Chapter Exam

Chapter 5: Molecular Genetics — Online MCQ Test

Q: Which sugar is present in the backbone of DNA?

Answer: B. Deoxyribose — DNA contains deoxyribose sugar, which lacks one oxygen atom compared to ribose. This is a basic structural feature of DNA.

Q: The process by which DNA makes an identical copy of itself is called ______.

Answer: C. Replication — Replication is the copying of DNA before cell division. It ensures genetic information is passed to daughter cells.

Q: If the template DNA strand has the sequence 3'-T A C-5', what is the complementary mRNA sequence?

Answer: A. 5'-A U G-3' — During transcription, RNA nucleotides pair with the DNA template strand using uracil in place of thymine. Thus, TAC on DNA gives AUG on mRNA.

Q: During translation, the initiator tRNA first pairs with the start codon on mRNA. Which codon serves as the usual start codon?

Answer: B. AUG — AUG is the start codon in most organisms and codes for methionine. It signals the beginning of translation.

ZOOLOGY · CLASS 12th · Tamil Nadu State Board

Practice Chapter 5: Molecular Genetics with a free chapter-wise online MCQ test for Tamil Nadu State Board CLASS 12th ZOOLOGY. This chapter covers: Focusing on DNA structure and function this chapter details replication transcription translation gene regulation Human Genome Project and DNA fingerprinting techniques.. AI-generated questions from basic to board-exam level, with instant results and explanations.

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Chapter 5: Molecular Genetics — Important Questions & Answers (FAQ)

Frequently asked questions from Tamil Nadu State Board CLASS 12th ZOOLOGY — Chapter 5: Molecular Genetics, with answers and explanations. These are sample questions; the exam has its own separate question set.

Which sugar is present in the backbone of DNA?

A. Ribose
B. Deoxyribose ✓
C. Glucose
D. Fructose

Answer: B. Deoxyribose
DNA contains deoxyribose sugar, which lacks one oxygen atom compared to ribose. This is a basic structural feature of DNA.

The process by which DNA makes an identical copy of itself is called ______.

A. Transcription
B. Translation
C. Replication ✓
D. Mutation

Answer: C. Replication
Replication is the copying of DNA before cell division. It ensures genetic information is passed to daughter cells.

If the template DNA strand has the sequence 3'-T A C-5', what is the complementary mRNA sequence?

A. 5'-A U G-3' ✓
B. 5'-T A C-3'
C. 5'-U A C-3'
D. 5'-A T G-3'

Answer: A. 5'-A U G-3'
During transcription, RNA nucleotides pair with the DNA template strand using uracil in place of thymine. Thus, TAC on DNA gives AUG on mRNA.

A student observes that a DNA sample from a crime scene matches the suspect at all tested VNTR loci. What is the most appropriate conclusion?

A. The suspect is definitely guilty without any further evidence
B. The DNA profile strongly suggests the suspect may be the source, but other evidence is also needed ✓
C. The DNA sample must be RNA contamination
D. The test proves the suspect's blood group only

Answer: B. The DNA profile strongly suggests the suspect may be the source, but other evidence is also needed
A DNA fingerprint match provides strong evidence of identity, but it is not the sole basis for guilt in legal investigations. Additional evidence is needed.

During translation, the initiator tRNA first pairs with the start codon on mRNA. Which codon serves as the usual start codon?