Cell biology worksheet with answers

How do enzymes speed up chemical reactions?

1. AThey lower the activation energy
2. BThey change the reaction's final equilibrium
3. CThey are used up in the reaction
4. DThey raise the temperature of the cell

Which structure allows a sperm cell to swim?

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

Which type of microscope can resolve the smallest structures, such as ribosomes?

1. ADissecting microscope
2. BMagnifying glass
3. CLight microscope
4. DElectron microscope

A competitive inhibitor binds the active site of an enzyme. What can overcome its effect?

1. ARaising the substrate concentration
2. BRemoving the enzyme's cofactor
3. CLowering the temperature to 0 °C
4. DRaising the inhibitor concentration

Which enzyme unwinds the DNA double helix during replication?

1. ADNA polymerase
2. BPrimase
3. CHelicase
4. DDNA ligase

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

1. AAdenylyl cyclase
2. BProtein kinase A
3. CPhosphodiesterase
4. DPhospholipase C

Why does colchicine arrest dividing cells in mitosis?

1. AIt stops tubulin polymerising, so the spindle cannot form
2. BIt breaks down actin filaments, so cytokinesis cannot happen
3. CIt stops DNA replication in S phase
4. DIt destroys the nuclear envelope permanently

A disease is passed from an affected mother to all her children but never from an affected father. Where is the mutation most likely located?

1. AIn mitochondrial DNA
2. BOn an autosome, as a recessive trait
3. COn the Y chromosome
4. DOn the X chromosome, as a dominant trait