Question 1

Which phase of the eukaryotic cell cycle is characterized by the duplication of DNA, resulting in two identical copies of each chromosome?

Accepted Answer

S phase

Question 2

During mitosis, what structure holds the two sister chromatids together until they are separated into daughter cells?

Accepted Answer

Centromere

Question 3

A scientist is analyzing a karyotype and notices an individual has three copies of chromosome 21. What condition does this indicate, and what is the total chromosome number in this individual?

Accepted Answer

Down syndrome; 47 chromosomes

Question 4

Which of the following best describes the difference between haploid and diploid cells?

Accepted Answer

Haploid cells have one set of chromosomes, while diploid cells have two sets.

Question 5

If a human somatic cell contains $$2n = 46$$ chromosomes, how many chromosomes will be present in a human gamete after meiosis?

Accepted Answer

$$23$$

Question 6

Which checkpoint in the cell cycle ensures that all chromosomes are properly attached to the spindle before the cell proceeds with division?

Accepted Answer

M checkpoint

Question 7

Artificial selection in agriculture has led to the domestication of maize from its wild ancestor teosinte. Which of the following best explains the genetic basis for this transformation?

Accepted Answer

Selective breeding favored alleles for larger, softer kernels in maize.

Question 8

A forensic scientist uses DNA evidence to identify a suspect in a criminal investigation. Which property of DNA makes this possible?

Accepted Answer

DNA contains unique sequences that vary between individuals.

Question 9

Which of the following equations correctly represents the reduction in chromosome number during meiosis?

Accepted Answer

$$2n \rightarrow n$$

Question 10

A plant breeder crosses two pea plants, one with purple flowers (PP) and one with white flowers (pp). All offspring have purple flowers. What does this demonstrate about the purple allele?

Accepted Answer

The purple allele is dominant.

Question 11

Which of the following best explains why chromosome number does not directly correlate with organismal complexity?

Accepted Answer

Chromosome number is determined by evolutionary history and chromosomal rearrangements, not complexity.

Question 12

In the context of genetics, what is an allele?

Accepted Answer

A variant form of a gene found at a specific locus on a chromosome.

Question 13

Which of the following is a real-world consequence of inbreeding, as seen in the Habsburg royal family?

Accepted Answer

Higher likelihood of inheriting recessive genetic disorders.

Question 14

A cell fails to pass the G1 checkpoint due to insufficient growth signals. What is the most likely fate of this cell?

Accepted Answer

It will enter the G0 phase and stop dividing.

Question 15

Which of the following best describes the process and outcome of mitosis?

Accepted Answer

Produces two genetically identical diploid cells.

Question 16

Which of the following is a key difference between mitosis and meiosis?

Accepted Answer

Mitosis produces diploid cells, while meiosis produces haploid cells.

Question 17

A forensic case uses genetic genealogy to identify a suspect. Which step is essential in this process?

Accepted Answer

Comparing DNA profiles to public genealogy databases.

Question 18

If a cell starts with $$2n = 8$$ chromosomes and undergoes meiosis, how many chromosomes will each resulting gamete have?

Accepted Answer

$$4$$

Question 19

Which of the following best explains why regular practice and metacognition improve long-term retention in biology students?

Accepted Answer

They help students reflect on their learning and identify gaps in knowledge.

Question 20

Which of the following is a direct application of genetics in environmental science?

Accepted Answer

Using DNA to study genetic diversity in endangered species populations.

Genetics Part 1 Study Guide: MCDB 1A

Study Guide - Practice Questions

Study Guide - Flashcards