Bio 1010 ch 8 9 and 10
Denzel was looking at onion root tip cells under the microscope in biology class. He saw one cell that had two nuclei within it. What stage of the cell cycle was this cell in?
telophase/cytokinesis
Why might a cell be prevented from proceeding through the G1 checkpoint?
There is DNA damage.
Which of the following human syndromes is a monosomy?
Turner syndrome
Which of the following does NOT describe a cancer cell?
a cell regulated by contact inhibition
Cytokinesis usually, but not always, follows mitosis. If a cell undergoes mitosis and not cytokinesis, this would result in
a cell with two nuclei.
The term tetrad refers to
two homologous chromosomes each comprised of two sister chromatids.
Losing weight can reduce an obese person's risk for cancer by up to
40%.
If a cell has 46 chromosomes at the beginning of mitosis, then at the end of anaphase there would be a total of
92 chromosomes.
Which cancer therapy can lead to side effects such as nausea and hair loss?
chemotherapy
During meiosis II,
chromosomes line up separately, with sister chromatids facing opposite spindle poles.
In an experiment, cells grown in a petri dish divided until they formed a thin single layer. When cells were removed from the middle of the dish, the cells bordering the open space began dividing until they had filled the empty space. This type of regulation is called
contact inhibition.
One major difference between meiosis I and meiosis II is that
crossing-over occurs in prophase of meiosis I but not in prophase of meiosis II.
What structure is formed by two sister chromatids being held together by a centromere?
duplicated chromosome
When during the cell cycle are chromosomes visible under a microscope?
during M phase
If you were looking under the compound light microscope at an onion root tip, in what stage of the cell cycle would the majority of the cells be?
interphase
The figure below shows a cell in which stage of the cell cycle?
interphase
In the human life cycle,
meiosis produces haploid gametes, and fertilization creates a diploid cell that divides by mitosis to produce a new individual.
The figure below shows a cell in the mitotic stage of
metaphase
For the figure shown here, indicate the correct stage of meiosis and whether the cell is haploid (n) or diploid (2n).
metaphase I, 2n
If tumor cells have a faulty, non-functional proteinase, they will be unable to undergo which of the following processes?
metastasis
The mitotic spindle is composed of________, which originate from the________.
microtubules; centrosome
Which of the following processes does not contribute to creating genetic variability in the offspring?
mitosis
The failure of sister chromatids to separate during meiosis is called
nondisjunction.
Cells that do not receive the correct signals to move from G1 into S phase will enter G0 and therefore will
not undergo mitotic division unless it later receives the go-ahead signal.
Chromatin wrapped around histones form a bead-like structure known as a
nucleosome.
Within the human life cycle, which of the following processes and products are paired correctly?
oogenesis - 1n gamete
Which of the following is a function only of mitosis?
organismal growth
Which of the following only occurs once during meiosis?
pairing of homologous chromosomes
Anushka was examining a cell under the microscope and she noticed the formation of a cell plate in the midline of the cell and the formation of nuclei at opposite poles of the cell. The cell under examination was most likely a(n)
plant cell undergoing cytokinesis.
Plant cells and animal cells differ in cytokinesis because
plant cells need to build a cell wall, while animal cells do not.
Some of the drugs used in chemotherapy work by
preventing spindle formation.
Unicellular organisms undergo mitotic division to
produce new organisms.
Telomeres function to
promote chromosomal stability.
The figure below shows a cell in the mitotic stage of
prophase
For the figure shown here, indicate the correct stage of meiosis and whether the cell is haploid (n) or diploid (2n).
prophase II, n
Which of the following represents the phases of mitosis in their proper sequence?
prophase, metaphase, anaphase, telophase
Cancer is a disorder in which some cells have lost the ability to control their
rate of cell division.
Which of the following occurs prior to prophase?
synthesis of DNA
During which stage of the cell cycle does the spindle disappear?
telophase
In each gamete following telophase II, how many copies of each gene is/are present?
1
The chances of a woman over 40 years old having a baby with Down Syndrome is
1 in 80.
Cheetahs have a diploid chromosome number of 38. At prophase I, a cheetah's cell would have how many homologous pairs?
19
At the beginning of meiosis II, a cell contains how many copies of each gene?
2
During the G1 stage of interphase, a diploid organism contains how many copies of each gene?
2
A group of cells is assayed for DNA content immediately following mitosis and is found to have an average of 10 picograms of DNA in the nucleus during G1. Those cells would have________ picograms at the end of the S phase and________ picograms at the end of G2.
20; 20
A diploid cell, at the beginning of meiosis, contains how many copies of each gene?
4
If there are 20 centromeres in a cell, how many sister chromatids are there?
40
Cells grown in a petri dish tend to divide until they form a thin layer covering the bottom of the dish. Which of the following statements explains why this occurs?
Cell division can be inhibited by the proximity of other cells.
Interphase differs from interkinesis because
DNA is duplicated during interphase, but not during interkinesis.
If a cell is inhibited during the S phase of its cycle, it will not reproduce due to lack of
DNA synthesis.
Differentiated cells, such as nerve cells, would be in which of the following stages of the cell cycle?
G0
Which of the following is mismatched?
