Two other major groups of flavonoids found in flowers and leaves of all green plants. The function of these two flavonoids in plants are____

a) protect plants against being eaten by herbivores and against being infected by microbial pathogens

b) Protect cells from excessive UV-B radiation (280–320 nm) because they accumulate in the epidermal layers of leaves and stems and absorb light strongly in the UV-B region       

c) flavones and flavonols secreted into the soil by legume roots mediate the interaction of legumes and nitrogen-fixing symbionts

d) They are are coloured terpenoid compounds that also serve as accessory pigments in photosynthesis    

Which of the following combination from the above statements is correct?

#Question id: 3835

#Unit 3. Fundamental Processes

State whether the following statements is true/false regarding DNA replication.

1. A short primer is added to the DNA polymerase reaction mix for Sanger DNA sequencing that has a 5ʹ free hydroxyl to which new nucleotides can be added.

2. In a sequencing gel, all fragment in one of the four lanes terminates in the same type of nucleotide base.

3. Eukaryotic cells contain at least five DNA polymerases all of which are responsible for nuclear DNA replication.

4. Since the rate of form movement in eukaryotes is much slower than that of bacteria, chromosomes require more than an hour to replicate.

5. Although histones and DNA are made in the same parts of the eukaryotic cell, the packaging of them in the nucleosome slows down replication so that it is slower than that of prokaryotes.

#Question id: 3836

#Unit 3. Fundamental Processes

Which of the following statements accurately describes the differences between DNA replication in prokaryotes and DNA replication in eukaryotes?

#Question id: 3837

#Unit 3. Fundamental Processes

How does the enzyme telomerase meet the challenge of replicating the ends of linear chromosomes?

#Question id: 3838

#Unit 3. Fundamental Processes

Which of the following statements correctly describes the difference between the leading and the lagging strands of DNA during DNA replication?

#Question id: 3839

#Unit 3. Fundamental Processes

Use the figure to answer the following question. In the late 1950s, Meselson and Stahl grew bacteria in a medium containing "heavy" (radioactive) nitrogen (15N) and then transferred them to a medium containing 14N (nonradioactive). Which of the results in the figure would be expected after one round of DNA replication in the presence of 14N?

#Question id: 3840

#Unit 3. Fundamental Processes

The mechanism of DNA replication is studied in an E. coli replication fork. When will this fork stop replicating DNA?