Cell biology worksheet with answers

What is phagocytosis?

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

What is diffusion?

1. ANet movement of particles from high to low concentration
2. BMovement of particles against their concentration gradient using ATP
3. CEngulfing of particles by the cell membrane
4. DMovement of water only across a membrane

What is a gene?

1. AA single nucleotide
2. BA DNA sequence that codes for a protein or functional RNA
3. CA whole chromosome
4. DA protein that copies DNA

What directly drives ATP synthase to make ATP in mitochondria?

1. AOxygen diffusing into the matrix
2. BGlucose binding to ATP synthase
3. CProtons flowing back into the matrix down their gradient
4. DElectrons from NADH flowing directly through ATP synthase

How do steroid hormones such as cortisol mainly act on their target cells?

1. AThey cross the membrane and bind intracellular receptors that change gene transcription
2. BThey bind a membrane receptor and open ion channels, changing the cell's membrane potential
3. CThey activate adenylyl cyclase from outside the cell
4. DThey are taken up by phagocytosis and digested

Which motor protein generally carries cargo along microtubules towards the minus end, near the cell centre?

1. AKinesin
2. BActin
3. CMyosin
4. DDynein

A mutation in the lac repressor stops it binding to the operator. What is the result?

1. AThe lac genes are expressed all the time, even without lactose
2. BThe lac genes are expressed only when glucose is present in the medium
3. CThe lac genes can never be expressed
4. DThe bacteria can no longer take up glucose

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. AFrameshift mutation
2. BSilent mutation
3. CNonsense mutation
4. DMissense mutation