Question 1

Which scientist's experiment provided direct evidence that DNA is the genetic material in bacteriophages?

Accepted Answer

Hershey and Chase

Question 2

A testcross between an individual heterozygous for two linked genes (A and B) and a homozygous recessive individual yields the following progeny: 40% AB, 40% ab, 10% Ab, 10% aB. What is the recombination frequency between A and B?

Accepted Answer

$$\frac{10 + 10}{100} = 0.20 or$$ $$20\%$$

Question 3

Which of the following best describes the antiparallel nature of DNA?

Accepted Answer

One strand runs 5' to 3', the other runs 3' to 5'

Question 4

If a DNA sample contains 30% adenine, what percentage of cytosine does it contain?

Accepted Answer

$$100\% - (30\% + 30\%) = 40\%$$; $$\frac{40\%}{2} = 20\%$$ cytosine

Question 5

Which of the following statements about euchromatin and heterochromatin is correct?

Accepted Answer

Euchromatin is less condensed and transcriptionally active

Question 6

A three-point testcross yields the following recombination frequencies: A-B = 12%, B-C = 8%, A-C = 20%. What is the correct order of the genes?

Accepted Answer

A - B - C

Question 7

Which enzyme is responsible for joining Okazaki fragments during DNA replication?

Accepted Answer

DNA ligase

Question 8

In a GWAS Manhattan plot, what does a tall peak at a specific chromosomal location indicate?

Accepted Answer

A region strongly associated with the trait under study

Question 9

Which of the following best explains why replication of the ends of linear chromosomes is problematic?

Accepted Answer

DNA polymerase cannot add nucleotides to the 5' end of the lagging strand

Question 10

Which of the following is a function of the 5' cap added to eukaryotic mRNA?

Accepted Answer

Facilitates ribosome binding during translation

Question 11

A DNA molecule is underwound. What type of supercoiling is induced?

Accepted Answer

Negative supercoiling

Question 12

Which RNA polymerase is responsible for transcribing mRNA in eukaryotes?

Accepted Answer

RNA polymerase II

Question 13

Which of the following best describes the wobble hypothesis?

Accepted Answer

The third base of the codon can pair with multiple bases in the anticodon

Question 14

Which of the following is NOT a function of telomeres?

Accepted Answer

Initiate transcription of genes at chromosome ends

Question 15

Which of the following best describes the function of a cis regulatory element?

Accepted Answer

A DNA sequence that regulates transcription of nearby genes

Question 16

During gel electrophoresis, which nucleic acid fragment will migrate the fastest?

Accepted Answer

The fragment with the smallest number of base pairs

Question 17

Which of the following is a ribonucleoprotein important for telomere replication?

Accepted Answer

Telomerase

Question 18

Which of the following best describes the relationship between melting temperature ($$T_m) $$and base composition in DNA?

Accepted Answer

$$T_m$$ increases with higher GC content due to stronger hydrogen bonding

Question 19

Which of the following best describes the process of RNA interference (RNAi)?

Accepted Answer

Double-stranded RNA is processed into siRNAs or miRNAs, which guide the degradation or silencing of complementary mRNA

Question 20

A DNA sequence is: 5'-ATGCGTACG-3'. What is the sequence of the complementary strand?

Accepted Answer

3'-TACGCATGC-5'

Genetic Linkage, Mapping, and Molecular Genetics: Comprehensive Study Guide

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