Q: Which equation correctly represents the calculation of recombination frequency ($$RF) $$between two genes?

$$RF = \frac{\text{Number of recombinant offspring}}{\text{Total number of offspring}} \times 100$$

Question 1

Which of the following best describes the difference between wild type and mutant alleles?

Accepted Answer

Wild type alleles are the most common form found in a population, while mutant alleles differ from this standard sequence.

Question 2

A woman with blood type AB and a man with blood type O have a child. What are the possible blood types of their child?

Accepted Answer

A or B

Question 3

Which of the following is an example of codominance?

Accepted Answer

A person with type AB blood expressing both A and B antigens equally

Question 4

A cross between two heterozygous yellow mice (Yy) produces offspring in a 2:1 ratio of yellow to non-yellow mice. What is the most likely explanation for this ratio?

Accepted Answer

Presence of a recessive lethal allele

Question 5

Which of the following best defines pleiotropy?

Accepted Answer

A gene that affects multiple, seemingly unrelated phenotypic traits

Question 6

In a dihybrid testcross, you observe a 1:1:1:1 ratio of progeny phenotypes. What does this suggest about the genes involved?

Accepted Answer

The genes assort independently and are likely on different chromosomes.

Question 7

Which equation correctly represents the calculation of recombination frequency ($$RF) $$between two genes?

Accepted Answer

$$RF = \frac{	ext{Number of recombinant offspring}}{	ext{Total number of offspring}} 	imes 100$$

Question 8

Why is the maximum observed recombination frequency between two genes limited to 50%?

Accepted Answer

Because at 50% recombination, genes assort independently and appear unlinked.

Question 9

A geneticist maps two genes and finds a recombination frequency of 12%. What is the distance between the two genes on the chromosome?

Accepted Answer

12 centimorgans (cM)

Question 10

Which of the following statements about DNA replication is correct?

Accepted Answer

DNA replication is semiconservative, producing two double-stranded molecules each with one old and one new strand.

Question 11

Which experimental result from the Meselson-Stahl experiment supported the semiconservative model of DNA replication?

Accepted Answer

After one round of replication in $$^{14}N$$ medium, DNA showed a single intermediate density band.

Question 12

Which of the following is NOT a requirement for DNA polymerase activity?

Accepted Answer

A supply of ribonucleotide triphosphates (rNTPs)

Question 13

Which enzyme is responsible for synthesizing the RNA primer required for DNA replication in eukaryotes?

Accepted Answer

Primase

Question 14

Which of the following best describes the function of telomerase?

Accepted Answer

It adds repetitive DNA sequences to the ends of linear chromosomes.

Question 15

During transcription in prokaryotes, what is the role of the sigma ($$\sigma) $$factor?

Accepted Answer

It recognizes promoter sequences and helps RNA polymerase initiate transcription.

Question 16

Which of the following is a key difference between prokaryotic and eukaryotic promoters?

Accepted Answer

Eukaryotic promoters often have a TATA box and require multiple transcription factors, while prokaryotic promoters are recognized directly by sigma factor.

Question 17

Given the following DNA template strand: 5'-TACGGTACG-3', what is the sequence of the mRNA produced during transcription?

Accepted Answer

5'-CGUACCGUA-3'

Question 18

Which of the following is NOT a type of post-transcriptional modification in eukaryotes?

Accepted Answer

Removal of exons

Question 19

A mutation in a gene results in a protein that is only expressed in males, even though both sexes carry the gene. This is an example of:

Accepted Answer

Sex-limited trait

Question 20

Which of the following best describes alternative splicing?

Accepted Answer

The process by which different exons are joined or skipped to produce multiple mRNA variants from a single gene

Genetics Study Guide: Beyond Mendelian Genetics, Linkage & Chromosome Mapping, DNA Replication, and Transcription

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