College Bio Chapter 8
DNA and histones form bead-like globules known as A) nucleosomes B) mesosomes C) nucleotides D) the chromatin network E) centrosomes
A
If tumor cells have a faulty, nonfunctional proteinase, they will be unable to undergo which of the following processes? A) metastasis B) mitosis C) apoptosis D) angiogenesis E) mutations
A
Multicellular organisms undergo mitotic cell divison to A) increase the size of the organism B) facilitate sexual reproduction C) produce gametes D) increase the variabilty of the popultion E) produce new organisms
A
Susan was examining a cell under the microscope and 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) A) plant cell undergoing cytokinesis B) dividing bacterial cell C) animal cell undergoing cytokinesis D) animal cell in the M phase of the cell cycle E) plant cell in the anaphase stage
A
The drug chloral hydrate prevents elongation of microtubules by preventing the addition of new subunits to the growing end. During which stage of mitosis would chloral hydrate be most harmful? A) prophase B) anaphase C) metaphase D) telophase E) interphase
A
Unicellular organisms undergo mitotic divison to A) produce new organisms B) produce gametes C) increase the size of the organism D) increase the genetic variability of the population E) repair damaged cells
A
What is the structure that holds together the two sister chromatids that form a chromosome? A) centromere B) nucleus C) histone D) nucleosome E) chromatin
A
5. Refer to the figure below. Differentiated cells, such as nerve cells, would be in which of the following stages of the cell cycle? A) a B) b C) c D) d E) e
B
A cell is inhibited during the S phase of its cycle. It will not reproduce due to lack of A) centriole migration B) DNA synthesis C) plasma membrane structure D) ATP availability E) centromere formation
B
A mutation results in a cell that no longer produces a normal protein kinase for the M phase checkpoint. Which of the following would likely be the immediate result of this mutation? A) The cell would prematurely enter anaphase. B) The cell would never leave metaphase. C) The cell would never enter metaphase. D) The cell would never enter prophase. E) The cell would undergo normal mitosis, but fail to enter the next G1 phase.
B
A mutation that causes an increase in function in a tumor suppressor gene would not likely cause cancer because a tumor suppressor protein A) normally promotes the cell cycle B) does not promote cell division C) normally responds to growth factors D) activates a signal transduction pathway E) inactivates growth factors
B
During which stage of the cell cycle do the chromosomes duplicate? A) Interphase; G2 B) Interphase; S C) telophose D) interphase; G1 E) prophase
B
Prophase
able to see chromosomes; break down nucleus; no order; mitosis
Binary Fission
asexual reproduction
Which of the following organelles would be abundant and in close proximity to the cell plate in a plant cell undergoing cytokinesis? A) centrioles B) lysosomes C) central vacuole D) golgi apparatus E) rough endoplasmic reticulum
D
True or false -- translocations can lead to cancer if they disrupt the genes that regulate the cell cycle
true
Chromosomes
DNA and associated proteins; 23 pairs
4. Nuclear division is represented in the figure by the letter A) a B) b C) c D) d E) e
E
7. The structures labeled "d" in the following figure are called A) non-sister chromatids B) centromeres C) spindles D) centrioles E) sister chromatids
E
A group of cells is assayed for DNA content immediately following mitosis and is found to have an average of 8 picograms of DNA per nucleus. Those cells would have ___ picograms at the end of the S phase and ___ picograms at the end of G2. A) 12; 16 B) 8; 16 C) 8;8 D) 16; 8 E) 16; 16
E
A translocation may lead to cancer if it A) activates tumor suppressor genes B) deletes the telomere of the chromosome C) affects both tumor suppressor and proto-oncogenes D) moves genes from one chromosome to another E) disrupts control of expression of genes that regulate the cell cycle
E
AN oncogene is more likely to lead to cancer than a mutant tumor suppressor gene because A) a gain of function mutation in a oncogene need only occur in one allele before it disrupts control of the cell cycle B) the mutant oncogene may inactive telomerase C) a gain of function mutation in a tumor suppressor gene can promote the cell cycle D) a loss of function mutation in an oncogene is sufficient to cause unregulated cell divison E) a gain of function mutation in an oncogene is more likely to cause the other allele to mutate
A
Nucleosome
8 histones
15. The figure below shows a cell in the mitotic stage of A) prophase B) metaphase C) anaphase D) telophase E) interphase
A
23. The figure below shows a cell in which stage of the cell cycle? A) interphase B) anaphase C) telophase D) prophase E) metaphase
A
