plants make proteins?

Answer 16

Glucose is combined with nitrate ions from the soil to make amino acids, made into proteins

Question 17

Exchange surface for animals adapted

Answer 17

Thin membrane
Large surface area
Ventilation
Lots of blood cells

Question 18

Exchange in plants

Answer 18

The surface of the leaf is flattened, for more gas exchange by diffusion.
Guard cells open and close the stomata for gas exchange and water loss

Question 19

Exchange in fish

Answer 19

Fish have a large surface area for gas exchange(gills). Water enters the fish through the mouth and goes out through the gills. The oxygen’s transported from the water to the blood by diffusion. CO2 diffuses from the nlood to the water. Each gill has gill filaments for a large surface area for the gills.
Lamellae cover each gill fillament to firther increase the surface area for gas exchange.
Capillaries provide a good blood supply to help with diffusion.

Question 20

Why are malignant tumours more dangerous than benign tumours

Answer 20

Because malignant tumpurs can spread and invade neighbouring tissues before breaking off and spreading to other parts of the body forming secondary tumours

Question 21

Internal conditions your body needs to keepconstant to survive

Answer 21

Body temperature
Water content levels
Blood sugar levels

Question 22

Why is it important for the body temperature to be maintained at a certain level?

Answer 22

So the cells and enzymes have the right conditions to function

Question 23

Are gametes genetically identical to each other?

Answer 23

No- never

Question 24

How does draining peat bogs to produce compost contribute to global warming?

Answer 24

This causes peat bogs to decompose, releasing CO2, which increases global warming

Question 25

How does global warming lead to the destruction of the low-lying habitats?

Answer 25

Global war,ing causes water to expand, causing rising sea levels, leading to flooding of low-lying land, so destruction of habitats

Question 26

Disadvantages of embryonic screening

Answer 26

Expensive
Risk of damaging embryo
Pregnancy termination

Question 27

Dominant allele

Answer 27

Only one copy of the allele is enough for it t9 be expressed

Question 28

Why are predator-prey cycles out of phase?

Answer 28

It takes a while for one population to respond to changes in another

Question 29

How will injecting FSH and LH help a woman hecome pregnant?

Answer 29

FSH causes several eggs to mature in the ovary, then LH causes release of the egg, so more eggs are present, therefore a higher probability/chance of fertilisation

Question 30

Main difference in cell division to form sperm cells compared with cell division to form liver cells

Answer 30

Meiosis forms sperm and mitosis forms liver cells

Question 31

Why polar bears find it harder to catch seals in autumn than in spring?

Answer 31

More competition between polar bears
All/most seals in the sea