Molecular Basis of Inheritance - Online Test
Q1. The strand of DNA that forms mRNA is called
Answer : Option D
Explaination / Solution:
During transcription, only one of the two DNA strands is copied. This is called the template strand because it acts as a template for the mRNA that is being assembled by the ribosomes. The sequence of the mRNA is complementary to the sequence of the template strand.
It is also known as sense strand.
Q2. Codon is made up of
Answer : Option A
Explaination / Solution:
A codon is a sequence of three DNA or RNA nucleotides that corresponds with a specific amino acid or stop signal during protein synthesis. A codon is a triplet.
Q3. The code AUG stands for
Answer : Option B
Explaination / Solution:
The start codon is the first codon of a messenger RNA (mRNA) transcript translated by a ribosome. The start codon always codes for methionine in eukaryotes and a modified Met (fMet) in prokaryotes. The most common start codon is AUG.
Q4. Protein synthesis occurs over
Answer : Option B
Explaination / Solution:
Protein synthesis occurs over ribosomes which are also called protein factories of cell. Each ribosomes have two parts 40S and 60S in eukaryotes and 30S and 50S in prokaryotes.
Q5. Okazaki is known for his contribution to the understanding of
Answer : Option C
Explaination / Solution:
Reiji Okazaki (October 8, 1930 – August 1, 1975) was a pioneer Japanese molecular biologist, known for his research on DNA replication and especially for describing the role of Okazaki fragments along with his wife Tsuneko.
He proposed the concept of semi-conservative nature of replication of DNA molecules.
Q6. Number of nitrogenous bases in a Codon is
Answer : Option B
Explaination / Solution:
A codon is a sequence of 3 nitrogenous bases located on mRNA that will pair up with the anticodon of tRNA to make the polypeptide (protein) I. 64 codons can be obtained from four nitrogenous bases if arranged in group of 3.
Q7. All the terminator codons begin with the nucleotide of
Answer : Option A
Explaination / Solution:
Terminator codon do code for any amino acids. UAA, UAG, UGA are three codon that do not code for amino acids. All three terminator or stop codon start with U.
Q8. Whose experiments cracked the DNA and discovered unequivocally that a genetic code is a ‘‘triplet’’?
Answer : Option D
Explaination / Solution:
The Nirenberg and Matthaei experiment was a scientific experiment performed on May 15, 1961, by Marshall W. Nirenberg and his post doctoral fellow, J. Heinrich Matthaei. The experiment deciphered the first of the 64 triplet codons in the genetic code by using nucleic acid homopolymers to translate specific amino acids and discovered that genetic code is triplet
Q9. Amino acid + ATP →Aminoacyl-AMP + P–P , depicts
Answer : Option A
Explaination / Solution:
Amino acid activation refers to the attachment of an amino acid to its Transfer RNA (tRNA).
Aminoacyl transferase binds Adenosine triphosphate (ATP) to amino acid, PP is released. Aminoacyl transferase binds AMP-amino acid to tRNA. Activated amino acids combine with t-RNA.
Q10. Which one of the following is not a part of a transcription unit in DNA?
Answer : Option A
Explaination / Solution:
Transcription is the process by which the information in a strand of DNA is copied into a new molecule of messenger RNA (mRNA).
Transcription of DNA requires a promoter, the structural gene to be transcripted and a terminator. The inducer is not required during transcription of DNA.
