BIO Chapter 6

Replication of a cell's genetic material occurs during

s phase

what is the appropriate ploidy level of: rye grass with four sets of chromosomes

tetrploid

The G1 and G2 phases are also known as gap phases. During G1 and G2, the cell increases in both size and protein content. These phases serve as checkpoints to make sure the conditions are suitable for the next phase in the cell cycle.

g

Which of the following intervals occur during each of the two main stages of the eukaryotic cell cycle? cell division Correct label: mitosis

g

In ________, the nuclear envelopes re-form in each of the two newly formed cells.

telophase

true or false chromosomal replication produces two identical sister chromatids.

true

in the cell cycle phase this is a major checkpoint to assure the cells are ready for cell division.

G2 phase

during cytokinesis the two daughter cells are ________

seperated

in this cell cycle phase cells are resting

G0 phase

how many copies of the genome does a cell contain after the S phase of the cell cycle?

4

What purposes do crossing over and independent assortment play in cell division?

They help to add genetic diversity to daughter cells.

The research done by Soto, Sonnenschein, and Hunt reveals how chemicals could affect the production of gametes, thereby affecting the passage of genetic traits down from one generation to the next. Which of the following mechanisms are responsible for the generation of genetically diverse offspring? a. independent assortment of chromosomes during meiosis I b. independent assortment of chromosomes during meiosis II c. genetic recombination d. crossing over

a, c, d

While studying a novel drug, you begin to suspect that a chemical within it may be causing cells to become stuck at the G1 checkpoint. Which of the following would likely be true for cells affected by this drug's action? a. The cells would be of adequate size to divide. b. Chromosomes would be damaged during DNA replication. c. Cells would divide even if there weren't enough nutrients available. d. The cells would be unable to perform DNA replication.

a, d

Select only the events that occur during mitosis and place them in the correct order. a. The nuclear envelope dissolves and chromatin condenses into chromosomes. b. The nuclear envelope condenses. c. Sister chromatids are separated into individual chromosomes. d. The mitotic spindle aligns the chromosomes with the middle of the cell.

a, d, c, b

meiosis is... a. asexual b. sexual

b

what cell stage is the father ploidy level

diploid

true or false: a woman's eggs carry an exact copy of one of the chromosomes from that woman's mother or father.

false

true or false: the two cells resulting from meiosis are diploid, and they are further divided into four haploid cells.

false

what cell stage is a gamete

haploid

what cell stage is the egg ploidy level

haploid

_____________ results in the separation of homologous chromosomes, resulting in haploid cells that contain sister chromatids and setting the stage for meiosis II.

meiosis i

During which of the following phases of mitosis do replicated chromosomes line up at an invisible plane along the center of the cell?

metaphase

the human genome has an estimated 25,000 genes on 23 chromosomes that can be affected by crossing-over and assorted into gametes. Given these numbers, about how many different combinations of chromosomes may be found in the gametes?

millions

what is the appropriate ploidy level of: silk glands of the commercial silkworm, containing over a million copies of the genome

polyploid

The nuclear envelope breaks down during which phase of mitosis?

prophase

what phases does crossing over occur?

prophase 1 of meiosis

Which of the following explains why a cell might undergo meiosis?

to produce egg and sperm cells

Soto and Shonnenschein finally identified nonylphenol in the flasks they were using. Nonylphenol can do which of the following? Correct Answer(s) interfere with the G0/G1 checkpoint activate mitotic division

x

chromosomes cross-over a. mitosis b. binary fission c. meiosis

c

produces genetically diverse a. mitosis b. binary fission c. meiosis

c

what cell stage is the sperm ploidy level

haploid

_____________and _____________ both lead to the separation of sister chromatids

mitosis; meiosis ii

Which of the following choices states a correct reason why the process of cell division is different for prokaryotic than for eukaryotic cells?

Prokaryotes have a circular DNA molecule.

based on your knowledge of ploidy level in various human cells, would you expect human stem cells to be diploid or haploid?

diploid

what is the appropriate ploidy level of: a bacterium with a single circular chromosome

haploid

in this cell cycle phase, the nuclear DNA is divided

mitosis

while studying a newly discovered eukaryote, you notice that the organism is diploid and has 8 chromosomes. At the end of S phase, how many homologous chromosomes and sister chromatids would you expect to find in the organism?

4 homologous chromosome pairs and 16 sister chromatids in total

In the _____________ phase, the cell grows in size in preparation for DNA replication. Some chemicals prevent tumor proliferation by causing them to remain in the _____________ phase.

G1

Which of the following statements about cell division is correct?

It is the process by which organisms grow and maintain their tissues.

