Cell biology worksheet with answers

What is phagocytosis?

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

What is exocytosis?

1. AMovement of ions through protein pumps
2. BUptake of fluid and dissolved solutes into small vesicles formed by the membrane
3. CBreakdown of the cell membrane
4. DRelease of substances from the cell by vesicles fusing with the membrane

Which statement is part of the cell theory?

1. AAll cells come from pre-existing cells
2. BAll cells are the same size
3. CAll cells contain a nucleus
4. DAll cells can perform photosynthesis

Which cytoskeletal filaments mainly give cells resistance to mechanical stress, such as keratin in skin?

1. ASpindle fibres
2. BMicrotubules
3. CActin microfilaments
4. DIntermediate filaments

Which cell junction lets ions and small molecules pass directly between neighbouring cells?

1. ADesmosome
2. BAdherens junction
3. CTight junction
4. DGap junction

During which phase of mitosis do sister chromatids separate?

1. AAnaphase
2. BMetaphase
3. CProphase
4. DTelophase

In the Hershey–Chase experiment, phages labelled with ³²P and ³⁵S infected bacteria. What was found inside the bacteria?

1. AMostly ³²P, showing DNA enters the cell
2. BEqual amounts of both labels
3. CMostly ³⁵S, showing protein enters the cell
4. DNeither label, because phages stay outside

Cholera toxin modifies the alpha subunit of Gs so it cannot hydrolyse GTP. Why does this cause severe watery diarrhoea?

1. AcAMP falls, so gut cells stop absorbing water and sodium from the lumen
2. BcAMP stays high in gut cells, driving chloride and water secretion
3. CThe toxin destroys the villi
4. DThe toxin blocks aquaporins in the colon