All of the following occur during the latter stages of mitotic prophase except the A) synthesis of dna B) degradation of the nuclear envelope C) coiling of chromosomes D) formation of spindles E) division of centromeres
A
A proto-oncogene differs from a tumor supressor gene because a proto-oncogene A) stimulates mitosis in a normal cell, whereas a tumor supressor gene inhibits mitosis B) inhibits the cell cycle, whereas a tumor suppressor accelerates the cell cycle C) may cause cancer if mutated, whereas a tumor suppressor gene cannot D) promotes meiosis, whereas a tumor suppressor gene promotes mitosis E) only activates enzymes in a cell that allows metastasis
A
Causes of cancer
-checkpoints, apoptosis, telermorase, etc. don't work -drinking, smoking, sun bathing, obesity, radon, etc. -Mutations of proto-oncogenes and tumor suppressor because it promotes the cell cycle and inhibits apoptosis
How do the daughter cells at the end of mitosis and cytokinesis compare with their parent cell when it was in G1 of the cell cycle? A) the daughter cells have the same number of chromosomes and twice the amount of dna B) the daughter cells have the same number of chromosomes and the same amount of dna C) the daughter cells have the same number of chromosomes and half the amount of dna D) the daughter cells have half the amount of cytoplasm and half the amount of dna E) the daughter cells have halft the number of chromosomes and half the amount of dna
B
If there are 20 centromeres in a cell, how many chromosomes are there? A) 10 B) 20 C) 40 D) 80 E) 30
B
Proteins that are involved in the regulation of the cell cycle, and that show fluctuation in the concentration during the cell cycle, are called A) centrioles B) cyclins C) kinetochores D) proton pumps E) centromeres
B
The looping of DNA around histone proteins A) occurs when the dna is damaged and allows the cell to be destroyed through apoptosis B) condenses a large amount of dna so that it can fit into the cell C) prevents the dna from becoming kinked and breaking D) produces the characteristic helix shape of the dna E) allows the room for cellular machinery to reach all genes so they me be transcribed
B
The presence of which protein is required in order for chromatin to compact correctly within the nucleus? A) nucleosome B) histone C) myosin D) actin E) chromatid
B
The spindle serves two rolls in mitotic cell division. These are to separate the A) non-sister chromatids and then the homologous chromosomes B) sister chromatids and to elongate the cell C) sister chromatids and then the non - sister chromatids D) homologous chromosomes and then form the cleavage furrow E) sister chromatids and then form the cleavage furrow
B
What structure is formed by two sister chromatids being held together by a centromere? A) chromatin B) chromosome C) histones D) nucleosome E) dna
B
When a portion of a chromosome breaks off and attaches to a different chromosome, this is called a A) telomerase B) translocation C) jumping gene D) suppressor event E) apoptosis event
B
Which of the following is not a characteristic of cancer cells? A) travel through the bloodstream to other parts of the body B) exhibit contact inhibition C) have abnormal chromosomes D) produced by a mutation of a proto-oncogene E) stimulate the growth of blood vessels
B
6. The structure labeled "c" in the following figure is called the A) sister chromatid B) non-sister chromatid C) centromere D) centriole E) spindle
C
A protein that promotes apoptosis would be considered a(n) A) proto-oncogene B) oncogene C) tumor suppressor D) signal transduction pathway protein E) mutant tumor suppressor
C
A woman inherits a mutant BRCA1 allele from her mother. She has an increased risk of developing breast cancer because A) she still has one normal allele of the BRCA1 gene that can make up for the loss of function in the mutant allele B) some of the cells in her body are already cancerous, meaning that no further mutations are needed for a tumor to form C) a mutation in her normal BRCA1 allele may lead to cancer, whereas a normal individual would have to acquire two mutations (one in each allele) to develop cancer D) every cell in the woman's body has a copy of the mutant BRCA1 allele E) the normal BRCA1 allele is more likely to mutate than in an individual without a mutant BRCA1 allele
C
Ben 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? A) metaphase B) interphase C) telophase/cytokinesis D) anaphase E) prophase
C
Cells grown in a petri dish ten d to divide until they form a thin layer covering the bottom of the dish. Which of the following statements explains why this occurs? A) the cells become deficient in cyclin B) the cells have differentiated C) cell division can be inhibited by the proximity of other cells of the same type, a process called contact inhibition D) most cells grown in the petri dishes have gone through apoptosis E) the petri dish inhibits the cells' growth
C
