Question

4. Termination of replication in prokaryotes

5. Which of the following statements regarding r RNA is correct:

a) The most common of all RNA structures

b) It comes in the form of a single-chain molecule

c) It comes in the form of a double-stranded molecule

d) The structure contains a large number of loops, loops and bubbles

e) It comes in the nucleus of the cell

6. The characteristics of m RNA synthesis are:

a) takes place in the nucleus of the cell

b) takes place in the cytoplasm of the cell

c) nucleotides are linked by phosphodiester bonds

d) takes place on the DNA coding strand

e) energy from the hydrolysis of pyrophosphate is required for the process of m RNA biosynthesis

7. Leucine - zipper proteins

8. Lac operon

9. The significant difference between prokaryotes and eukaryotes is as follows:

a. Prokaryotes do not have DNA, as genetic material, while eukaryotes have

b. Prokaryotes do not have ribosomes, while eukaryotes have

c. Prokaryotic cells are not membrane-bound, whereas eukaryotic ones are

d. Eukaryotic DNA floats freely in the cell, while prokaryotic DNA is located in the cell nucleus

e. Nothing is true

Answer 1

4. DNA replication is process of duplication of DNA. Termination of replication in prokaryotes occur when two oppositely oriented replication fork meet and fuse and hence creates two seperate and double stranded DNA molecules.

5. rRNA is most abundant RNA so first option is correct.

As every RNA is single stranded , rRNA is also single stranded so option b is correct and option C is incorrect.

rRNA is found in cytoplasm where ribosome are found.so option E is also incorrect.

rRNA also contains loops and bubble so option D is correct.

6. Process of synthesis of mRNA is called transcription and synthesis occurs in nucleus.so option A is correct and option B is incorrect.

Nucleotide is linked by phosphodiester bond so option C is correct.

mRNA synthesis is from DNA no coding strand.so option D is incorrect.

On hydrolyzing pyrophosphate ,a lot of energy released which is used in mRNA synthesis.so option E is correct.

7. Leucine zipper is three dimensional structure motif in protein. Leucine zipper motif consists of periodic repetation of leucine residue at every seventh position which forms helical confirmation which facilitates dimerization of protein.