phloem transport indicating the importance of long distance transport in plants, the experiments demonstrated that removal of a ring of bark around the trunk of a tree, which removes the phloem. What will be its effect?

#Question id: 10372

#Unit 6. System Physiology – Plant

Nod genes, which NodD activates, code for nodulation proteins, most of which are involved in the biosynthesis of Nod factors such as;

 a) Nod factors are lipochitin oligosaccharide signal molecules

 b) Nod factor shave a chitin β-1→ 4-linked N-acetyl-D-glucosamine backbone

 c) These N-acetyl-D-glucosamine backbone varying in length from three to six sugar units

 d) A fatty acid chain on the C-2 position of the nonreducing sugar determine the length and degree of saturation of the fatty acyl chain by NodL

 Which of the following is incorrect?

#Question id: 10371

#Unit 6. System Physiology – Plant

There are three essential nod gene for every bacterial species that is−NodA, NodB and NodC, that are required for synthesizing this basic structure such as;

a) NodA is an N-acyltransferase that catalyzes the addition of a fatty acyl chain

b) NodB is a chitin-oligosaccharide synthase that links the acetyl group of the terminal nonreducing sugar

c) NodC is a chitin-oligosaccharide synthase that links N-acetyl-D-glucosamine monomers

d) NodB is a chitin-oligosaccharide deacetylase that removes the acetyl group from the terminal nonreducing sugar

e) NodC is a chitin-oligosaccharide deacetylase that removes links N-acetyl-D-glucosamine monomers

Which of the following statements about NOD Factor is incorrect?

#Question id: 10367

#Unit 6. System Physiology – Plant

Cyanobcteria also fixes nitrogen under anaerobic conditions without  heterocyst where?

#Question id: 10366

#Unit 6. System Physiology – Plant

Cyanobacteria can fixes nitrogen in an anaerobic conditions. Which of the following statements about heterocyst which is specialized cell of blue-green algae is incorrect?

#Question id: 10365

#Unit 6. System Physiology – Plant

Why the nitrogenase enzymes catalyzes the nitrogen fixation reaction only in microanaerobic or anaerobic conditions?

#Question id: 10364

#Unit 6. System Physiology – Plant

Which of the following is the most common type of symbiosis occurs between members of the plant family and soil bacteria?