Molecular Basis of Inheritance Chapter-Wise Test 16

Correct answer Carries: 4.

Wrong Answer Carries: -1.

What was the key finding of the Hershey and Chase experiment?

Protein is the genetic material
DNA is the genetic material
RNA is the genetic material in all organisms
Lipids play a crucial role in inheritance
2

Hershey and Chase demonstrated that DNA, not protein, is the genetic material using bacteriophages labeled with radioactive isotopes.

Which of the following statements about DNA structure is correct?

DNA is composed of amino acids.
DNA is a double-stranded molecule with antiparallel strands.
DNA contains ribose sugar.
Adenine pairs with cytosine in DNA.
2

DNA consists of two antiparallel strands forming a double helix, with complementary base pairing (A-T, G-C).

Which type of mutation results in a premature stop codon?

Missense mutation
Nonsense mutation
Silent mutation
Frameshift mutation
2

A nonsense mutation results in a premature stop codon, leading to incomplete protein synthesis.

Which of the following statements about codons is incorrect?

Each codon consists of three nucleotides.
Codons specify amino acids in protein synthesis.
Codons can be overlapping in mRNA.
A stop codon signals the end of translation.
3

The genetic code is non-overlapping, meaning codons are read sequentially.

Which of the following is a function of DNA ligase?

Joins Okazaki fragments.
Synthesizes RNA primers.
Separates DNA strands.
Removes nucleotides from DNA strands.
1

DNA ligase joins Okazaki fragments on the lagging strand by forming phosphodiester bonds.

Which of the following is incorrect about the central dogma of molecular biology?

It describes the flow of genetic information.
It states that DNA is transcribed into RNA.
It states that RNA is translated into proteins.
It includes reverse transcription as a universal process.
4

Reverse transcription (RNA to DNA) is not a universal process; it occurs in retroviruses but not in all organisms.

Which of the following correctly describes a frameshift mutation?

A mutation that replaces one amino acid with another.
A mutation that results in a premature stop codon.
A mutation that shifts the reading frame of the genetic code.
A mutation that does not affect the amino acid sequence.
3

A frameshift mutation alters the reading frame, leading to incorrect amino acid sequences.

Which of the following correctly describes a nonsense mutation?

It results in a premature stop codon.
It replaces one amino acid with another.
It does not change the amino acid sequence.
It results in an insertion or deletion of nucleotides.
1

A nonsense mutation introduces a premature stop codon, leading to an incomplete and often nonfunctional protein.

Which of the following is incorrect about post-transcriptional modifications?

A 5' cap is added to the mRNA.
Introns are removed by splicing.
A poly-A tail is added to the 5' end of mRNA.
These modifications occur in eukaryotic cells.
3

The poly-A tail is added to the 3' end of mRNA, not the 5' end.

Which molecule serves as a template for transcription?

mRNA
rRNA
DNA
tRNA
3

DNA serves as a template for the synthesis of RNA during transcription.

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