BIO p1 Exam Qs

2025 (4)

2025

2025: Explain the difference in the rate of photosynthesis at 40°C compared with the rate of photosynthesis at 10°C (3)

2025: Name blood vessel D (1)

pulmonary vein

2025: Explain why having an increased number of red blood cells is an advantage to an athlete (2)

2025 (4)

2025: Explain why the metabolic rate of a fish is higher when swimming compared with when resting (4)

2025: How is the mouse stimulated to produce cell type A?

• injected with antigens

DO NOT ALLOW INJECTING WITH PATHOGEN

2025: A patient with severe liver disease was given a liver transplant.

The drug containing the monoclonal antibody is given to the patient.

Explain how the monoclonal antibody stops the patient’s white blood cells from attacking the cells of the donor liver (3)

2025: Explain why a person with severe liver disease has difficulty digesting fats (6)

2025: Compare the effectiveness of the antibiotics shown in Figure 11 (4)

2025:

It was not possible for the scientist to count the total number of bacteria per cm3 of culture medium.

The cells were too close together to be counted accurately.

The scientist took 10 samples from the culture medium.

Each sample had a volume of 0.02 cm3.

Describe how the scientist could use the samples to estimate the number of bacteria in 1cm3 of culture medium (2)

2024: A person’s heart stops beating. The person stops breathing. A first aider pushes down on the person’s chest to put pressure on the heart.

Explain why putting pressure on the heart helps the person (2)

• pushes blood

• to get oxygen around the body

DO NOT ACCEPT TO GET OXYGEN TO THE LUNGS

2024: A person is not breathing. A person forces air into their lungs by blowing into their mouth

Describe how forcing air into the person’s lungs helps the person (1)

• provides oxygen (for respiration)

2024: Describe one lifestyle factor that can increase the risk of cardiovascular disease. Do not refer to smoking in your answer. (1)

• poor diet

• lack of exercise

• high alcohol intake

2024 (6)

2024: Describe three features of the alveoli that help maximise gas exchange (3)

2024: Describe one change in structure that occurs when an unspecialised cell differentiates to form a phloem cell (1)

2024: A student said: The bacterium is resistant to antibiotic C

Explain how the results show the student is not correct (2)

2024: Suggest why doctors are concerned about antibiotic resistance (2)

2024 (1)

AIDS

2024: Explain the results for the three leaves (5)

2024: What is meant by a ‘limiting factor’? (1)

2024: Explain the effect of increasing temperature and increasing carbon dioxide concentration on the rate of photosynthesis shown in Figure 7 (4)

2024 (1)

cell membrane

2023 (1)

What are drugs tested for?

• toxicity

• efficacy

• dosage

• side effects

2023: Suggest two reasons why a report making claims about the effects of a chemical/drug may be biased

• so the company may make financial gain

• so that competitors may suffer financial loss

2023: How is the structure of an artery different from the structure of a vein?

artery:

• has thicker muscle tissue

• has thicker elastic tissue

• has a narrower lumen

• does not contain valves

2023: Explain the effect of a partly blocked coronary artery on the human body (6)

2023: How do salmonella bacteria in food cause symptoms of vomiting and diarrhoea? (1)

release toxins

2023 (4)

Culturing microorganisms: aseptic techniques

• disinfect hands + work surface

• sterilise petri dish/ culture medium/ agar before use

• pass inoculating loops through a flame before use

• work near a flame or in a fume cupboard

• tilt lid of petri dish when placing discs on agar (to minimise contact with air/breath)

• secure with tape, but do not seal, the lid of petri dish (to prevent contamination but also to prevent anaerobic respiration creating harmful microorganisms)

2023: Culturing microorganisms: Explain why scientists incubate bacteria at 37^oC but students incubate at 25^oC (3)

2023:

2023: Explain two effects of anaerobic respiration on a person’s body (4)

2023

2023: Describe how scientists make monoclonal antibodies using the cell created when a mouse lymphocyte and a tumour cell combine (3)

The malarial protist is a eukaryotic cell

Describe three ways the structure of the malarial protist is different from the structure of a prokaryotic cell

Do not refer to size in your answer (3)

Explain why the bursting of red blood cells causes tiredness (2)

• less oxygen carried

• less energy released from respiration

2023

DNA replication cannot occur

2023: All of the air had to be removed from the leaf discs before placing them in the beaker. Suggest one reason why (1)

2023: The leaf discs were placed in a beaker of sodium hydrogencarbonate (NaHCO3) solution.

Explain why sodium hydrogencarbonate solution was used instead of water (2)

2023: Explain why the leaf discs moved to the surface of the solution during the investigation (2)

2023: (Use data in table 5 from previous question and figure 10)

Explain the results in Table 5 for blue and green light (4)

2022: Why did the student dry the surface of each potato piece with a paper towel in step 5?

