Question

1. A loss of 3′ polyadenylation will lead to:

a. intensified splicing of mRNA.

b. intensified capping.

c. decreased stability of the mRNA.

d. intensified splicing of tRNA.

e. alternative splicing.

2. What is the function of helicase?

a. It eliminates supercoils by cleaving DNA.

b. It utilizes the energy of ATP to add negative supercoils to DNA.

c. It removes mismatched nucleotides from the 3′ end of DNA.

d. It utilizes the energy of ATP for separation of strands.

e. It primes synthesis of DNA.

3. Choose the CORRECT fact about RNA.

a. unbranched polymer consisting of nucleotides A, G, C, T; the sugar is deoxyribose

b. unbranched polymer consisting of nucleotides A, G, C, U; the sugar is deoxyribose

c. unbranched polymer consisting of nucleotides A, G, C, T; the sugar is glucose

d. unbranched polymer consisting of nucleotides A, G, C, U; the sugar is ribose

e. branched polymer consisting of nucleotides A, G, U, C; the sugar is fructose

Answer 1

Answer:

1). c. decreased stability of the mRNA.

Explanation:

In nuclear polyadenylation, a poly(A) tail is added to an RNA at the end of transcription. On mRNAs, the poly(A) tail protects the mRNA molecule from enzymatic degradation in the cytoplasm and aids in transcription termination, export of the mRNA from the nucleus, and translation.

2). d. It utilizes the energy of ATP for separation of strands.

Explanation:

An enzyme called helicases utilizes the energy in the form of ATP hydrolysis to power strand separation.

3). d. unbranched polymer consisting of nucleotides A, G, C, U; the sugar is ribose

Explanation:

DNA consists of A, G, T & C nucleotides and deoxyribose sugar.

RNA consists of A, G, U & C nucleotides and ribose sugar.