Cell biology worksheet with answers

Which structure allows a sperm cell to swim?

1. ACilium
2. BCell wall
3. CFlagellum
4. DMicrovillus

What is phagocytosis?

1. AThe movement of water across a membrane
2. BThe uptake of small ions through channels
3. CThe uptake of large particles by engulfing them in membrane
4. DThe release of proteins from the cell in membrane-bound vesicles

What is the main role of the nucleolus?

1. ABreaking down damaged proteins that are tagged with ubiquitin
2. BMaking ribosomal RNA and assembling ribosome subunits
3. CCopying the whole genome
4. DStoring ATP for the nucleus

Where in the cell does the citric acid (Krebs) cycle take place?

1. ACytoplasm
2. BIntermembrane space
3. CMitochondrial matrix
4. DInner mitochondrial membrane

What role does cholesterol play in animal cell membranes?

1. AIt forms channels for ions
2. BIt makes the membrane completely rigid at every temperature
3. CIt is the main carrier of glucose
4. DIt helps keep membrane fluidity stable across temperatures

How do large proteins such as transcription factors enter the nucleus?

1. ABy diffusing freely through the nuclear membrane lipids
2. BThrough nuclear pore complexes, guided by a nuclear localisation signal
3. CThey are made inside the nucleus by nuclear ribosomes, so they never enter
4. DBy exocytosis from the endoplasmic reticulum

Sickle cell disease is caused by a single base substitution that changes glutamate to valine in beta-globin. What type of mutation is this?

1. ANonsense mutation
2. BFrameshift mutation
3. CSilent mutation
4. DMissense mutation

Which statement about the sodium–potassium pump is correct?

1. AIt moves 2 Na⁺ out and 3 K⁺ in
2. BIt moves Na⁺ and K⁺ in the same direction across the membrane
3. CIt moves 3 Na⁺ out and 2 K⁺ in for each ATP used
4. DIt needs no energy