Cells that do not receive the correct signals to move from G1 to S phase will enter G0 and therefor will A) never be able to undergo mitosis B) be able ot produce gametes through meiosis C) not undergo mitotic division unless it late receives the go-ahead signal D) immediately move into the mitotic phase E) stay in an undifferentiated state and become stem cells
C
Cytokinesis usually, but not always, follows mitosis. If a cell undergoes mitosis and not cytokinesis, this would result in A) feedback responses that prevent mitosis B) cells with abnormally small nuclei C) a cell with two or more nuclei D) a cell with a single large nucleus E) death of the cell line
C
Embryonic cells and cancer cells are similar because A) DNA polymerase is inactive B) telomerase is inactive C) telomerase is active D) proto-oncogenes are inactive E) RNA polymerase is inactive
C
If a cell stops at the G1 checkpoint, this is most likely due to what problem? A) the cell is cancerous b) there is no problem. the cell normally stops at the G1 checkpoint C) there is dna damage D) the chromosomes are not aligned properly E) the dna has not finished replicating
C
Inheritance of mutant forms of some genes may lead to a predisposition to develop cancer. Which of the genes listed below has not been linked to hereditary forms of cancer? A) RAS B) BRCA1 C) DScam D) RB E) RET
C
The mitotic spindle is composed of ___ and grows from the ___ toward the center of the cell A) asters; spindle equator B) centrosomes; aster C) microtubules; centrosome D) microtubules; chromatid E) microtubules; cleavage furrow
C
When during the cell cycle are chromosomes visible? A) only during the G1 phase B) only when they are being copied C) during mitosis D) only during interphase E) chromosomes are always visible
C
Which is not a correct association? A) G1 stage - cell grows in size and cell organelles increase in number B) M stage - mitosis and cytokinesis C) interphase - shortest stage of the cell cycle D) G2 stage - metabolic preparation for mtiosis E) S stage - DNA synthesis
C
While Jeff was looking under the microscope at cells in different stages of mitosis he commented on the fact that many cells were in the same stage. If you were looking under the compound light microscope at an onion root tip, what stage would the majority of the cells be in the cell cycle? A) prophase B) cytokinesis C) interphase D) anaphase E) metaphase
C
Cytokinesis
Cellular division
Anaphase
Centromere breaks down, spindle fibers get shorter and pull sister chromatids apart; 92 to 46 on each side; mitosis
13. The figure below shows a cell in the mitotic stage of A) metaphase B) telophase C) interphase D) anaphase E) prophase
D
14. The figure below shows a cell in the mitotic stage of A) prophase B) interphase C) telophase D) metaphase E) anaphase
D
A positive genetic test for telomerase indicates that A) a cell is undergoing apoptosis B) proto-oncogenes have not yet mutated C) RB is inactive D) a cell is probably cancerous E) tumor suppressors are active
D
All of the following statements are true about mitosis except? A) the cells arising from the process are genetically alike B) both sexually and asexually reproducing organisms utilize the process of mitosis C) the process of mitosis is followed by cytokinesis D) the cells arising from mitosis contain only half of the necessary genetic material E) spindle fibers are involved in the movement of chromosomes
D
Angiogenesis contributes to carcinogenesis because it A) causes apoptosis in tumor cells B) allows tumor cells to spread to other parts of the body C) causes additional mutations to occur in tumor cells D) causes blood vessels to grow into the tumor E) allows tumor cells to invade underlying tissues
D
Apoptosis A) increase the number of gamete cells B) is the process that repairs damaged DNA C) increases the number of somatic cells D) can be used to remove damaged or malfunctioning cells E) occurs as telomeres increase in length
D
Cytokinesis in plants occurs as ___ and in animals as ___. A) the centrosome produces membrane-bound vesicles filled with materials to make the cell wall; the golgi apparatus produces actin fibers to pull the membrane inward until the two sides touch B) actin fibers pull the membrane inward until the two sides touch; the golgi apparatus produces membrane-bound vesicles filled with materials to make the cell wall C) the golgi apparatus produces a cleavage furrow; actin fibers pull the membrane inward until the two sides touch D) the golgi appararus produces membrane-bound vesicles filled with materials to make the cell wall; actin fibers pull the membrane inward until the two sides touch E) actin fibers interact to make the cell wall; the cleavage furrow pulls the membrane inward until the two sides touch
D
Plant cells and animal cells differ in cytokinesis because A) plant cells divide by mitosis, while animal cells divide by meiosis B) animal cells are living, while plant cells are not C) plant cells need to build a cell wall, while animal cells built the extra cellular matrix D) plant cells need to build a cell wall, while animal cells do not E) animal cells need to build a cell membrane, while plant cells do not
