During ammonium assimilation, requires two enzymes converting ammonium to amino acids. Each of which is Glutamine synthetase (GS), given below some statements about GS ;

a) GS transfers the amide group of glutamine to 2-oxoglutarate, yielding two molecules of glutamate

b) it requires a divalent cation such as Mg2+, Mn2+, or Co2+ as a cofactor

c) Plants contain two classes of GS, one in the cytosol and the other in root plastids or shoot chloroplasts

d) The cytosolic forms are expressed in germinating seeds or in the vascular bundles of roots and shoots and produce glutamate for intercellular nitrogen transport

e) The GS in root plastids generates amide nitrogen for local consumption; the GS in shoot chloroplasts reassimilates photorespiratory NH4+

f) Light and carbohydrate levels alter the expression of the cytosolic forms of the enzyme, but they have little effect on the plastid forms.

Which of the following statements is correct?

#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?

#Question id: 3833

#Unit 3. Fundamental Processes

Regarding DNA replication, which, if any, of the following statements is incorrect?

#Question id: 3834

#Unit 3. Fundamental Processes

In his transformation experiments, what phenomenon did Griffith observe?

#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?