O-Level Combined Science — Biology 4 — Questions and Answers
Question 1: What type of reproduction requires only one parent and produces genetically identical offspring?
- Sexual reproduction
- Cross-pollination
- Asexual reproduction (Correct answer)
- Fertilisation
Correct answer: Asexual reproduction
Asexual reproduction involves only one parent and produces offspring that are genetically identical (clones) to the parent.
Question 2: What is the role of the pancreas in digestion?
- Absorbs nutrients
- Stores bile
- Produces digestive enzymes (Correct answer)
- Filters blood
Correct answer: Produces digestive enzymes
The pancreas produces digestive enzymes (amylase, lipase, protease) that are released into the small intestine to break down food.
Question 3: Which gas do plants absorb from the air for photosynthesis?
- Oxygen
- Nitrogen
- Carbon dioxide (Correct answer)
- Hydrogen
Correct answer: Carbon dioxide
Plants absorb carbon dioxide (COâ‚‚) from the air through their stomata and use it as a raw material for photosynthesis.
Question 4: What is natural selection?
- Humans choosing which animals to breed
- Organisms with favourable traits surviving and reproducing more successfully (Correct answer)
- The extinction of all organisms
- The process of mutation only
Correct answer: Organisms with favourable traits surviving and reproducing more successfully
Natural selection is the process by which organisms with advantageous traits are more likely to survive, reproduce, and pass on those traits to offspring.
Question 5: Which structure controls what enters and leaves the cell?
- Cell wall
- Nucleus
- Cytoplasm
- Cell membrane (Correct answer)
Correct answer: Cell membrane
The cell membrane (plasma membrane) is selectively permeable, controlling the movement of substances into and out of the cell.
Question 6: What is the medical term for a condition where arteries are blocked by fatty deposits?
- Diabetes
- Atherosclerosis (Correct answer)
- Hypertension
- Anaemia
Correct answer: Atherosclerosis
Atherosclerosis is the build-up of fatty plaques (atheroma) inside artery walls, narrowing them and restricting blood flow, increasing heart disease risk.
O-Level Combined Science — Biology 4
What type of reproduction requires only one parent and produces genetically identical offspring?