Title: Cell Division
Course: Question Banks

Q: What is the difference between autosomes and sex chromosomes?
- There is no difference between the two. Autosomes are the scientific name, while sex chromosomes are the more popular name. (Incorrect. There are definite differences between the two types of chromosomes.)
- Autosomes are present in all living cells, but sex chromosomes are only present during the chromatin state of the haploid cycle. (Incorrect. Chromosomes are not associated only with specific stages of an organism’s life cycle.)
- Autosomes are matched pairs, meaning there are two copies. Sex chromosomes are really just one pair which may or may not be matched. (Correct. Autosomes and sex chromosomes contain different genes but not all genes on sex chromosomes are associated only with sexual features, and vice versa.)
A: Autosomes are matched pairs, meaning there are two copies. Sex chromosomes are really just one pair which may or may not be matched.

Q: Paired chromosomes inside the nucleus of cell indicate the organism is ________.
- haploid (Incorrect. Haploid organisms have only a single copy of each chromosome.)
- polyploid (Incorrect. “Poly” means many; polyploid organisms contain multiple copies of each chromosomes.)
- diploid (Correct. “Di” indicates there are two copies of, or paired, chromosomes.)
A: diploid

Q: Select the statements below that describe the chromosomes of the human body.
- Sex chromosomes for men are depicted by XX. (Incorrect. Human males are XY.)
- Gametes contain only sex chromosomes. (Incorrect. Gametes have all the chromosomes of an organism; they just have half the number of copies.)
- Each body cell contains 2 sets of 23 chromosomes. (Correct. Human cells contains two copies of each of the 22 autosomes and then a ‘pair’ of sex chromosomes.)
A: Each body cell contains 2 sets of 23 chromosomes.

Q: In humans ________ are haploid cells.
- muscle (Incorrect. Muscle cells are somatic (diploid) cells.)
- testes (Incorrect. Testes are involved in reproduction but are still somatic (diploid) cells.)
- sperm (Correct. Sperm cells are haploid cells so when one combines with a haploid egg, the resulting zygote is diploid.)
A: sperm

Q: DNA condenses inside cells by compacting around ________.
- centromeres (Incorrect. Centromeres are part of the microtubule-organizing center in animal cells. They do not play a role in DNA condensation.)
- cohesins (Incorrect. Cohesins are associated with sister chromatids during cell division only.)
- histones (Correct. DNA wraps around histone to create a compact, and protected, structure.)
A: histones

Q: Which type of DNA packing is the least complex?
- Chromatin (Incorrect. Chromatin is the level of organization after a nucleosome.)
- Chromosome (Incorrect. A chromosome is the most complex structure.)
- Nucleosome (Correct. Nucleosomes are the first level of organization after DNA has wrapped around histones.)
A: Nucleosome

Q: A ________ is formed from beadlike histone-DNA complexes.
- chromatin (Incorrect. Chromatin is coiled beadlike histone-DNA fibers.)
- chromosome (Incorrect. A chromosome is a very complex structure from compacted and organized histone-DNA chromatin fibers.)
- nucleosome (Correct. Nucleosomes are the first level of organization after DNA has wrapped around histones and looks like beads on a string.)
A: nucleosome

Q: Chromosomes are duplicated during what portion of the cell cycle?
- G phase (Incorrect. The G phase is ‘everyday life’ for a cell.)
- M phase (Incorrect. Chromosomes must already be duplicated before M phase.)
- S phase (Correct. “S” indicates synthesis (duplication) of DNA.)
A: S phase

Q: During G_2 phase, the cell ________.
- accumulates the building blocks of chromosomal DNA (Incorrect. This would be G1 phase.)
- undergoes DNA replication by forming sister chromatids (Incorrect. This occurs during S phase.)
- undergoes the final preparation for cell division (Correct. During G2 phase the cell replenishes energy stores and synthesizes proteins to manipulate DNA during cell division.)
A: undergoes the final preparation for cell division

Q: During the ________ phase, the cell accumulates building blocks and energy resources to copy its genome.
- S (Incorrect. This is when DNA is duplicated.)
- G_2 (Incorrect. During G2 phase the cell replenishes energy stores and synthesizes proteins to manipulate DNA during cell division.)
- G_1 (Correct. This is the major hallmark of the G1 phase.)
A: G_1

