Test Paper Qs

Question 1

Palisade cells have more chloroplasts than spongy mesophyll cells. Explain why. (1)

Answer 1

So they can absorb more sunlight for photosynthesis as they are on the upper surface of the leaf (1).

Question 2

Suggest why using egg donation is a difficult decision for people to make. (3)

Answer 2

The child will have no genetic link to the mother (1) and may want to find their biological mother in the future (1). Donor eggs may have genetic health conditions etc. (1)

Question 3

Explain why a brewer may use temperatures slightly below the optimum temperature of yeast. (1)

Answer 3

It is cheaper as less energy is required (1).

Question 4

Explain why plants do not grow well in water-logged soils. (3)

Answer 4

There is not enough oxygen in the soil for root hair cells to respire (1) and produce energy for active transport of minerals (1).

Question 5

Suggest why it could be an advantage to grow plants in salty soils. (1)

Answer 5

Plants can be grown in more places (1).

Question 6

Suggest how plants are adopted for absorbing water. (2)

Answer 6

They have root hair cells which increase the surface area for water uptake (1). Water moves across a partially permeable membrane in root hair cells by osmosis (1).

Question 7

Transpiration happens more rapidly when the temperature is higher. Explain why. (1)

Answer 7

More enters for water to evaporate (1).

Question 8

Explain one disadvantage of farmers allowing chickens to more freely. (2)

Answer 8

They will lose more energy through heat and respiration (1), meaning less energy is used for growth (1).

Question 9

Describe ways in which xylem cells are different to potato cells. (2)

Answer 9

Xylem cells have no cytoplasm/organelles (1) and they have a thick cell wall (1).

Question 10

Why can fish not breath out of water? (1)

Answer 10

Gills do not work out of water (1).

Question 11

Why must methane in biogas remain above 50%? (2)

Answer 11

Biogas would be explosive otherwise (1) and it is more flammable (1).

Question 12

Suggest why hip joint replacements only last 20 years. (3)

Answer 12

Metal/plastic wears away (1) and the body reject it (1). Also, it does not grow with the body (1).

Question 13

Which bacterium causes cholera? (1)

Answer 13

Vibrio (1)

Question 14

The number of plankton varies throughout the year. Explain why. (1)

Answer 14

Changes in temperature and light intensity (1) as well as food availability (1).

Question 15

Explain why you should not produce spirits at home. (2)

Answer 15

It is illegal (1) as a license is required to produce spirits (1).

Question 16

Suggests the advantage of having some cartilage in the ribcage. (1)

Answer 16

Flexibility/Movement (1)

Question 17

What are some possible consequences of having the amniocentesis test? (3)

Answer 17

Miscarriage - 1 in 2000 chance (1)
Risk of infection (1)
Abortion (1)

Question 18

State the differences between a single and double circulatory system. (3)

Answer 18

Number of heart chambers (1)
Times blood passes through heart (1)
Blood mixing or not (1)

Question 19

How does agglutination occur? (3)

Answer 19

Agglutination is blood clumping (1) and occurs when incompatible blood types mix (1). Antibodies bind with corresponding antigens on red blood cells (1).

Question 20

What is the name of the chemical substance (containing nitrogen) that plants require for respiration and photosynthesis? (1)

Answer 20

Proteins, e.g. enzymes (1)

Question 21

State ways in which farmers use biomass. (3)

Answer 21

Food (1)
Animal food (1)
Building (1)

Question 22

What two substances broken down into ammonia? (2)

Answer 22

Urea (1) and proteins (1)

Question 23

What does breathing rate suggest about the severity of asthma? (2)

Answer 23

Slower breathing rate implies worse asthma (1) as airways are narrower (1).

Question 24

Suggest problems blood might be tested for prior to a blood transfusion.

Answer 24

Anaemia (1)
WBC/RBC (1)
Platelet count (1)
Pathogens (1)
HIV (1)
Haemophilia (1)

Question 25

Suggest ways intensive farming damages the environment. (3)

Answer 25

Fertilisers cause eutrophication (1)
Pesticides kill other organisms - bioaccumulation (1)
Herbicides kill other plants (1)

Question 26

Explain how water is transported from the roots up to the leaves. (2)

Answer 26

Transpiration occurs in leaves (1) causing water to be pulled up through xylem vessels (1).

Question 27

Explain why the stomata cannot remain completely closed. (2)

Answer 27

Needed for gas exchange (1) and cooling from transpiration (1).

Question 28

What are the advantages of gasohol? (2)

Answer 28

Releases no particulates (1) and is a more renewable energy source (1).

Question 29

Explain why lactose sugars need to be broken down. (2)

Answer 29

To prevent them from fermenting in the gut (1) and in order to enter the blood (1).

Question 30

What makes a suitable organ donor? (2)

Answer 30

Tissues match (1) and healthy (1).

Question 31

Why must progesterone levels remain high after fertilisation? (3)

Answer 31

To maintain the uterus lining (1) so the embryo can develop (1). This avoids miscarriage (1).

Question 32

Why should pesticides not be used? (2)

Answer 32

Can kill other organisms through bioaccumulation (1) and pests can become persistent (1).

Question 33

Why do large amounts of bacteria cause the body temperature to rise? (1)

Answer 33

The body responds by raising the temperature to kill bacteria (1).

Question 34

Biofuels can be produced and used without causing a net increase in greenhouse gas levels. Explain how. (2)

Answer 34

Biomass absorb carbon dioxide for photosynthesise during their lifetime (1). This balances the carbon dioxide released when biofuels are burned (1).