BIOS 1700 Chapter 11 Study Guide

A cell in Prophase I of mitosis has _______ as many copies of chromosomes than each daughter cell following cytokinesis of meiosis II. a.) four times b.) twice c.) half d.) 1/4th

four times

Which of the processes is most important for passage through the G1 cell cycle checkpoint? a.) expression of genes encoding cyclin-dependent kinases b.) activation of cyclin-dependent kinases c.) activation of DNA polymerase d.) inhibition of cyclin proteins e.) changes in membrane polarization

activation of cyclin-dependent kinases

Cell division is regulated by: a.) signals that indicate that the cell has reached a sufficient size b.) signals about the nutritional status of the cell c.) all of the above d.) signals that indicate that DNA has been replicated e.) growth factor signals

all of the above

Which one of the statements regarding the S cyclin-CDK complex is true? a.) it is responsible for the degradation of nuclear membranes. b.) it is responsible for the phosphorylation of nuclear proteins c.) it ensures that DNA is not replicated multiple times d.) it regulates the expression of histone proteins. e.) it is regulated solely by the action of p53

it ensures that DNA is not replicated multiple times

How many chromosome pairs are in a normal genome?

23

It is estimated that there are a total of 2^45 cells in the adult human body. Starting from a fertilized egg, how many cell divisions would it take to get to 2^45?

45 divisions

The second meiotic division resembles mitosis because: a.) chromosomes decondense during telophase 2 b.) daughter cells have same number of cells as parent cells c.) sister chromatids are separated during anaphase 2 to become the chromosomes of the daughter cells d.) All of the above e.) spindle microtubules attach from opposite directions to the centromere of each sister chromatid pair

All of the above

Asexual reproduction occurs in: a.) All of the choices are correct b.) unicellular eukaryotes c.) bacterial cells d.) plant cells e.) animal cells

All of the choices are correct

The most common form of hemophilia is a defect in blood clotting factor VIII, which is caused by a mutant form of a gene on the X chromosome. Boys who inherit that mutation from their mother suffer from uncontrolled bleeding. Girls carrying one copy of this mutation have near normal blood clotting. Uncommonly, a girl is born with hemophilia even though both parents have normal phenotypes. Which of the statements might explain hemophilia in a girl born to parents with normal blood clotting phenotypes? a.) Nondisjunction during egg formation resulted in her receiving no X chromosome from her mother but an X from her father; she is XO. b.) Nondisjunction during egg formation resulted in her receiving two X chromosomes from her mother and an X chromosome from her father; she is XXX. c.) A nondisjunction event in sperm production resulted in her receiving X and Y chromosomes from her father and an X from her mother; she is XXY. d.) Nondisjunction during sperm formation resulted in her receiving no sex chromosome from her father and an X chromosome from her mother; she is XO.

Nondisjunction during sperm formation resulted in her receiving no sex chromosome from her father and an X chromosome from her mother; she is XO.

A researcher is studying phases of the cell cycle in a population of cells during which there is an increase in the DNA content. This stage is most likely: a.) S phase b.) G1 Phase c.) cytokinesis d.) mitosis

S phase

Most of the cells examined during interval A have half as much DNA as those measured in interval C. Therefore, most of the cells at interval B must have been in: a.) S-Phase b.) G(1)-Phase c.) G(2)-Phase d.) M-Phase e.) G(0)-Phase

S-Phase

In what was is cytokinesis in plant cells similar to binary fission in bacterium? a.) A microtubule-like structure constricts the plasma membrane between the two nuclei to separate the daughter cells. b.) A ring of actin filaments constricts the plasma membrane between the two nuclei to separate the daughter cells. c.) cell wall material is deposited to separate the daughter cells. d.) both bacterial cells and plant cells have cell walls. e.) a motor protein slides microtubules in a contractile ring at the plasma membrane between the two nuclei to separate the daughter cells.

cell wall material is deposited to separate the daughter cells

The division of the cell's cytoplasm in a eukaryotic cell is known as: a.) mitosis b.) cell fisson c.) both cytokinesis and mitosis d.) cytokinesis

cytokinesis

Which of the statements about viruses is true? a) they are a type of prokaryotic cell b) they are the root cause of most if not all cancers c.) The Rous-sarcoma virus from chickens can carry among its normal viral genes the src gene, which can increase cell division rates. Human viruses such as the HPV can also contribute to cell division and lead to cancer. d) Human cancers have not been associated with viruses e) none of the other answers are correct. f.) viruses contain multiple genes, and each of these genes is an oncogene

none of the answers.

In meiosis, recombination occurs: a.) only during prophase I and involves exchange between chromatids of homologous chromosomes. b.) during both prophases I and II and involves exchange of chromosome fragments between all four chromatids. c.) during only prophase II and involves exchange of chromosome fragments between sister chromatids. d.) during both prophases I and II and involves exchange of chromosome fragments between sister chromatids.

only during prophase I and involves exchange between chromatids of homologous chromosomes.

A gene associated with promoting normal cell division is called: a.) a proto-oncogene or tumor suppressor b.) a proto-oncogene c.) an oncogene d.) a tumor suppressor

proto-oncogene

What process can account for the phenomenon wherein a normal XY male produces a sperm carrying two Y chromosomes? a.) first division nondisjunction b.) disjunction c.) second division nondisjunction d.) copy-number variation e.) translocation

second division nondisjunction

During meiosis I: a.) diploid cells become haploid b.) gametes are formed c.) sister chromatids are not separated d.) genetically identical daughter cells are formed

sister chromatids are not separated

Phosphorylated p53 is a protein that accumulates in the nuclei of cells that have damaged DNA where it functions to block the cell cycle and activate DNA repair. The p53 gene that encodes this protein is an example of a(n): a.) tumor suppressor b.) oncogene c.) proto-oncogene d.) protein kinase

tumor suppressor