Question

1) The universal genetic code is used to translate aminoacids from

a. codons in the DNA

b. codons in the mRNA

c. codons in tRNA

d. codons in rRNA

2) In RNA, introns are:

a. nucleotide sections that do not code for proteins and are not removed before translation

b. nucleotide sections that code for proteins and must be removed before transcription

c. nucleotide sections that do not code for proteins and must be removed before translation

d. nucleotide sections that code for proteins and are removed before translation

3) A Point Mutation or Base-Pair Mutation which results in a premature termination of the polypeptide is called:

a. nonsense mutation

b. missense mutation

c. frameshift mutation

d. silent mutation

4) A promoter is

a. a section of tRNA nucleotides that signals the beginning of translation

b. a section of mRNA nucleotides that signals the beginning of a gene to be transcribed

c. a section of DNA nucleotides that signals the beginning of a gene to be transcribed

d. a section of DNA nucleotides that will promote cellular growth

5) In RNA, Exons are

a. nucleotide sections that do not code for aminoacids and are spliced out

b. nucleotide sections that code for aminoacids and are transcribed from tRNA

c. nucleotide sections that do not code for aminoacids and are not translated

d. nucleotide sections that code for aminoacids and are translated after introns being spliced

Answer 1

The answer to first question is-

b. codons in the mRNA

Explanation- DNA is first transcribed into mRNA. This mRNA has triplets of nucleotides that form codons.Each genetic codon codes for specific aminoacid. This helps in process called translation. Here, mRNA sequences is decoded in order form polypeptides with help of amino acids.

The answer to second question is

c.nucleotide sections that do not code for proteins and must be removed before translation

Explanation- Introns are sections of Nucleotides that do not code for any amino acids. Thus they are useless during translation. It will be simply useless to allow these introns to participate in translation. As in translation we only need codons that code for aminoacids to form chain of polypeptides.Thus introns must be removed out before translation.

The answer to third question is-

a. nonsense mutation.

Explanation-

Nonsense mutation is a mutation in which a codon that codes for aminoacid is changed to codon that codes for terminating the formation of polypeptide chain in translation. This change may occur due to point mutation in that sense codon.

The answer to he fourth question is

c. a section of DNA nucleotides that signals the beginning of a gene to be transcribed .

Explanation- Promoters are the regions in DNA that are located upstream on the DNA near the start site,in case of transcription.