RNA synthesis differs from DNA synthesis in the followings w

RNA synthesis differs from DNA synthesis in the followings ways:
1 - RNA synthesis does not require a primer but DNA synthesis does.
2 - RNA polymerase does not have proofreading ability, but DNA polymerase does.
3 - The error rate of RNA synthesis is 100 to 1000 times greater than that in DNA synthesis.
4 - RNA synthesis occurs in the 3\' to 5\' direction whereas DNA synthesis occurs in the 5\' to 3\' direction.

1, 2, 3, and 4

1, 3, and 4

2, 3, and 4

1, 2, and 3

1 and 2   

On Mars, it seems, the genetic material is double-stranded RNA rather than DNA. Martian RNA polymerase uses double-stranded RNA as a template to make mRNA; it is a RNA-directed RNA polymerase. Assume all other aspects of transcription and translation and the functions and integrity of the enzymes involved are the same on Mars as on Earth (i.e., RNA has the same function, the same base pairs are complementary to each other, and chemistry in general is the same). Over time, the integrity of the genetic message in Martian RNA would:

Decline more rapidly than that of DNA because of the lack of an editing function of RNA polymerase.

Be comparable with that of DNA.

Decline more rapidly than that of DNA because of the deamination of cytosine to uracil in RNA would lead to mutations.

Be greater than that of DNA because the message would be more direct: RNA to protein, with one less step in which mistakes could happen.

a and c are true.   

In ?-independent termination, the termination sequence is on the _______ and the hairpin structure is formed by the _____.

DNA; RNA

RNA; DNA

DNA; ? protein

RNA; RNA

DNA; DNA-RNA hybrid

________ is found within the transcription bubble.

Positive supercoils in the DNA

Negative supercoils in the DNA

An intact DNA duplex

A short DNA-RNA hybrid

An RNA primer

Solution

1. (d)RNA synthesis occurs in the 3\' to 5\' direction whereas DNA synthesis occurs in the 5\' to 3\' direction.

2. (a) Decline more rapidly than that of DNA because of the lack of an editing function of RNA polymerase.

3 (a) DNA; RNA

4. (a) positive supercoils