2022: (3)

1. A thin layer of onion epidermis is used

2. Iodine solution is added to the onion epidermis

3. The cover slip is lowered onto the onion epidermis at an angle

1. to help see individual cells / so light can penetrate

2. to stain/see the parts of the cell

→ DO NOT ACCEPT stain the cell

3. to prevent/reduce air bubbles

2022: Give two ways the student could improve the drawing in figure 4 (2)

Two main differences between light and electron microscope

(Electron has)

• higher magnification

• higher resolution

2022 (6)

2022: Describe how mitosis produces two genetically identical cells (4)

2022 (4)

2022: Organism B exchanges gases with the environment directly through its skin

Organism D exchanges gases with the environment using its respiratory system

Explain why organism D requires a respiratory system, but organism B does not (2)

2022: Organisms D and E both keep a constant body temperature

Explain why the metabolic rate of organism D is greater than the metabolic rate of organism E

Use information from table 6 and table 7 (4)

2022:

Suggest one reason for the change in the number of new HIV cases between 2014 and 2018 (1)

2022: Explain how a vaccine for HIV could work to prevent a person developing a HIV infection (4)

2022 (4)

2022: (3)

2021: Function of the coarse focus lens of a microscope (1)

• to focus the image

are plant or animal cells bigger?

plant

2021: Uses of energy released in respiration (2)

any two from:

• movement

• keeping warm

• active transport

• building larger molecules

2021: Explain why the concentration of carbon dioxide in the tube stayed the same between day 0 and day 5 (2)

2021: Suggest why the concentration of carbon dioxide increased between day 5 and day 10 (2)

2021: On day 10, the pond snail died. Explain why the death of the pond snail caused the concentration of carbon dioxide to increase after day 10 (3)

2021: Explain how an enzyme breaks down a substrate

Answer in terms of the ‘lock and key theory’ (3)

• substrate binds to active site of enzyme

• because shape of active site and substrate are complementary

• a chemical reaction occurs to produce smaller molecules or bonds between the substrate molecules are broken to produce smaller molecules

2021 (1)

How can too low and too high temp affect enzyme activity?

Too low:

• enzyme has low kinetic energy

• so fewer (enzyme-substrate) collisions

Too high:

• enzyme denatures

• so substrate can no longer fit

2021: A student investigated the effect of temperature on the activity of amylase.

Table 3 shows the results of the investigation

Explain the results at 5^oC and 80^oC

2021: Which cell is most transparent?

A

2021: Water is taken in by the roots, transported up the plant and lost from the leaves.

Which scientific term describes this movement of water? (1)

Transpiration STREAM

2021: Compare the structure and function of xylem tissue and phloem tissue (6)

Guard cells go _______ to close the stomata

flaccid

Guard cells go ______ to open the stomata

turgid

2021: Describe what happens to cells when a tumour form

cells grow/ divide abnormally/ uncontrollably

2021: In one type of blood transfusion, only red blood cells from a donor are transferred to the patient.

It is dangerous for a patient with blood group A to receive red blood cells from a donor with blood group B.

Explain why (3)

How to prepare a food sample ready for testing (3)

• crush food sample in pestle and mortar

• add distilled water

• stir to dissolve food

• filter solution to remove solid pieces of food

2020: Describe how energy for the photosynthetic reaction is gained by plants (2)

• light

• captured/absorbed by chlorophyll/chloroplasts

2020: (3)

2020: Describe the test for glucose (3)

• add benedicts reagent/solution

• boil/heat

• colour change to brick red

2020: Describe a test for starch (2)

• add iodine SOLUTION (or reagent)

• turns blue-black

2020: Explain why a leaf kept in the light for four days contained both glucose and starch (2)

• glucose from photosynthesis

• excess glucose converted to/ stored as starch

2020: Explain why a leaf left in a cupboard with no light for two days contains glucose but no starch (3)

• starch (stores) have been converted to glucose

• so the glucose can be used for respiration/ metabolic reactions or can be used to release energy

• because there is no light to make new glucose by photosynthesis

2020: How do thorns defend a plant (1)

any one from:

• deter herbivores/ animals eating it

• prevent animals damaging it

2020: (5)

2020: Suggest how the nodules benefit the bacteria (2)

2020: Explain how the nodules benefit the gorse plant (2)

2020: Describe the effects of liver failure on the human body (4)

2020: Describe how clinical trials should be carried out (6)

Specimen:

2020: Describe the transport of water through a plant from the roots to the atmosphere (3)

• water transported in xylem

• water evaporates (from leaves)

• through the stomata

2020: Glucose is absorbed into the blood in the small intestine by both diffusion and active transport.
Describe how the small intestine is adapted for efficient absorption. (5)

2020: Define double circulatory system (1)

blood is pumped to the lungs by one/right side of the heart and blood is pumped to the body by the other/left side of the heart

2020: Explain why having only one ventricle makes the circulatory system less efficient than having two ventricles (2)

oxygenated and deoxygenated blood mixes
so less oxygen reaches body/tissue/cells

2020: Explain why an axolotl may die in water with a low concentration of oxygen (4)

2020: Suggest one reason why an axolotl is a suitable animal for research in the laboratory. (1)

2020: What is an enzyme (2)

• protein

• biological catalyst

2020 (4)

2020: A drug was trialled before it was licensed for use

Why was a placebo and double-blind trial used? (2)

Placebo: (Any one from)

• to avoid patients thinking they feel better with the drug or to take into account a psychological effect

• as a control/comparison

Double Blind trial:

• to avoid bias(ed results)