Question 1

Which of the following best describes the difference between a gene and an allele?

Accepted Answer

A gene is a segment of DNA that codes for a protein, while an allele is a variant form of that gene.

Question 2

During which stage of mitosis do sister chromatids separate and move toward opposite poles?

Accepted Answer

Anaphase

Question 3

A scientist is studying the effect of a new fertilizer on plant growth. Which of the following is the best example of an independent variable in this experiment?

Accepted Answer

The amount of fertilizer applied to each plant

Question 4

Which of the following statements about DNA replication in prokaryotes is correct?

Accepted Answer

DNA replication begins at a single origin and proceeds bidirectionally around the circular chromosome.

Question 5

Which of the following best explains the function of a promoter in gene expression?

Accepted Answer

It is a DNA sequence where RNA polymerase binds to initiate transcription.

Question 6

A mutation changes the third base of a codon from G to A. Which of the following best describes the possible effect of this mutation?

Accepted Answer

It may result in a silent mutation due to the redundancy of the genetic code.

Question 7

Which of the following best describes the difference between PCR (Polymerase Chain Reaction) and DNA replication in cells?

Accepted Answer

PCR uses heat to separate DNA strands, while cells use helicase enzymes.

Question 8

If a diploid organism has a genotype AaBb, what are the possible gametes it can produce, assuming independent assortment?

Accepted Answer

AB, Ab, aB, ab

Question 9

Which of the following best describes the role of tRNA during translation?

Accepted Answer

tRNA brings specific amino acids to the ribosome based on codon-anticodon pairing.

Question 10

A researcher uses gel electrophoresis to analyze PCR products. Which of the following best explains how DNA fragments are separated in this technique?

Accepted Answer

DNA fragments are separated based on size, with smaller fragments moving farther through the gel.

Question 11

Which of the following is a correct statement about the central dogma of molecular biology?

Accepted Answer

Genetic information flows from DNA to RNA to protein.

Question 12

Which of the following best describes the function of a control in a scientific experiment?

Accepted Answer

It provides a baseline for comparison to determine the effect of the independent variable.

Question 13

A pedigree shows a trait that appears in every generation and affects both males and females equally. What is the most likely mode of inheritance?

Accepted Answer

Autosomal dominant

Question 14

Which of the following best explains why mRNA must be processed before leaving the nucleus in eukaryotic cells?

Accepted Answer

To remove introns and add a 5' cap and poly-A tail for stability and translation.

Question 15

Which of the following equations correctly represents the Hardy-Weinberg equilibrium for two alleles, $$p$$ and $$q$$?

Accepted Answer

$$p^2 + 2pq$$ + $$q^2 = 1$

Question 16

A DNA molecule is replicated in a test tube using PCR. Which enzyme is replaced by heat in this process?

Accepted Answer

Helicase

Question 17

Which of the following best describes the difference between leading and lagging strand synthesis during DNA replication?

Accepted Answer

The leading strand is synthesized continuously, while the lagging strand is synthesized in short fragments called Okazaki fragments.

Question 18

Which of the following best explains why controls are important in molecular experiments such as RT-PCR?

Accepted Answer

They help distinguish between true positive results and artifacts or contamination.

Question 19

A mutation in the promoter region of a gene most likely affects which process?

Accepted Answer

Transcription initiation

Question 20

Which of the following best describes the relationship between genotype and phenotype?

Accepted Answer

Genotype refers to the genetic makeup, while phenotype is the observable traits resulting from the genotype and environment.

General Biology Exam Objectives and Study Strategies

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