Photorespiration and the quantum yield differ between C3 and C4 photosynthesis, with changes particularly noticeable as temperatures vary quantum yield for photosynthesis as a function of leaf temperature in C3 plants and C4 plants. Following are some statements  based on this study.

 a.) In the C4 plants the quantum yield remains constant with temperature, reflecting low rates of photorespiration

 b.) At lower temperatures the quantum yield of C3 plants is higher than that of C4 plants

c.) C3 photosynthesis is more efficient at lower temperatures

 d.) At higher temperatures the quantum yield of C3 plants is higher  than that of C4 plants

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

#Question id: 4452

#Unit 3. Fundamental Processes

A final DNA element that binds RNA polymerase is sometimes found just downstream from the –10 element. This element is called the

#Question id: 4453

#Unit 3. Fundamental Processes

Correct statements about regions of the s70 factor which can be divided into four regions called s region 1 through s region 4;

#Question id: 4454

#Unit 3. Fundamental Processes

Correct series of sigma regions,

#Question id: 4455

#Unit 3. Fundamental Processes

The __I is connected to the II by a flexible linker, although the II is embedded in the body of the enzyme, the I can reach the upstream element and can do so even when that element is not located immediately adjacent to the –35 region, but further upstream.

#Question id: 4456

#Unit 3. Fundamental Processes

Correct statement about two striking structural changes are seen in the enzyme upon isomerization from the closed to the open complex;

A. First, the pincers at the front of the enzyme clamp down tightly on the downstream DNA.

B. Second, there is a major shift in the position of the amino-terminal region of s. When not bound to DNA, s region 3.2 lies within the active center cleft of the holoenzyme, blocking the path that, in the open complex, is followed by the template DNA strand.

C. In the open complex, region 1.1 shifts some 50 A˚ and is now found on the outside of the enzyme, allowing the DNA access to the cleft.

D. Region 1.1 of s is highly negatively charged ( just like DNA).

#Question id: 4457

#Unit 3. Fundamental Processes

In the holoenzyme, which sigma region acts as a molecular mimic of DNA?