Cell biology worksheet with answers

Which structure allows a sperm cell to swim?

1. ACilium
2. BMicrovillus
3. CCell wall
4. DFlagellum

Which organelle breaks down hydrogen peroxide using the enzyme catalase?

1. APeroxisome
2. BGolgi apparatus
3. CLysosome
4. DRibosome

Which organelle carries out photosynthesis?

1. AGolgi apparatus
2. BMitochondrion
3. CChloroplast
4. DNucleus

What role does cholesterol play in animal cell membranes?

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

Which enzyme makes the second messenger cyclic AMP when activated by a Gs protein?

1. APhosphodiesterase
2. BPhospholipase C
3. CAdenylyl cyclase
4. DProtein kinase A

Why does inserting a single nucleotide into a coding sequence usually have a large effect?

1. AIt changes the sugar in the DNA backbone
2. BIt stops the gene from being transcribed into messenger RNA
3. CIt always changes one amino acid only
4. DIt shifts the reading frame of all following codons

In the intrinsic (mitochondrial) pathway of apoptosis, which event leads to caspase activation?

1. ARelease of cytochrome c from mitochondria into the cytosol
2. BEntry of glucose into the mitochondria
3. CFusion of lysosomes with the nucleus
4. DBinding of a death ligand to the Fas receptor on the cell surface

Brown fat contains thermogenin (UCP1), which lets protons leak back across the inner mitochondrial membrane. What is the effect?

1. AThe cell switches to fermentation
2. BEnergy from the proton gradient is released as heat instead of making ATP
3. CThe electron transport chain stops working because protons can no longer be pumped
4. DMore ATP is made per glucose