Question 1

Following S phase,a human cell would have how many pairs of sister chromatids and individual DNA molecules?

Accepted Answer

Following S phase, each of the 46 chromosomes has been replicated, resulting in 46 pairs of sister chromatids, and since each chromatid is considered an individual DNA molecule, there are 92 individual DNA molecules in total.

Question 2

A scientist wants to study histones.Histones are

Accepted Answer

Histones are proteins that are tightly bound to the double strands of DNA. They play a crucial role in the packaging of DNA into chromatin, which is the highly condensed form of DNA that is found in the nucleus of eukaryotic cells. Histones help to protect DNA from damage, regulate gene expression, and facilitate DNA replication and repair.

Question 3

You are assembling a model of a chromosome,but begin having some trouble when you get to the solenoids.If you are unable to resolve this problem,which of the following steps of chromosome structure would you be unable to achieve?

Accepted Answer

Solenoids are higher-order structures formed from nucleosomes, and they further coil to form chromatin loops. If solenoids cannot be formed, chromatin loops cannot be achieved.

Question 4

Nucleosomes are located in the

Accepted Answer

Nucleosomes are composed of DNA and histones and are located in the nucleus. They help in the packaging of DNA by wrapping it around the histones, forming a bead-like structure.

Option A is incorrect because nucleosomes are located throughout the DNA strand, not just at the ends.

Option C is incorrect because nucleosomes are not associated with the nuclear membrane.

Option D is incorrect because nucleosomes are not composed of mRNA; they are composed of DNA and histones.

Option E is incorrect because nucleolus is primarily involved in ribosome synthesis, and nucleosomes do not aid in this process.

Question 5

Chromosomes are readily visible under the microscope.

Accepted Answer

Chromosomes are most visible during the M phase of the cell cycle when they become tightly condensed and organized before cell division. Therefore, the best choice is D.

Question 6

Nuclear division in eukaryotic cells is called

Accepted Answer

Meiosis is a type of cell division that produces gametes (sex cells) with half the number of chromosomes as the parent cell. Binary fission is a type of cell division in prokaryotic (bacterial) cells. Cytokinesis is the division of the cytoplasm that occurs after nuclear division. Therefore, the correct answer is mitosis, which is the process of nuclear division that produces two genetically identical daughter cells.

Question 7

If a cell has 32 chromosomes prior to S and undergoes mitosis followed by cytokinesis,each new daughter cell will have how many chromosomes?

Accepted Answer

The number of chromosomes does not change during mitosis and cytokinesis, meaning that each new daughter cell will have the same number of chromosomes as the parent cell before S, which is 32 chromosomes. Therefore, the correct answer is B) 32.

Question 8

Cytoplasmic organelles are partitioned between two daughter cells.

Accepted Answer

Cytoplasmic organelles are partitioned between two daughter cells during cytokinesis, which occurs during the M phase of the cell cycle.

Question 9

Duplicate copy of the hereditary information is made.

Accepted Answer

During the S phase of the cell cycle, DNA replication occurs, resulting in the duplication of the hereditary information.

Question 10

All of the following phases occur during interphase of the cell cycle except

Accepted Answer

The phases of the cell cycle are G1 (gap phase 1), S (synthesis), G2 (gap phase 2), and M (mitosis). Interphase includes G1, S, and G2, but not M. Therefore, the correct answer is D.

Question 11

A cell biologist is conducting a karyotype procedure on alligator red blood cells.Exactly what does this mean?

Accepted Answer

Karyotyping involves examining and photographing chromosomes from a cell sample, usually blood cells, and arranging them according to their size, banding pattern, and homologous partners. In this case, the cell biologist is conducting a karyotype procedure on alligator red blood cells, which means they will be examining and analyzing the chromosomes from these cells.

Question 12

If the centrioles are mispositioned in the cell,a functional mitotic spindle will fail to form.In this situation,how will chromosome segregation be affected?

Accepted Answer

If the centrioles are mispositioned and a functional mitotic spindle fails to form, sister chromatids will not be divided equally among daughter cells. This is because the spindle fibers, which are responsible for separating the sister chromatids, will not be able to attach properly to the chromosomes or to pull them apart, leading to an unequal distribution of genetic material. Therefore, incorrect positioning of centrioles can result in aneuploidy, a condition where there is an abnormal number of chromosomes in the daughter cells.

Question 13

Cytokinesis occurs right after

Accepted Answer

Cytokinesis occurs during telophase, specifically, after the chromosomes have separated and the nuclear envelope starts to reform. This physical division of the cell completes the process of cell division or mitosis. Therefore, the correct answer is (E) telophase.

Question 14

The actual process of cell division in prokaryotic cells is called

Accepted Answer

The actual process of cell division in prokaryotic cells is called binary fission. This process involves the replication of DNA and the separation of the two daughter chromosomes into two separate regions of the cytoplasm, followed by the division of the cell itself into two identical daughter cells. Meiosis occurs in eukaryotic organisms and involves the reduction of chromosome number in order to produce gametes. Mitosis is also a type of cell division in eukaryotic organisms that produces identical daughter cells. Cytokinesis is the final stage of cell division in which the cytoplasm is divided and the two daughter cells are separated.

Question 15

The actual process of cell division in eukaryotic cells is called

Accepted Answer

The answer of The actual process of cell division in...

Question 16

In humans the diploid number of chromosomes is 46.The haploid number is 23.Prior to mitosis in the cell cycle,the cell is in the G₂ phase.Which of the statements is true?

Accepted Answer

In the G₂ phase, DNA replication occurs and results in the formation of two identical copies of each chromosome called sister chromatids. Therefore, the homologous chromosomes have all been copied through DNA replication and are now sister chromatids. This phase is also known as the S phase, where DNA synthesis occurs. The homologous chromosomes are not lined up on the equator or pulled to their respective poles during this phase. Additionally, the cell is still diploid or 2n, not haploid or n, which means it has two sets of chromosomes.

Question 17

As a doctor,you are examining a patient who recently experienced some liver damage as a side effect of the medication that she was taking for an unrelated medical condition.You explain to her that the liver problem may take some time to resolve as certain liver cells have a cell cycle of about

Accepted Answer

The answer of As a doctor,you are examining a patient...

Question 18

Hereditary information is partitioned equally between two daughter cells.

Accepted Answer

The letter "M" represents mitosis, which is the process by which a cell divides into two daughter cells. During mitosis, the hereditary information is equally partitioned between the two daughter cells. The other answer choices are not related to cell division or hereditary information.

Question 19

You are conducting a genetic screen using Caenorhabditis elegans embryos to isolate mutations affecting anaphase A. Therefore, you need to look for embryos in which

Accepted Answer

Anaphase A involves the movement of chromosomes (centromeres) toward the spindle poles. If centromeres do not move toward the poles, it indicates a defect in anaphase A.

Question 20

Growth of the cell;synthesis of enzymes;normal metabolism.

Accepted Answer

The G1 phase is the first stage of interphase in the cell cycle, where the cell grows, synthesizes enzymes, and carries out normal metabolism.

Quiz 10: How Cells Divide