Practice 4 MCQ Questions

1. A culture of yeast cells was started in a nutrient medium. Three days later, a culture of the protozoan Paramecium was added. The numbers of yeast cells and Paramecium were recorded and are shown in the graph below. The units of the two vertical scales are different.


Why are the two curves so similar in shape?
A. Paramecium feeds on yeast cells.
B. Yeast feeds on dead Paramecium cells.
C. Paramecium and yeast have the same lifespan.
D. Paramecium and yeast compete for the nutrient medium.

2. The family tree below was assembled by a genetic counsellor for Mr and Mrs X who suffer from heart disease due to hypercholesterolaemia. Children who inherit the dominant mutant allele from both parents rarely survive beyond puberty.


What is the probability that Mr and Mrs X’s third child will be unaffected?
A. 0.25
B. 0.50
C. 0.75
D. 1.00

3. The diagram below shows part of the gut, liver, pancreas and associated blood vessels.


Which of these are least likely to be present in the blood carried by the blood vessel labelled X?
A. Amino Acids
B. Fructose
C. Glucose
D. Glycerol

4. Which of the following cells has the most mitochondria?
A. Sperm
B. Erythrocyte
C. Epithelium
D. Palisade

5. Which of the following are examples of osmosis?
1. The absorption of water by root hairs.
2. The absorption of mineral salts by root hairs.
3. The absorption of water by dry cotton wool.
4. The shrinkage of a piece of fresh meat in salt solution.
5. Plasmolysis of epidermal cells of an onion scale leaf.

A. 1, 4 and 5 only
B. 3, 4 and 5 only
C. 1, 2, 4 and 5 only
D. 1, 3, 4 and 5 only

6. Enzymes are highly specific in the reactions they catalyse. Which of the following statements explains this characteristic of enzymes?
A. Protein molecules consist of many amino acids.
B. Protein molecules consist of helical structures.
C. Each enzyme molecule has a distinctive configuration.
D. Protein molecules are denatured by high temperature.

7. The diagram below shows part of the shoot system of a fruit tree. At the two places marked R, all the tissue external to the xylem was removed at the flowering stage. The diagram suggests that ___________________________________.


A. food is transported downwards in the phloem and water upwards in
xylem vessels.
B. food is transported in phloem tubes regardless of direction.
C. fruit Y is not getting enough water.
D. fruit X and Z received more light than Y.

8. The leaf from a dicotyledonous herb is supplied with radioactive carbon dioxide. Which one of the following transverse sections of the stem shows correctly the stained area that the radioactivity first appears?



Questions 9 and 10 refer to the graph below.


9. Which one of the following is not shown in the graph?
A. Carbon dioxide is important for photosynthesis.
B. Increasing light intensity increases rate of photosynthesis.
C. Rate of photosynthesis depends on the amount of water that is available.
D. Rate of photosynthesis is always higher when there is higher carbon dioxide concentration.

10. What is the limiting factor at X?
A. Carbon dioxide concentration
B. Light intensity
C. Temperature
D. Water