Question 1

Which of the following best describes the difference between mitosis and meiosis in terms of genetic variation in daughter cells?

Accepted Answer

Mitosis results in genetically identical daughter cells, whereas meiosis results in daughter cells with genetic variation due to crossing over and independent assortment.

Question 2

During which phase of mitosis do sister chromatids separate and move toward opposite poles of the cell?

Accepted Answer

Anaphase

Question 3

A researcher observes a cell with a single set of chromosomes (n) and notices that homologous chromosomes are paired and crossing over is occurring. Which stage and process is the cell most likely undergoing?

Accepted Answer

Prophase I of meiosis

Question 4

A plant breeder crosses two true-breeding pea plants, one with purple flowers (PP) and one with white flowers (pp). All offspring in the F1 generation have purple flowers. If two F1 plants are crossed, what is the expected phenotypic ratio in the F2 generation?

Accepted Answer

$$3:1$$

Question 5

Which of the following mechanisms does NOT contribute to genetic variation in sexually reproducing organisms?

Accepted Answer

Replication of DNA during S phase of interphase

Question 6

A woman who is a carrier for the X-linked recessive allele for color blindness (X	extsuperscript{N}X	extsuperscript{n}) and a man with normal vision (X	extsuperscript{N}Y) have a son. What is the probability that their son will be color blind?

Accepted Answer

$$1/2$$

Question 7

Which enzyme is responsible for unwinding the DNA double helix during DNA replication?

Accepted Answer

Helicase

Question 8

A patient is diagnosed with Down Syndrome. Which chromosomal abnormality is most likely responsible for this condition?

Accepted Answer

Trisomy 21

Question 9

Which of the following statements about the genetic code is TRUE?

Accepted Answer

The genetic code is universal, meaning it is shared by almost all organisms.

Question 10

A mutation changes a codon from UAU (tyrosine) to UAA. What type of mutation has occurred?

Accepted Answer

Nonsense mutation

Question 11

Which of the following best explains why mitochondrial diseases are typically inherited from the mother?

Accepted Answer

Mitochondria are inherited from the egg cytoplasm, which comes from the mother.

Question 12

Which process is responsible for the formation of the cleavage furrow during cytokinesis in animal cells?

Accepted Answer

Constriction of the actin-myosin ring

Question 13

A cell is observed to have a Barr body. What can you infer about this cell?

Accepted Answer

It is from a female with two X chromosomes, one of which is inactivated.

Question 14

Which of the following is an example of pleiotropy?

Accepted Answer

A single gene affecting both the color and shape of a pea plant's seed.

Question 15

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

Accepted Answer

tRNA carries amino acids to the ribosome and matches its anticodon with codons on the mRNA.

Question 16

A scientist uses CRISPR to introduce a mutation into a gene. Which process is most directly affected by this technique?

Accepted Answer

The DNA sequence of the gene

Question 17

Which of the following best explains why X-linked recessive disorders are more common in males than females?

Accepted Answer

Males have only one X chromosome, so a single recessive allele will cause the disorder.

Question 18

Which of the following is a function of DNA ligase during DNA replication?

Accepted Answer

Joining Okazaki fragments on the lagging strand

Question 19

A person with the genotype IAIB for blood type has both A and B antigens on their red blood cells. This is an example of which inheritance pattern?

Accepted Answer

Codominance

Question 20

Which of the following best describes the semiconservative model of DNA replication?

Accepted Answer

Each new DNA molecule consists of one old strand and one new strand.

BIO 101 Exam 3 Study Guide: The Cell Cycle, Meiosis, Mendelian Genetics, Chromosomal Inheritance, Molecular Genetics, and Gene Expression

Study Guide - Practice Questions

Study Guide - Flashcards