D
The G2 checkpoint prevents the cell cycle from continuing until A) dna is completely replicated B) organelles have been duplicated C) damage to dna can be repaired D) dna is completely replicated and damage to dna can be repaired E) replicated dna is separated
D
What would occur in a cell if the production of cyclins halted during the cell cycle? A) organelles would not be duplicated to G1 B) the cell would enter the G0 phase C) DNA would not be replicated in the S phase D) the cell would remain in the G2 phase and would not enter into mitosis E) the cell would not complete cytokinesis
D
Which items in the following pairs are correctly matched? A) G1 phase - DNA replicaiton B) G2 phase - preparation for meiosis C) M Phase - Cell growth D) S phase - DNA replication E) G0 phases - cell growth
D
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? A) the cell loses contact inhibition even when it is not surrounded by other cells B) the cell stops dividing permanently and will never re-enter the cell cycle C) the cell cycle accelerates D) the cell cycle halts and reverses back to the G0 stage E) the cell no longer responds to signals that cause it ot stop dividing or undergo apoptosis
E
Cells grown in a petri dish tend to divide until they form a thin layer covering the bottom of the dish. If cells are removed from the middle of the dish, the cells bordering the open space will begin dividing until they have filled the empty space. What does this experiment show? A) cells continue to grow as long as there is adequate space B) when cells come into contact with other cells, they stop growing C) the controls on cell growth and division can be turned on and off D) cell division can be regulated by factors outside of the cell E) all answers are valid and correct
E
If a cell has 46 chromosomes at the beginning of mitosis, then at the end of anaphase there would be a total of A) 23 chromosomes B) 23 chromatids C) 46 chromatids D) 46 chromosomes E) 92 chromosomes
E
Some multicellular organisms, like the hydra, use asexual reproduction to produce a bud that leads to a new organism. This means that they are using A) meiosis I only to give rise to new organisms B) meiosis to create new cells that become a new organism C) binary fission to creat new cells D) mitotic division to create gametes that give rise to a new organism E) mitotic division to creat new cells that become a new organism
E
Which of the following represents the phases of mitosis in their proper sequence? A) interphase, prophase, metaphase, telophase B) prophase, metaphase, anaphase, telophase, cytokinesis C) metaphase, interphase, cytokinesis, anaphase, telophase D) anaphase, interphase, prophase, metaphase, telophase E) prophase, metaphase, anaphase, telophase
E
Which of the following statements is correct regarding the events of the cell cycle? A) dna replicates during cytokinesis B) the cells stops growing in G2 phase C) dna is duplicated during the G1 and G2 phase D) the m phase is usually the longest phase E) interphase consists of G1, S, and G2
E
True or false -- cancer cells have abnormal chromosomes because they express telomerase when they should not
False
True or false -- cancer will occur if one copy of a mutant tumor suppressor gene is inherited
False
True or false -- proto-oncogenes function by preventing cells from dividing uncontrollably
False
Three checkpoints
G1, G2, M
Three phases of interphase
G1, S, G2, G0
Checkpoint G1
Is the DNA damaged?
Mitosis
Nuclear division
G0
Stay at this step if they don't divide; don't move to S phase; interphase
Treatments of cancer
Surgery: cut it out; Radiation: spot treatment; Chemotherapy: kills both healthy and bad cells ( the ones that reproduce quickly)
S Phase
Synthesis; duplicating DNA; interphase
True or false -- stem cells that contain telomerase can be found in adults
True
Checkpoing G2
briefly halts to verify DNA synthesis
Telomere (TTAGGG - 15,000)
built in aging device; cell can divide around 70 times; gets shorter with each division
Cytokinesis in Plant cells
cell plate forms in between the two
Metaphase
chromosomes meet in the middle in a straight line; mitosis
Telophase
contractile ring begins to pinch; cleavage; new nucleus forms
Cytokinesis in animal cells
contractile ring pinches cells apart
Sister chromatids
exact copies of dna
Angiogenesis
feeding the tumor (not good)
G2
grow more, centrioles go to opposite sides; interphase
G1
growing and adding organelles; interphase
centromere
holds the sister chromatids together
Checkpoint M
makes sure promosomes are properly attached to the spindle
Benign
non. spreading
Malignant
potential to spread
Interphase
prep. for cellular division
Apoptosis
programmed cell dying
Four Phases of Mitosis
prophase; metaphase; anaphase; telophase
Histones
protein molecule that chromatin is wound around
Cyclins
proteins that increase the cell cycle
