Paper 1-style practice paper: Cell biology · Organisation · Infection and response · Bioenergetics (Higher) — question paper

Section A: Multiple-choice questions[10 marks]

Choose one answer for each question. Each question is worth 1 mark.

1. 1

   Which statement about mitosis is correct?

   1. Athe chromosome number halves
   2. Btwo genetically identical diploid cells form
   3. Cfour genetically different cells form
   4. Dgametes are produced
   ( )
2. 2

   A cell is 0.05 mm wide and its image is 7.5 mm wide. The magnification is

   1. A×15
   2. B×375
   3. C×0.007
   4. D×150
   ( )
3. 3

   In the osmosis practical, percentage change in mass is calculated rather than change in grams because

   1. Athe cylinders start at different masses
   2. Bwater has no mass
   3. Cgrams are not SI units
   4. Dbalances measure in milligrams
   ( )
4. 4

   Which organ makes all three types of digestive enzyme?

   1. Athe liver
   2. Bthe gall bladder
   3. Cthe pancreas
   4. Dthe large intestine
   ( )
5. 5

   Cultures of microorganisms in school laboratories are incubated at a maximum of 25 °C to

   1. Aslow the growth of harmful pathogens
   2. Bsterilise the agar
   3. Cmelt the agar
   4. Dadd nutrients
   ( )
6. 6

   Monoclonal antibodies are produced by

   1. Awhite blood cells alone
   2. Blymphocytes fused with tumour cells
   3. Cbacteria in a fermenter
   4. Dplant cells in tissue culture
   ( )
7. 7

   By the inverse square law, doubling the distance from a lamp makes the light intensity

   1. Adouble
   2. Bstay the same
   3. Cfour times bigger
   4. Da quarter as big
   ( )
8. 8

   During protein synthesis, transcription happens in the

   1. Anucleolus
   2. Bmitochondrion
   3. Cnucleus
   4. Dribosome
   ( )
9. 9

   Anaerobic respiration in yeast cells produces

   1. Aethanol and carbon dioxide
   2. Blactic acid only
   3. Coxygen and glucose
   4. Dprotein and water
   ( )
10. 10

    A plant is deficient in magnesium, so which process falls first?

    1. Arespiration
    2. Bphotosynthesis
    3. Cdigestion
    4. Devaporation
    ( )

Section B: Structured questions[90 marks]

Answer all questions in the spaces provided.

1. 11

   This question is about cell division, stem cells and exchange.

   1. (a)

      Describe what happens to the chromosomes during mitosis.

      [3]
   2. (b)

      Compare embryonic stem cells with adult stem cells in medicine, and give one reason some people object to using embryonic stem cells.

      [3]
   3. (c)

      A plant cell measures 12 mm across in a micrograph. Its real width is 0.003 mm. Calculate the magnification, and give the real width in micrometres (µm).

      [4]
   4. (d)

      Explain how the alveoli are adapted for fast gas exchange, referring to diffusion distance, surface area and concentration gradient.

      [4]
2. 12

   This question is about transport in cells.

   1. (a)

      A potato chip has a mass of 3.2 g before and 2.6 g after 30 minutes in a strong sucrose solution. Calculate the percentage change in mass, to 1 decimal place.

      [4]
   2. (b)

      Explain why an animal cell placed in pure water bursts, but a plant cell in the same conditions only becomes firm.

      [3]
   3. (c)

      Explain how active transport differs from diffusion, and give one example of active transport in plants.

      [4]
   4. (d)

      A plant is left in a concentrated salt solution. Explain what happens to its cells.

      [3]
3. 13

   This question is about enzymes.

   1. (a)

      In an amylase experiment, starch digestion takes 40 s at pH 6 and 20 s at pH 7. Calculate the rate of digestion at each pH, in reactions per minute, and describe the pattern.

      [4]
   2. (b)

      Explain how a temperature above the optimum denatures an enzyme.

      [3]
   3. (c)

      Describe how starch is digested to glucose in the human gut, naming the enzymes and the intermediate product.

      [4]
   4. (d)

      Explain how the villi of the small intestine speed up absorption.

      [3]
4. 14

   This question is about the heart, circulation and disease.

   1. (a)

      Explain one advantage of the double circulatory system in mammals.

      [3]
   2. (b)

      Describe the natural pacemaker of the heart: where it is and what it does.

      [3]
   3. (c)

      A patient with narrowed coronary arteries is offered either statins or a stent. Evaluate the two treatments.

      [5]
   4. (d)

      Compare benign and malignant tumours, explain how malignant tumours spread, and give two risk factors for cancer.

      [5]
5. 15

   This question is about infection, immunity and drug development.

   1. (a)

      Explain how white blood cells give immunity against a specific pathogen.

      [3]
   2. (b)

      Explain how vaccinating most of a population protects people who have not been vaccinated.

      [3]
   3. (c)

      Describe three uses of monoclonal antibodies and give one limitation of their use in medicine.

      [5]
   4. (d)

      Describe the stages of testing a new drug, and explain why double-blind trials with placebos are used.

      [5]
6. 16

   This question is about photosynthesis and respiration.

   1. (a)

      A lamp is moved from 10 cm to 20 cm from pondweed. Using the inverse square law, state how the light intensity changes, and show your reasoning with units of relative intensity.

      [4]
   2. (b)

      A graph of photosynthesis rate against light intensity rises steeply at first and then flattens out. Explain what limits the rate in each region.

      [4]
   3. (c)

      Compare what happens in muscle cells during vigorous exercise when oxygen runs short with what happens when oxygen is plentiful.

      [4]
   4. (d)

      Define metabolism, give two examples of metabolic reactions, and explain why muscle cells contain many mitochondria.

      [4]