Question 1

Which of the following best describes the role of a G protein-coupled receptor (GPCR) in cell signaling?

Accepted Answer

It transmits a signal across the plasma membrane by activating a G protein when a ligand binds.

Question 2

During apoptosis in Caenorhabditis elegans, which gene acts as a brake to prevent cell death unless the appropriate signal is received?

Accepted Answer

ced-9

Question 3

A researcher observes a cell with chromosomes aligned at the center of the cell, spindle fibers attached to kinetochores, and no nuclear envelope. Which stage of mitosis is being observed?

Accepted Answer

Metaphase

Question 4

Which of the following best explains why meiosis is referred to as 'reduction division'?

Accepted Answer

It reduces the number of chromosomes per cell by half, from diploid to haploid.

Question 5

A woman with blood type AB and a man with blood type O have a child. What are the possible blood types of their child?

Accepted Answer

A or B

Question 6

Which of the following equations correctly represents the number of possible chromosome combinations due to independent assortment in gametes, where $$n is $$the haploid number?

Accepted Answer

$$2^n$$

Question 7

A cell is observed to have a single, circular DNA molecule and divides by binary fission. Which type of organism is this most likely to be?

Accepted Answer

A prokaryotic bacterial cell

Question 8

Which of the following best describes the process and significance of crossing over during meiosis?

Accepted Answer

It occurs during prophase I, where homologous chromosomes exchange genetic material, increasing genetic variation.

Question 9

A pedigree shows a trait that appears in every generation and affects both males and females equally. Which inheritance pattern is most likely?

Accepted Answer

Autosomal dominant

Question 10

Which of the following is an example of pleiotropy?

Accepted Answer

A single gene causing multiple symptoms in sickle-cell disease, such as anemia and resistance to malaria.

Question 11

Which of the following best describes the function of protein kinases in signal transduction pathways?

Accepted Answer

They add phosphate groups to proteins, often activating or deactivating them.

Question 12

A male patient is diagnosed with Klinefelter syndrome. Which of the following karyotypes would you expect to find in his cells?

Accepted Answer

47, XXY

Question 13

Which of the following scenarios best illustrates the concept of epistasis?

Accepted Answer

A gene for pigment deposition masks the expression of a gene for pigment color in mice.

Question 14

Which of the following best explains why Down syndrome occurs?

Accepted Answer

Nondisjunction during meiosis leads to an individual with three copies of chromosome 21.

Question 15

Which of the following is true regarding the difference between chromatin and chromosomes in eukaryotic cells?

Accepted Answer

Chromatin is the less condensed form of genetic material present during interphase, while chromosomes are the highly condensed form visible during cell division.

Question 16

A cell in G2 phase of interphase has 8 picograms of DNA. How much DNA will each daughter cell have after mitosis and cytokinesis are complete?

Accepted Answer

4 picograms

Question 17

Which of the following best describes the Law of Segregation as proposed by Mendel?

Accepted Answer

Alleles for a gene separate during gamete formation so that each gamete receives only one allele.

Question 18

A signal transduction pathway often involves signal amplification. Which of the following best explains this phenomenon?

Accepted Answer

A single ligand binding event can activate many molecules of a downstream enzyme, leading to a large cellular response.

Question 19

Which of the following is a correct statement about the difference between mitosis and meiosis?

Accepted Answer

Mitosis produces two genetically identical diploid cells, while meiosis produces four genetically unique haploid cells.

Question 20

A male with hemophilia (an X-linked recessive disorder) and a female who is a carrier have a child. What is the probability that their son will have hemophilia?

Accepted Answer

$$0.5$$

Cell Communication, Cell Cycle, Meiosis, and Mendelian Genetics: Study Notes

Study Guide - Practice Questions

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