GCSE Biology 2 — Questions and Answers
Question 1: Which organelle is responsible for producing ATP through aerobic respiration in eukaryotic cells?
- Ribosome
- Mitochondria (Correct answer)
- Chloroplast
- Golgi apparatus
Correct answer: Mitochondria
Mitochondria carry out aerobic respiration, producing ATP via the Krebs cycle and oxidative phosphorylation.
Question 2: What is the role of guard cells in a plant leaf?
- Absorb sunlight for photosynthesis
- Regulate the opening and closing of stomata (Correct answer)
- Transport water from roots to leaves
- Produce glucose during respiration
Correct answer: Regulate the opening and closing of stomata
Guard cells control stomatal aperture, regulating gas exchange and water loss through transpiration.
Question 3: During which phase of meiosis do homologous chromosomes separate?
- Meiosis I (Correct answer)
- Meiosis II
- Prophase II
- Anaphase II
Correct answer: Meiosis I
Homologous chromosome pairs separate during Meiosis I, reducing the chromosome number from diploid to haploid.
Question 4: Which blood vessel carries oxygenated blood from the lungs back to the heart?
- Pulmonary artery
- Aorta
- Pulmonary vein (Correct answer)
- Vena cava
Correct answer: Pulmonary vein
The pulmonary vein is unique among veins in carrying oxygenated blood, returning it from the lungs to the left atrium.
Question 5: What term describes an organism that obtains energy by breaking down dead organic matter?
- Producer
- Predator
- Decomposer (Correct answer)
- Parasite
Correct answer: Decomposer
Decomposers such as bacteria and fungi break down dead organic matter, recycling nutrients back into the ecosystem.
Question 6: Which molecule acts as the universal energy currency in living cells?
- ADP
- DNA
- ATP (Correct answer)
- RNA
Correct answer: ATP
ATP (adenosine triphosphate) stores and releases energy for cellular processes via its high-energy phosphate bonds.
Question 7: What is the function of the corpus luteum after ovulation?
- It releases FSH to trigger ovulation
- It secretes progesterone to maintain the uterine lining (Correct answer)
- It stores unfertilised eggs
- It produces oestrogen to trigger menstruation
Correct answer: It secretes progesterone to maintain the uterine lining
The corpus luteum forms from the follicle after ovulation and secretes progesterone to maintain the endometrium for potential implantation.
GCSE Biology 2
Which organelle is responsible for producing ATP through aerobic respiration in eukaryotic cells?