Question 1

During which phase of the cell cycle does DNA replication occur, and what is the ploidy of the cell immediately after this phase?

Accepted Answer

DNA replication occurs during the S phase, and the cell remains diploid with duplicated chromosomes.

Question 2

Which of the following best describes the role of microtubules during anaphase of mitosis?

Accepted Answer

Microtubules shorten by depolymerizing at the kinetochore, pulling sister chromatids apart.

Question 3

A researcher observes a cell with a visible cleavage furrow and actin filaments constricting the membrane. What type of cell is this most likely, and what process is occurring?

Accepted Answer

An animal cell undergoing cytokinesis.

Question 4

Which of the following statements about MPF (Maturation Promoting Factor) is correct?

Accepted Answer

MPF is a protein complex that triggers the cell's passage from G2 into mitosis.

Question 5

In meiosis, during which phase do homologous chromosomes line up at the metaphase plate, and what is the significance of this arrangement?

Accepted Answer

Metaphase I; it allows for independent assortment of maternal and paternal chromosomes.

Question 6

A geneticist is studying a trait controlled by multiple genes, each contributing to the phenotype in an additive way. Which inheritance pattern is being observed?

Accepted Answer

Polygenic inheritance

Question 7

Which of the following best explains why Mendel was fortunate in choosing pea plants for his genetic experiments?

Accepted Answer

Pea plants exhibit clear, discrete traits controlled by single genes with dominant and recessive alleles.

Question 8

A patient is diagnosed with phenylketonuria (PKU). Which of the following best describes the genetic basis and consequence of this disorder?

Accepted Answer

PKU is caused by a recessive allele leading to an inability to metabolize phenylalanine.

Question 9

Which of the following scenarios illustrates incomplete dominance?

Accepted Answer

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

Question 10

During which phase of meiosis does crossing over occur, and what is its significance?

Accepted Answer

Prophase I; it increases genetic variation by exchanging DNA between homologous chromosomes.

Question 11

Which checkpoint in the cell cycle is primarily responsible for ensuring that all chromosomes are properly attached to the spindle before anaphase begins?

Accepted Answer

M checkpoint (spindle assembly checkpoint)

Question 12

A cell is observed to have two nuclei but has not yet completed cytokinesis. Which phase has just concluded?

Accepted Answer

Telophase

Question 13

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

Accepted Answer

Genotype is the genetic makeup, while phenotype is the observable trait.

Question 14

Which of the following is true regarding the separation of sister chromatids?

Accepted Answer

Sister chromatids separate during anaphase of mitosis and anaphase II of meiosis.

Question 15

Which of the following best describes a model organism and a key reason why scientists use them?

Accepted Answer

A model organism is a species that is easy to grow, has a short generation time, and is amenable to genetic manipulation.

Question 16

Which of the following best describes the difference between cytokinesis in plant and animal cells?

Accepted Answer

Animal cells use actin and myosin to form a cleavage furrow, while plant cells build a cell plate from vesicles.

Question 17

A cell is found to be in a non-dividing state, performing its normal functions. Which phase is this cell most likely in?

Accepted Answer

G0 phase

Question 18

Which of the following best describes the process of synapsis?

Accepted Answer

The pairing of homologous chromosomes during prophase I of meiosis.

Question 19

Which of the following is an example of a gene-by-gene interaction (epistasis)?

Accepted Answer

The comb shape in chickens is determined by the interaction of two genes.

Question 20

Which of the following statements about tumor suppressors is correct?

Accepted Answer

Tumor suppressors are proteins that help prevent uncontrolled cell division.

Comprehensive Guidance for Biology 1306 Exam Study Guide (Chapters 12–14)

Study Guide - Practice Questions

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