You set up an experiment in which you breed two populations of true-breeding pea plants. The first true-breeding population has yellow round seeds and the second has green wrinkled seeds. All of the F1 plants yield yellow round seeds. When you self -fertilize the F1 the F2 generation yields a mixture of yellow round, yellow wrinkled, green round and green wrinkled seeds. What does this tell you about the alleles for seed color and shape?

#Question id: 3827

#Unit 3. Fundamental Processes

It takes about the same amount of time for eukaryotic chromosomes to be replicated in vivo as it does for E. coli. Why is this true?

#Question id: 3828

#Unit 3. Fundamental Processes

Why does E. coli need both DNA polymerase III and DNA polymerase I?

#Question id: 3829

#Unit 3. Fundamental Processes

Why is only one copy of DNA made per cell division cycle in eukaryotes despite the presence of multiple origins of replication?

#Question id: 3830

#Unit 3. Fundamental Processes

Why is DNA damage in skin cells from exposure to excessive UV light not completely reversed by photoreactivation?

#Question id: 3831

#Unit 3. Fundamental Processes

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

1. In E. coli replication begins at the origin of replication and proceeds in one direction until the entire circular DNA molecule has been copied.

2. The chromosome of the fruit fly (D. melanogaster) is about twice as large as the E. coli chromosome.

3. Prokaryotic DNA replication occurs in two steps. First, ATP provides a phosphate to the growing DNA chain. This is followed by addition of a nucleoside.

4. DNA polymerase III is the largest DNA polymerase in E. coli.

5. The β subunits of E. coli DNA polymerase form a sliding clamp that surrounds the DNA strands at the replication fork.

#Question id: 3832

#Unit 3. Fundamental Processes

You briefly expose bacteria undergoing DNA replication to radioactively labeled nucleotides. When you centrifuge the DNA isolated from the bacteria, the DNA separates into two classes. One class of labeled DNA includes very large molecules (thousands or even millions of nucleotides long), and the other includes short stretches of DNA (several hundred to a few thousand nucleotides in length). Which two classes of DNA do these different samples represent?