Biology practice questions

Biology practice questions Set 1: Q1 (Cell Biology) — Fig 1 shows a plant cell and an animal cell. State two structural differences between a plant cell and an animal cell, other than the presence of chloroplasts. [2] Q2 (Movement of Substances) A student places a potato strip into a concentrated salt solution. (a) Name the process by which water moves out of the potato cells. [1] (b) Explain, in terms of water potential, why water moves out of the cells. [3] Q3 (Nutrition — Enzymes) An experiment tested the effect of pH on the activity of amylase, using the iodine test to monitor starch breakdown at 2-minute intervals. (a) Describe how the iodine test is used to show that starch has been broken down. [2] (b) Sketch and describe the shape of a graph of enzyme activity against pH for a typical human enzyme. [3] Q4 (Transport in Humans) (a) State two differences between arteries and veins. [2] (b) Explain why the left ventricle has a thicker muscular wall than the right ventricle. [2] Q5 (Respiration) (a) Write the word equation for anaerobic respiration in muscle cells. [1] (b) Explain why muscle cells respire anaerobically during vigorous exercise. [2] Q6 (Molecular Genetics) (a) Describe the process of transcription. [3] (b) Explain how a mutation in the base sequence of DNA could result in a non-functional protein. [3] Q7 (Homeostasis) Explain how the body responds to a rise in blood glucose concentration after a meal, including the role of insulin. [4]

Q8 (Reproduction) State two functions of amniotic fluid during pregnancy. [2] Set 2: Q1 (Molecular Genetics) (a) State the base pairing rule in DNA. [1] (b) A gene has the DNA template strand base sequence: TAC GGA CTT. State the mRNA sequence produced from this template. [2] Q2 (Genetic Engineering) Describe how a human gene (e.g. the insulin gene) can be inserted into a bacterium to produce a genetically modified organism. [4] Q3 (Enzymes) A student investigated the effect of temperature on the rate of an enzyme-catalysed reaction. (a) Describe how the rate of reaction changes as temperature increases from 10°C to 80°C. [3] (b) Explain, in terms of enzyme structure, why the rate of reaction decreases sharply above the optimum temperature. [3] Q4 (Phot