Q: A population of 1000 individuals has 360 individuals with genotype $$AA$$, 480 with $$Aa$$, and 160 with $$aa. $$What is the frequency of allele $$A$$?

$$p = \frac{360 + 0.5 \times 480}{1000} = 0.6$$

Question 1

Which enzyme is responsible for unwinding the DNA double helix during DNA replication?

Accepted Answer

Helicase

Question 2

During DNA replication, why is the lagging strand synthesized in short fragments rather than continuously?

Accepted Answer

Because the lagging strand template runs in the 5' to 3' direction, so DNA polymerase must synthesize away from the replication fork in short segments

Question 3

Which of the following best describes Okazaki fragments?

Accepted Answer

Short segments of DNA synthesized on the lagging strand during replication

Question 4

Which of the following base pairs is correct according to the structure of DNA?

Accepted Answer

Adenine pairs with thymine, guanine pairs with cytosine

Question 5

Which of the following statements about mRNA is TRUE?

Accepted Answer

mRNA is synthesized in the nucleus and carries genetic information from DNA to the ribosome

Question 6

Which process describes the synthesis of an RNA molecule from a DNA template?

Accepted Answer

Transcription

Question 7

What is the function of tRNA during translation?

Accepted Answer

It brings specific amino acids to the ribosome based on the codon sequence of mRNA

Question 8

Which of the following is NOT a condition required for Hardy-Weinberg equilibrium?

Accepted Answer

Small population size

Question 9

A population of beetles has two alleles for shell color: G (green) and g (brown). If the frequency of G is $$p = 0.7$$ and the frequency of g is $$q = 0.3$$, what is the expected frequency of heterozygotes under Hardy-Weinberg equilibrium?

Accepted Answer

$$2pq = 0.42$$

Question 10

Which of the following is an example of a postzygotic barrier to reproduction?

Accepted Answer

Hybrid sterility

Question 11

Which of the following best describes allopatric speciation?

Accepted Answer

Speciation that occurs due to a physical barrier dividing a population

Question 12

Which of the following is a vestigial structure in humans?

Accepted Answer

The appendix

Question 13

Which of the following mechanisms can increase genetic variation in a population?

Accepted Answer

Mutation

Question 14

Which of the following is NOT a difference between DNA and RNA?

Accepted Answer

DNA is translated into protein, RNA is transcribed from protein

Question 15

Which of the following is an example of gene flow?

Accepted Answer

Individuals from one population migrate and breed with another population, introducing new alleles

Question 16

Which of the following best explains why antibiotic resistance in bacteria is considered an example of natural selection rather than artificial selection?

Accepted Answer

Bacteria with resistance survive and reproduce in the presence of antibiotics, without human intention to select for resistance

Question 17

Which of the following is the correct sequence of events in the central dogma of molecular biology?

Accepted Answer

DNA → RNA → Protein

Question 18

A population of 1000 individuals has 360 individuals with genotype $$AA$$, 480 with $$Aa$$, and 160 with $$aa. $$What is the frequency of allele $$A$$?

Accepted Answer

$$p = \frac{360 + 0.5 	imes 480}{1000} = 0.6$$

Question 19

Which of the following is a correct definition of the Biological Species Concept?

Accepted Answer

A group of populations whose members have the potential to interbreed and produce fertile offspring

Question 20

Which of the following is an example of a homologous structure?

Accepted Answer

The flipper of a whale and the arm of a human

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