Q: During G_1 phase, the cell ________.
- undergoes DNA replication by forming sister chromatids (Incorrect. This is S phase.)
- undergoes the final preparation for cell division (Incorrect. This would be G2 phase.)
- accumulates building blocks and energy resources to copy its genome (Correct. This is the major hallmark of the G1 phase.)
A: accumulates building blocks and energy resources to copy its genome

Q: In which stage of mitosis are the chromosomes are all aligned in the center of the cell?
- prophase (Incorrect. During prophase chromosomes are not fully attached to the spindle so cannot have been lined up at the center of the cell.)
- prometaphase (Incorrect. During prometaphase chromosomes have just begun moving to the cell’s center line.)
- metaphase (Correct. During metaphase the push/pull of the mitotic spindle has balanced out with all chromosomes aligned at the cell’s midline.)
A: metaphase

Q: Which description below matches the occurrence of anaphase?
- Chromosomes condense and become visible, nuclear envelope breaks down and nucleolus disappears. (Incorrect. This would be prophase.)
- Chromosomes line up, the mitotic spindle is fully developed, and centrosomes are at opposite poles. (Incorrect. This would be metaphase.)
- Sister chromosomes are pulled toward opposite poles. Non-kinetochore spindle fibers lengthen and elongate the cell. (Correct. Sister chromatids separate into distinct chromosomes in anaphase and begin moving to opposite poles in the dividing cell.)
A: Sister chromosomes are pulled toward opposite poles. Non-kinetochore spindle fibers lengthen and elongate the cell.

Q: ________ is the first stage of mitosis.
- Anaphase (Incorrect. Anaphase is the fourth stage of mitosis.)
- Metaphase (Incorrect. Metaphase is the third stage of mitosis.)
- Prophase (Correct. Prophase is the first stage of mitosis.)
A: Prophase

Q: Which option describes the final stage of karyokinesis?
- Chromosomes are all aligned in the center of the cell. (Incorrect. This is metaphase, the "change phase.")
- Chromosomes have been separated in half and are retreating to opposite sides of the cell. (Incorrect. This is anaphase, the "upward phase.")
- Nuclei are beginning to form, but there is still just one cell (Correct. This describes telophase, which is the final stage of karyokinesis when there is still just one cell.)
A: Nuclei are beginning to form, but there is still just one cell

Q: Mitotic spindle microtubules connect to ________ during prometaphase.
- condensin (Incorrect. Condensin holds together sister chromatids.)
- centrioles (Incorrect. Centrioles are part of the microtubule-organizing center that radiates mitotic spindle microtubules.)
- kinetochores (Correct. Kinetochores on the centromeres of chromosomes are the attachment points of mitotic spindle microtubules.)
A: kinetochores

Q: The polar microtubules ________.
- aid in spindle orientation (Incorrect. Astral microtubules anchor the spindle poles to the cell membrane.)
- connect to kinetochores during prometaphase (Incorrect. Spindle microtubules connect to kinetochores during prometaphase.)
- contribute to cell elongation during mitosis. (Correct. Polar microtubules overlap at the metaphase plate and push the chromosomes apart as they elongate the cell.)
A: contribute to cell elongation during mitosis.

Q: Cell division is not complete until ________, the physical separation of the daughter cells, occurs.
- cleavage (Incorrect. Cleavage is not the general term for the physical separation of daughter cells.)
- splitting (Incorrect. Splitting is not the term for the physical separation of daughter cells.)
- cytokinesis (Correct. Cytokinesis is the physical separation of daughter cells.)
A: cytokinesis

Q: In animal cells, cytokinesis occurs ________.
- after telophase ends (Incorrect. Cytokinesis and telophase are mostly concurrent.)
- concurrently with telophase, but with telophase beginning first (Incorrect. Cytokinesis actually begins after anaphase starts; it proceeds concurrently with telophase though.)
- concurrently with telophase, but with cytokinesis beginning first (Correct. Cytokinesis actually begins after anaphase starts; it proceeds concurrently with telophase though.)
A: concurrently with telophase, but with cytokinesis beginning first

