$$\mathrm{C_6H_{12}O_6$} + 6\mathrm{O_2$} \rightarrow 6\mathrm{CO_2$} + 6\mathrm{H_2O} + \text{energy}$$

Question 1

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

Accepted Answer

Genotype is the genetic makeup of an organism, while phenotype is the observable physical or biochemical characteristics.

Question 2

In the diagram of chromosome pairs, what is the significance of the different shading and allele designations (e.g., R1, R2, B1, B2)?

Accepted Answer

They represent homologous chromosomes inherited from each parent, with different alleles at specific loci.

Question 3

If a cell has 4 chromosomes before replication, how many chromatids will be present at the metaphase plate of mitosis after DNA replication?

Accepted Answer

8 chromatids

Question 4

Which equation correctly represents the process of cellular respiration?

Accepted Answer

$$\mathrm{C_6H_{12}O_6$} + 6\mathrm{O_2$} ightarrow 6\mathrm{CO_2$} + 6\mathrm{H_2O} + 	ext{energy}$$

Question 5

What is the expected phenotypic ratio for a dihybrid cross (heterozygote x heterozygote) for two independently assorting traits?

Accepted Answer

9:3:3:1

Question 6

Which of the following statements about DNA structure is correct?

Accepted Answer

DNA strands are antiparallel, meaning one strand runs 5' to 3' and the other runs 3' to 5'.

Question 7

According to Chargaff’s Rules, if guanine makes up 22% of the bases in a DNA molecule, what percentage of the bases will be cytosine?

Accepted Answer

22%

Question 8

What is the function of the enzyme helicase during DNA replication?

Accepted Answer

It unwinds the DNA double helix.

Question 9

Which type of mutation would result if a single base is deleted from a DNA sequence?

Accepted Answer

Frameshift mutation

Question 10

What is the role of tRNA in gene expression?

Accepted Answer

It carries amino acids to the ribosome during translation.

Question 11

Which codon codes for the amino acid tryptophan (Trp) according to the genetic code chart?

Accepted Answer

UGG

Question 12

What is the main difference between mitosis and meiosis in terms of chromosome number in the resulting cells?

Accepted Answer

Mitosis produces cells with the same chromosome number as the original cell, while meiosis produces cells with half the chromosome number.

Question 13

Which of the following best explains why crossing over during meiosis increases genetic diversity?

Accepted Answer

It exchanges genetic material between homologous chromosomes, creating new allele combinations.

Question 14

What is the Central Dogma of molecular biology?

Accepted Answer

DNA is transcribed into RNA, which is then translated into protein.

Question 15

Which of the following is a real-world consequence of a nonsense mutation in a gene?

Accepted Answer

The protein is truncated and may lose its function due to an early stop codon.

Question 16

Which process is responsible for the independent assortment of chromosomes during meiosis?

Accepted Answer

Alignment of homologous chromosomes at the metaphase I plate

Question 17

If a mutation occurs in a somatic cell, will it be passed on to offspring?

Accepted Answer

No, because only mutations in gametes are passed to offspring.

Question 18

Which of the following best describes the role of restriction enzymes in DNA cloning?

Accepted Answer

They cut DNA at specific sequences, allowing insertion into vectors.

Question 19

What is the function of the sodium-potassium pump in animal cells?

Accepted Answer

It actively transports sodium out of the cell and potassium into the cell, maintaining electrochemical gradients.

Study Guide: Chromosome Structure, Dihybrid Crosses, and the Genetic Code

Study Guide - Practice Questions