Question

Multiple Choice

Cellular respiration and photosynthesis each employ an electron transport chain. Which statement below do the two electron transport gains not have in common?

a.They both generate a proton (H+) gradient across a membrane

b.They both involve redox reaction s

c.They both occur in plant cells

d.They both are embedded within a membrane

e.Each of the above is shared by each electron transport chain

Why do linear chromosomes become shorter each time DNA replication occurs?

a.The leading strand cannot be completely synthesized,since DNA polymerase cannot add the last few bases once it reaches the end of a chromosome

b.Once the RNA primer is removed from the end of the lagging strand, DNA polymerase has nothing to which it can add new nucleotides

c.Telomerase always removes the last several bases on a lagging strand

d.Primase cannot add an RNA primer without a DNA primer

e.None of the above

Why is the rate of misincorporated bases during DNA synthesis so low?

a.Only A-T and G-C base pairs can fit into DNA polymerase’s active site

b.After an entire chromosome is synthesized, DNA polymerase goes through and double checks it work.

c.If an incorrect base is added, DNA polymerase immediately removes the base and adds the correct base

d.a&b

e.a&c

Answer 1

1) complexes involved in the cellular respiration are located in the inner mitochondrial membrane and complexes involved in photosynthesis light reactions are found in the thylakoid membrane. in light reactions the electrons from photosystem II is excited and it moves through the electron transport chain, complexes transfers electrons from one component to another, that is it nvolves the oxidation and reduction , similarly in mitochondrial electron transport chain, first the reduced coenzymes ( NADH and FADH2) are oxidises and electrons moves moves through the complexes, complexes transfers electrons from one component to another, that is it nvolves the oxidation and reduction, in both mitochondrial electron transport and light reactions in chloroplast, H+ is pumped across the membrane to generate an H+ gradient. In plants light reactions occurs in the chloroplasts and mitochondrial electron transport occurs during cellular respiraion so the answer is e) each of the above is shared by each electron transport chain