Question 1

Which phase of mitosis is characterized by the alignment of chromosomes along the metaphase plate, and what is the primary function of this phase?

Accepted Answer

Metaphase; ensures chromosomes are properly attached to spindle fibers for equal segregation

Question 2

During meiosis, which event increases genetic variation among gametes?

Accepted Answer

Crossing over between homologous chromosomes during prophase I

Question 3

Which checkpoint in the cell cycle ensures that all chromosomes are properly attached to the spindle before proceeding to anaphase?

Accepted Answer

M checkpoint (spindle checkpoint)

Question 4

A cell with a chromosomal nondisjunction during meiosis II will most likely produce gametes with which of the following outcomes?

Accepted Answer

Some gametes will have an extra chromosome, and some will be missing one

Question 5

Which equation correctly represents the number of possible gamete combinations due to independent assortment, where $$n is $$the haploid number?

Accepted Answer

$$2^n$$

Question 6

Which of the following best describes the difference between sexual and asexual reproduction?

Accepted Answer

Sexual reproduction increases genetic diversity through recombination and independent assortment; asexual reproduction produces clones

Question 7

A heterozygous individual for a trait (genotype Aa) is crossed with a homozygous recessive individual (genotype aa). What is the expected phenotypic ratio in the offspring?

Accepted Answer

1 dominant : 1 recessive

Question 8

Which term describes the observable physical or biochemical characteristics of an organism, as determined by both genetic makeup and environmental influences?

Accepted Answer

Phenotype

Question 9

In a dihybrid cross between two heterozygous individuals (AaBb x AaBb), what is the expected phenotypic ratio according to Mendel's Law of Independent Assortment?

Accepted Answer

9:3:3:1

Question 10

Which of the following scenarios best illustrates incomplete dominance?

Accepted Answer

A red-flowered plant crossed with a white-flowered plant produces pink-flowered offspring

Question 11

Which chromosomal disorder is caused by nondisjunction resulting in an extra copy of chromosome 21?

Accepted Answer

Down syndrome

Question 12

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 13

Which of the following best explains Mendel's Law of Segregation?

Accepted Answer

Each individual has two alleles for each gene, which separate during gamete formation

Question 14

A woman who is a carrier for an X-linked recessive disorder marries a man who does not have the disorder. What is the probability that their son will have the disorder?

Accepted Answer

$$\frac{1}{2}$$

Question 15

Which of the following is an example of codominance?

Accepted Answer

A person with both A and B alleles expresses both blood type A and B antigens

Question 16

Which process is responsible for the separation of homologous chromosomes?

Accepted Answer

Meiosis I

Question 17

A geneticist observes that two genes are inherited together more frequently than expected by independent assortment. What is the most likely explanation?

Accepted Answer

The genes are linked and located close together on the same chromosome

Question 18

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

Accepted Answer

Genotype is the genetic makeup; phenotype is the observable traits

Question 19

A couple, both heterozygous for cystic fibrosis (an autosomal recessive disorder), are planning to have a child. What is the probability that their child will have cystic fibrosis?

Accepted Answer

$$\frac{1}{4}$$

Question 20

Which of the following is NOT a function of the G1 phase in the cell cycle?

Accepted Answer

DNA replication

Cell Division and Mendelian Genetics: Study Notes for Chapters 12-15

Study Guide - Practice Questions

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