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Protein Biosynthesis

Description: A questionnaire on protein biosynthesis.
Number of Questions: 15
Created by:
Tags: Codon Class XI / XII
Attempted 0/15 Correct 0 Score 0

Who received the Nobel Prize for deciphering the genetic code?

  1. Nirenberg and Khorana

  2. Gamow

  3. Heinrich Matthai

  4. Temin

  5. Crick


Correct Option: A
Explanation:

They discovered the genetic code in 1968.

Which of the following is responsible for the formation of the site responsible for protein synthesis?

  1. mRNA

  2. rRNA

  3. tRNA

  4. DNA

  5. Mitochondrion


Correct Option: B
Explanation:

It is responsible for the formation of ribosomes; the site of protein synthesis.

How many codons make the genetic code?

  1. 4

  2. 16

  3. 64

  4. 46

  5. 20


Correct Option: C
Explanation:

If nucleotides are arranged in units of three, the possible nucleotide combination will be 4 x 4 x 4 = 64 codons, which are more than sufficient for 20 amino acids.

Which was the first codon to be discovered in the genetic dictionary?

  1. GCC

  2. UGG

  3. AAA

  4. UUU

  5. UAA


Correct Option: D
Explanation:

It was the first codon to be discovered in the genetic dictionary. It codes for phenylalanine.

What do we call the sequence of nitrogenous bases in mRNA molecules which enclose the information for protein synthesis?

  1. Codon

  2. Genetic code

  3. Chromosome

  4. DNA

  5. Purine


Correct Option: B
Explanation:

It is the sequence of nucleotides or nitrogenous bases in mRNA molecules which enclose the information for protein synthesis.

What is the process of synthesis of mRNA from DNA called?

  1. Transcription

  2. Translation

  3. Transformation

  4. Teminism

  5. Transduction


Correct Option: A
Explanation:

The process of synthesis of mRNA from DNA is called transcription.

'A genetic code is degenerate.' What is meant by this statement?

  1. A genetic code is a triplet like UUU.

  2. There are no commas in the genetic code.

  3. Three codons are for amino acid serine.

  4. There are both initiation and termination codons.

  5. The codes are non-overlapping.


Correct Option: C
Explanation:

Presence of more then one codon for an amino acid is called degeneracy.

What is the function of mRNA?

  1. Formation of ribosomes acting as site for protein synthesis

  2. Transfer of activated amino acids to the site of protein synthesis

  3. To carry the genetic information of DNA into protoplasm and translate them into the language of protein

  4. To act as a carrier of hereditary material

  5. To help in rRNA synthesis


Correct Option: C
Explanation:

It is a function of mRNA.

What do we call the unidirectional flow of genetic information from DNA to RNA to protein?

  1. One gene one enzyme concept

  2. One gene one polypeptide concept

  3. Central dogma

  4. Reverse transcription

  5. Transcription


Correct Option: C
Explanation:

The central dogma in molecular biology involves the unidirectional flow of genetic information from DNA to RNA to protein.

Which enzyme causes the activation of amino acids during translation?

  1. RNA polymerase I

  2. Aminoacyl synthetase

  3. Reverse transcriptase

  4. Peptidyl transferase

  5. Amino-peptidase


Correct Option: B
Explanation:

Amino acids are activated in the presence of specific enzymes called aminoacyl synthetases to form phosphates of nitrogenous bases.

Which amino acid brings about the initiation of polypeptide chain?

  1. Uracil

  2. Alanine

  3. Cysteine

  4. Methionine

  5. Arginine


Correct Option: D
Explanation:

Initiation of polypeptide chain is always brought about by an amino acid called methionine.

Which of the following is not a step of translation?

  1. Attachment of RNA polymerase to initiation site

  2. Activation of amino acids

  3. Transfer of amino acid to tRNA

  4. Initiation of polypeptide chain

  5. Formylation of methionine


Correct Option: A
Explanation:

It causes unwinding of DNA, leading to mRNA synthesis.

What do we call the transfer of AA-tRNA complex from A-site to P-site?

  1. Transduction

  2. Transcription

  3. Translocation

  4. Translation

  5. Termination


Correct Option: C
Explanation:

The movement of AA-tRNA complex from A-site to P-site is called translocation.

Which of the following is/are termination codon(s)?

  1. AUG

  2. UGU

  3. UAA

  4. UAG, UGA

  5. Both (3) and (4)


Correct Option: E
Explanation:

All UAA, UAG and UGA are termination codons.

If the sequence of bases in DNA is TAAGCTAG, then the sequence of bases in the transcript will be

  1. AUUCGAUC

  2. UAAGCUAC

  3. TUUCGAUG

  4. CAUGGAAU

  5. GUAGCUUA


Correct Option: A
Explanation:

Bases are complementary to each other; A pairs with U, T with A, and G and C with C and G, respectively.

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