Question

Transcription requires _____ to add nucleotides to form an new molecule.

Question 58 options:

	a) DNA polymerase
	b) RNA polymerase
	c) ribosomes
	d) tRNA

Question 59 (2 points)

The large ribosomal subunit

Question 59 options:

	a) is the first to bind mRNA near the start codon
	b) functions as an enzyme to catalyze peptide bonds between amino acids
	c) is stored in the nucleus
	d) removes introns from pre-mRNA

Question 60 (2 points)

Which is the mRNA complement of the DNA sequence 3’ ATTCCGAGCTTA 5’?

Question 60 options:

	a) 5’ UAAGGCUCGAAU 3’
	b) 5’ ATTCCGAGCTTA 3’
	c) 5’ TAAGGCTCGAAT 3’
	d) 5’ AUUCCGAGCUUA 3’

Question 61 (2 points)

Which is the mRNA complement of the DNA sequence 5’ ACGGTCGGAT 3’

Question 61 options:

	a) 5’ AUCCGACCGU 3’
	b) 5’ ACGGTCGGAT 3’
	c) 5’ UGCCAGCCUA 3’
	d) 5’ TGCCAGCCTA 3’

Question 62 (2 points)

During elongation, a new peptide (protein) is produced

Question 62 options:

	a) in sets of three amino acids
	b) one base pair at a time
	c) one amino acid at a time
	d) one ribosome at a time

Question 63 (2 points)

The stop codon causes

Question 63 options:

	a) ribosomal subunits to come together on the mRNA molecule
	b) transcription to end
	c) RNA polymerase to proofread a peptide before the next amino acid is added
	d) ribosomal subunits to dissociate from the mRNA molecule

Question 64 (2 points)

The first stage of translation is known as:

Question 64 options:

	a) elongation
	b) initiation
	c) release
	d) termination

Question 65 (2 points)

Which of the following transfer RNA binding sites are found on the ribosome?

Question 65 options:

	a) depends on the ribosome
	b) A, C, U
	c) A, G, T
	d) A, P, E

Question 66 (2 points)

What type of mutation has occurred in the sample compared to the reference sequence?

Reference sequence: 5’ A T G C C T G A T T G C 3’

Sample sequence: 5’ A T G C C T T A T T G C 3’

Question 66 options:

	a) Deletion
	b) Insertion
	c) Silent
	d) Substitution

Answer 1

Question 58:-

Th right option is option (b) RNA polymerase

Explanation:-

DNA polymerase is the enzyme which is responsible for the synthesis of new DNA molecules using existing DNA molecule as a template. Thus it is used in replication.

Ribsosomes are the oraganelles which are used in the production of protein during the translation process meanwhile tRNA brings amino acids to the ribosomes for elongation.

It is the RNA polymerase enzyme which uses DNA as a template for the production of RNA molecules.

Question 59:-

The right option is option (b) functions as an enzyme to catalyze peptide bonds between amino acids.

Explanation:-

Large ribosomal subunit (50S in prokaryotes) is the subunit of the ribosome which contain the P-site. P site is also known as Peptidyl site and it is the site which transfer the peptide bond between the peptide chain and the incoming site. Thus, large subunit of ribosomes plays the role of catalysing the formation of peptide bonds in between amino acids and thus in elongation.

Question 60:-

The right option is option (a) 5’ UAAGGCUCGAAU 3’

Explanation:-

First of all, RNA do not have thymine in them. Instead they have Uracil, so we can eliminate the options which have T in them as they are DNA molecules, not of RNA.

Now the given molecule have 3'-end on the left meaning complimentary will have 5'-end on the left. Now to determine the complimentary nucleotides, the rule is simple. A with U, U with A, C with G and G with C, that is the rule for mRNA complementary nucleotide determination. The given DNA starts with A, so the RNA molecule start with U and there is only option A with U as the starting molecule. The rest can be checked by the complementary rule.

Question 61:-

The right option is option (A) 5’ AUCCGACCGU 3'

Explanation:-

This also follows the rule like above and again the rule of base pairing and complementary remains the same but in this question, the given nucleotides of DNA are in 5' to 3' (meaning 5' end is on left) and the given RNA molecule are also in 5' to 3' direction. The two strands are always anti-parallel even if the duplex of this is DNA-RNA hybrid.

So, to decide this question's answer we will have to read the mRNA in reverse direction.

This means that in DNA molecule the nucleotide at 5' end is A, so the nucleotide at the 3' end of the mRNA molecule should be U (which in this case the 3' end is at the very end of the molecule). Now only option A have this and that is why we can assume this maybe the answer and to confirm this we can read and comapre each nucleotide manuaally.

Question 62:-

The right option is option (c) one amino acid at a time

Explanation:-

During the elongation process of translation. only one tRNA can be in the P site and one in the A site. Both these tRNA carry amino acid and each tRNA have only one amino acid.

Peptide bond is formed between these two amino acids and then ribosome slide forward so that a new tRN can come.

So the step of elogation is done by one amino acid at one time with using 3 nucleotides base as one codon.

Question 63:-

The right option is option (d) the ribosomal subunits to disassociate from mRNA molecule.

Explanation:-

The role of stop codon is to stop the process of translation so it does not initiate the translation by bringing the 2 subunits together. It signals the end of the translation and it s possible because tRNA with anticodons for stop codon do not have any amino acids attach to them. This makes one site of the ribosome empty and that makes the subunits of the ribosomes to disassemble.

Question 64:-

The right option is option (b) Initiation

Explanation:-

The first step in the proesses related to cenral dogma of life (replication, transcription, translation) is the stage of initiation. Every process needs to be initiated so that they can assemble all the molecules required,

Other role of initiation is to find the site which will serve as the start point and then get it ready by like uncoiling (for DNA related processes), to assemble the proteins around that point and near it.

Question 65:-

The right option is option (d) A, P and E

Explanation:-

The three sites which are present on ribosomes are called A site, P site and E site. New Amino acids come into the A site and it is also called Aminoacyl site.

The P-site is the site whch catalyzes the formation of peptide bond and this site is also called Peptidyl site.

The E site is so called because it is the site from where tRNA exits the rbosome once the peptide transfer is done so that they can be recycled and charged with new amino acid.

Question 66:-

The right option is option (d) Substitutuon

Explanation:-

If we compare the two given sequences we can notice that the in original sequence, the codon is GAT and it is changed to TAT. Now GAT will be transcribe into CUA and it will code for Leucine and in the mutation. the codon TAT will be transcribed into AUA and it will code for isoleucine.

This changes only one amino acid sequence in the protein to be synthesized and thus it is called substitution as one amino acid is substituted by the other.