GCSE Cell Biology 3 — Questions and Answers
Question 1: What is the term for a cell that contains two complete sets of chromosomes?
- Haploid
- Diploid (Correct answer)
- Triploid
- Polyploid
Correct answer: Diploid
Diploid cells (2n) contain two sets of chromosomes, one from each parent.
Question 2: Which molecule carries genetic instructions from the nucleus to the ribosome?
- tRNA
- DNA
- mRNA (Correct answer)
- rRNA
Correct answer: mRNA
Messenger RNA (mRNA) is transcribed from DNA in the nucleus and carries the genetic code to ribosomes for translation.
Question 3: A plant cell placed in a concentrated (hypertonic) solution will most likely undergo which change?
- Turgidity — cell wall expands outward
- Plasmolysis — cell membrane pulls away from the cell wall (Correct answer)
- Lysis — the cell bursts
- Mitosis — the cell divides to dilute the solution
Correct answer: Plasmolysis — cell membrane pulls away from the cell wall
In a hypertonic solution, water leaves the plant cell by osmosis, causing the cell membrane to shrink away from the cell wall — a process called plasmolysis.
Question 4: Which structure controls the movement of substances into and out of the cell?
- Cell wall
- Nucleus
- Cell membrane (Correct answer)
- Cytoplasm
Correct answer: Cell membrane
The partially permeable cell membrane selectively controls which substances enter and leave the cell.
Question 5: What does the term 'differentiation' mean in cell biology?
- A cell dividing into two identical copies
- A cell becoming specialised to perform a specific function (Correct answer)
- A cell undergoing programmed death
- A cell repairing damaged DNA
Correct answer: A cell becoming specialised to perform a specific function
Differentiation is the process by which a cell develops into a specialised type with a specific structure and function.
Question 6: In which organelle does photosynthesis take place?
- Mitochondrion
- Chloroplast (Correct answer)
- Vacuole
- Nucleus
Correct answer: Chloroplast
Chloroplasts contain chlorophyll and are the site of photosynthesis in plant and algal cells.
Question 7: Which of the following is NOT a feature of prokaryotic cells?
- Circular DNA
- Cell membrane
- Membrane-bound nucleus (Correct answer)
- Ribosomes
Correct answer: Membrane-bound nucleus
Prokaryotic cells lack a true nucleus; their DNA floats freely in the cytoplasm, unlike eukaryotic cells.
GCSE Cell Biology 3
What is the term for a cell that contains two complete sets of chromosomes?