The most important characteristic that distinguishes meiosis from mitosis is a. the total number of chromosomes present in daughter cells. b. the number of times that S phase occurs prior to cell division. c. whether the chromosomes are duplicated at the end of cell division.

a

What organism is likely to have the least complicated form of cell division out of a shelf mushroom, a flowering oak tree, a disease-causing bacterium, or a grizzly bear?

a disease-causing bacterium

phase where chromosomes don't cross-over a. mitosis b. binary fission c. meiosis

a, b

produces genetically identical daughter cells a. mitosis b. binary fission c. meiosis

a, b

Which of the following would be checked by the cell during the checkpoint at the end of the G1 phase? a. that the cell is large enough b. that the DNA is undamaged c. that DNA replication is complete d. that there are enough nutrients available

a, b, d

During crossing over, a. neighboring daughter cells fuse together to mix genetic information. b. chromosomes leave the nucleus and "cross over" into the cytoplasm. c. replicated chromosomes transition from S phase to G2 phase. d. homologous chromosomes exchange genetic information.

d

Which of the following factors might cause a cell to pause in a phase of the cell cycle? a. having too many nutrients b. exiting G0 phase c. chromosomes lining up in the center of the cell d. damage to DNA

d

what cell stage is the mother ploidy level

diploid

what is the appropriate ploidy level of: a human cheek cell

diploid

In humans, cells containing two copies of each of the 23 chromosomes are called ___________. One copy is from the mother, and one is from the father. These two copies are ___________ to each other. After the S phase and DNA replication, each chromosome consists of two sister chromatids. These two chromatids are ___________ to each other and are linked at the ___________, so the chromosomes are shaped like an X.

diploid; homologus; identical; centromere

in this cell cycle phase the cell has grown i size in preparation for DNA replication

end of the G1 phase

Which of the following intervals occur during each of the two main stages of the eukaryotic cell cycle? interphase Correct label: G2 phase Correct label: G1 phase Correct label: S phase

g

The form of eukaryotic cell division that produces two genetically identical cells is

mitosis.

_____________ results in diploid cells and _____________ results in haploid gametes.

mitosis; meiosis

the chemicals nonylphenol and BPA both disrupt cell cycles resulting in chromosomal abnormalities. Under normal conditions, each round of mitosis should result in two identical daughter cells. If you were to observe a cell containing 3 pairs of homologous chromosomes during a normal cell cycle, how many sister chromatids would you expect to find when mitosis begins?

12 sister chromatids

researchers Ana Soto and Carlos Sonnenschein discovered breast cells multiplying in the absence of the required chemical estrogen because the plastic tubes that held the breast cells were contaminated by an endocrine disrupter. Similarly, another researcher, Dr. Patricia Hunt, discovered that female mice who drank from damaged plastic bottles ingested bisphenol A (BPA), which led to egg abnormalities. All of these troubling results were caused by disruptions of the normal cell cycle in those animals by chemical contamination from plastics. Which of the following statements are correct about the normal cell cycle?

The S phase is required to replicate the chromosomes in the cell. Some cells enter G0 phase after cell division. The G1 and G2 phases allow the cell to check whether or not it is ready to divide.

most women have their cervical cells screened as part of their routine pap exam. The doctor looks at the cervical cells to determine if they appear normal or are abnormal. Which of the following could signify an abnormal cell?

change in shape, change in size, and arrest of normal functions

__________ are points in the cell cycle where cells stop to assess their progression

checkpoints

which process contributes to genetic variation through the exchange of DNA between nonsister chromatids during prophase I of meiosis?

crossing-over

Which process divides the cytoplasm of cells following mitosis?

cytokinesis

in this cell cycle phase each daughter cell has received genetically identical DNA

cytokinesis

the human genome has an estimated 25,000 genes on 23 chromosomes that can be affected by crossing-over and assorted into gametes. These gametes can then randomly combine into a diploid cell during fertilization. Given these numbers, about how many different combinations of chromosomes could be found in diploid offspring?

trillions

true or false: although there is a one in 4 million chance that all of the chromosomes in one parent could come entirely from one grandparent, chances are high that grandchildren will recieve a mix of chromosomes from both maternal and both paternal grandparents.

true

in humans, after telophase I and cytokinesis I in meiosis, how many chromatids are present in each of the resulting cells?

46

To be described as clones the daughter cells must ?

Contain a set of DNA that is identical to that of the parent cell

DNA replication occurs in this cell cycle phase

S phase

binary fission is... a. asexual b. sexual

a

The second division of meiosis is essentially a. the repeat of the first division of meiosis. b. a way to turn haploid cells into diploid cells. c. mitosis that begins with two haploid cells and ends with four haploid cells. d. mitosis that begins with two diploid cells and ends with four diploid cells.

c

Sister chromatids are held together at a region called the

centromere

a new drug has been discovered that prevents the centromere from being divided between two cells. Which step of meiosis would be affected and why? a. anaphase I, because the mitotic spindle would be unable to pull the sister chromatids apart b. anaphase I, because the mitotic spindle would be unable to align the chromosomes at the middle of the cell c. aphase II, because the mitotic spindle would be unable to pull the sister chromatids apart

c

while studying a newly discovered prokaryotic organism, you notice that it uses binary fission to multiply. Based on your knowledge of the structures and processes of eukaryotes and prokaryotes, predict how this form of division would differ from mitosis and meiosis. a. unlike mitosis and meiosis, binary fission holds the nucleus intact. b. unlike in mitosis and meiosis, the mitotic fibers bind to a circular chromosome instead of a linear one. c. unlike in meiosis, the resulting cells will contain two copies of the chromosome. d. unlike mitosis and meiosis, binary fission requires fewer resources and less energy.

d