G2 stage - mitosis begins
Which of the following pairs is correctly matched?
S phase - DNA replication
Which of the following organelles would be abundant and in close proximity to the cell plate in a plant cell undergoing cytokinesis?
Golgi apparatus
Which statement accurately describes how the genetic material is divided during meiosis I?
Homologous chromosomes separate into two different daughter cells.
Which of the following statements is correct regarding the events of the cell cycle?
Interphase consists of G1, S, and G2.
Pevita has a tumor in her ovaries. She recently underwent a series of tests and is returning to the doctor to find out the results. Which of the following would be the best news that Pevitacould receive from her doctor?
It is a benign tumor.
The drug chloral hydrate prevents elongation of microtubules. During which stage of the cell cycle would chloral hydrate be most harmful?
M phase
Nuclear division occurs during
M phase.
Which of the following statements is correct?
Meiosis involves two divisions and produces four nonidentical gametes.
Inheritance of mutant forms of some genes may lead to a predisposition to develop cancer. Which of the genes listed below takes its name from its association with an eye tumor?
RB
A tumor suppressor gene undergoes a mutation that causes it to lose its normal function. What would be the most likely result of this mutation?
The cell no longer responds to signals that cause it to stop dividing or undergo apoptosis.
Which of the following is an inaccurate statement about mitosis?
The cells arising from mitosis contain only half of the necessary genetic material.
How do the daughter cells at the end of mitosis and cytokinesis compare to their parent cell when it was in G1 of the cell cycle?
The daughter cells have the same number of chromosomes and the same amount of DNA.
A human egg with 22 chromosomes that is fertilized by a normal sperm will result in
a zygote with monosomy.
An oncogene is more likely to lead to cancer than a proto-oncogene because
an oncogene is more likely to accelerate the cell cycle.
During which phase of mitosis are the sister chromatids separated and consequently become daughter chromosomes?
anaphase
For the figure shown here, indicate the correct stage of meiosis and whether the cell is haploid (n) or diploid (2n).
anaphase I, 2n
Which of the following phase(s) separates sister chromatids into daughter chromosomes?
anaphase II and anaphase of mitosis
Which of the following would increase your risk of cancer?
avoiding a high-fiber, low-sodium diet
Telomerase normally functions in
both embryonic and adult stem cells.
Apoptosis
can be used to remove damaged or malfunctioning cells.
Translocations
can lead to cancer if they disrupt the genes that regulate the cell cycle.
An enzyme that promotes apoptosis is generally known as a(n)
caspase.
What is the structure that holds together the two sister chromatids that form a chromosome?
centromere
What structure holds two sister chromatids together?
centromere
A translocation may lead to cancer if it
disrupts control of expression of genes that regulate the cell cycle.
A mutation that causes an increase in function in a tumor suppressor gene would not likely cause cancer because a tumor suppressor protein
does not promote cell division.
During metaphase I, the homologous chromosomes align at the spindle equator with each homologue
facing opposite spindle poles.
During crossing-over,
genetic material is exchanged between nonsister chromatids, resulting in new combinations of alleles.
Following meiosis I, the daughter cells are________; following meiosis II, the daughter cells are________; and following fertilization the daughter cells are________.
haploid; haploid; diploid
The presence of which protein is required in order for chromatin to compact correctly within the nucleus?
histone
Metaphase II is more similar to metaphase of mitosis than to metaphase I because
in metaphase II, chromosomes align separately at the spindle equator.
Multicellular organisms undergo mitotic cell division to
increase the size of the organism.
Which of the following is a correct match?
separation of sister chromatids - anaphase II
A centromere holds together two
sister chromatids.
Which lifestyle choice is responsible for 90% of the cases of lung cancer among men?
smoking
The term metastasis refers to the fact that cancer cells tend to
spread.
A proto-oncogene differs from a tumor suppressor gene because a proto-oncogene
stimulates cell division in a normal cell, whereas a tumor suppressor gene inhibits cell division.
Proto-oncogenes function by
stimulating the cell cycle when appropriate signals and growth factors are present.
If a solid tumor is discovered at an early stage, which treatment method is most often used?
surgery
The G2 checkpoint prevents the cell cycle from continuing until
the DNA has finished replicating.
Cytokinesis in plants occurs as________ and in animals as________.
the Golgi apparatus produces membrane-bound vesicles filled with materials to make the cell wall; actin fibers pull the membrane inward until the two sides touch
A positive genetic test for telomerase in an adult somatic body cell, such as a fibroblast, may indicate that
the cell is cancerous.
A mutation results in a cell that no longer produces a normal protein needed for the M-phase checkpoint. Which of the following would likely be the immediate result of this mutation?
the cell would never leave metaphase
If the production of cyclins halted during the cell cycle
the cell would not proceed to the next phase of the cell cycle.
Which of the following is a characteristic of cancer cells?
the nucleus is abnormally shaped.
Cancer occurs when
the regulation of the cell cycle is lost and uncontrolled cell division occurs.
When a portion of a chromosome breaks off and attaches to a different chromosome, this is called a(n)
translocation.
A homologous pair is composed of
two chromosomes with two sister chromatids each.
