A-Level Biology

Question 1

What is the role of ATP in cellular processes as studied in Singapore A-Level Biology?

Accepted Answer

It is the universal energy currency of cells, providing immediate energy for cellular activities

Answer

It stores genetic information

Answer

It transports oxygen in the blood

Answer

It forms the cell membrane

Question 2

What is the structure of DNA according to the Watson-Crick model?

Accepted Answer

A double helix with antiparallel strands connected by complementary base pairing (A-T, G-C) through hydrogen bonds

Answer

A single-stranded helix

Answer

A triple-stranded structure

Answer

A circular ring structure

Question 3

What is the difference between mitosis and meiosis?

Accepted Answer

Mitosis produces 2 identical diploid cells; meiosis produces 4 genetically different haploid cells

Answer

Mitosis produces 4 cells; meiosis produces 2 cells

Answer

They are the same process

Answer

Mitosis only occurs in plants

Question 4

What is the lock-and-key model of enzyme action?

Accepted Answer

The substrate fits precisely into the enzyme's active site, like a key fitting a lock, forming an enzyme-substrate complex

Answer

Enzymes break apart like keys

Answer

Enzymes are made of metal like locks

Answer

The enzyme changes shape to fit the substrate

Question 5

What is natural selection as described in the Singapore A-Level Biology syllabus?

Accepted Answer

The process by which organisms with favourable inherited traits are more likely to survive and reproduce, passing those traits to offspring

Answer

Organisms choosing their mates

Answer

Farmers selecting the best crops

Answer

A random process with no direction

Question 6

What is the Calvin cycle in photosynthesis?

Accepted Answer

The light-independent reaction where CO₂ is fixed and reduced to form glucose using ATP and NADPH from the light reactions

Answer

The light-dependent reaction

Answer

The process of water splitting

Answer

The electron transport chain in chloroplasts