Q: The structure that gives rise to the cell plate in plant cells is called a ________.
- cleavage furrow (Incorrect. Animal cells use a cleavage furrow.)
- contractile plate (Incorrect. There is not contractile plate in plant cell divisions.)
- phragmoplast (Correct. The phragmoplast is a vesicular structure that becomes a cell plate.)
A: phragmoplast

Q: What is the main prerequisite for clearance at the G_2 checkpoint?
- Cell has reached a sufficient size (Incorrect. Cell size is a factor in the G_1 checkpoint.)
- An adequate stockpile of nucleotides (Incorrect. Nucleotide stockpiles are checked during the G_1 checkpoint.)
- Proper DNA replication (Correct. The G_2 checkpoint verifies all the DNA replicated correctly during S phase.)
A: Proper DNA replication

Q: The ________ checkpoint confirms all kinetochores are attached to a spindle fiber.
- G_1 (Incorrect. Sister chromatids have not formed by the G_1 checkpoint.)
- G_2 (Incorrect. Kinetochore attachment is not verified for the G_2 checkpoint.)
- M checkpoint (Correct. Kinetochore attachment to spindle fibers is confirmed at the M checkpoint.)
A: M checkpoint

Q: The initiation signal for triggering cell division is ________.
- the M checkpoint (Incorrect. The M checkpoint occurs during cell division.)
- any interphase checkpoint (Incorrect. Checkpoints involved in cell division cannot serve as an initiation signal.)
- an external event (Correct. An external event is responsible for triggering (and inhibiting) cell division.)
A: an external event

Q: Crowding of cells may ________.
- increase the rate of cell division (Incorrect. Crowding does not increase the rate of cell division.)
- increase the chance of mutated daughter cells (Incorrect. Crowding does not increase the chance of mutations.)
- inhibit a cell from beginning division (Correct. Crowding can prevent a cell from beginning division.)
A: inhibit a cell from beginning division

Q: A change in composition of which of these molecules causes a cell to become cancerous?
- Protein (Incorrect. Protein changes will not generate cancerous cell growth.)
- Carbohydrate (Incorrect. Carbohydrate changes will not generate cancerous cell growth.)
- DNA (Correct. Mutations in DNA can cause a cell to become cancerous.)
A: DNA

Q: In order for cancer to develop, a ________ would need to be inactivated.
- proto-oncogene (Incorrect. Inactivating a proto-oncogene would actually slow cell division and growth.)
- oncogene (Incorrect. Inactivating an oncogene would prevent cancerous cell growth and division.)
- tumor suppressor gene (Correct. A tumor suppressor gene will prevent cancerous cell growth, so it needs to be removed for cancer to develop.)
A: tumor suppressor gene

Q: Scientists believe ________ is common in organisms because it increases genetic variation.
- asexual reproduction (Incorrect. Asexual reproduction does not increase genetic variation: it generates clones.)
- mutation (Incorrect. While mutation does increase genetic variation, it is either a defective process or a random accident.)
- sexual reproduction (Correct. Sexual reproduction allows for new, unique genetic combinations in offspring.)
A: sexual reproduction

Q: Most animals utilize a(n) ________ life strategy.
- alternation of generations (Incorrect. Alternation of generations is the life strategy of plants.)
- haploid-dominant (Incorrect. Fungi and some algae lead haploid-dominant lives.)
- diploid-dominant (Correct. Most animals spend their lives as diploid-dominant forms.)
A: diploid-dominant

Q: ________ utilize a diploid-dominant life strategy.
- Most plants (Incorrect. Alternation of generations is the life strategy of plants.)
- Most fungi (Incorrect. Fungi and some algae lead haploid-dominant lives.)
- Most animals (Correct. Most animals spend their lives as diploid-dominant forms.)
A: Most animals

Q: Plants utilize a(n) ________ life strategy.
- haploid-dominant (Incorrect. Fungi and some algae lead haploid-dominant lives.)
- diploid-dominant (Incorrect. Most animals spend their lives as diploid-dominant forms.)
- alternation of generations (Correct. Alternation of generations is the life strategy of plants.)
A: alternation of generations

Q: Even though the processes are very similar, mitosis and meiosis are two very distinct processes. What is the difference between meiosis and mitosis?
- Mitosis only occurs in plants and single cell organisms, while meiosis only occurs in animals. (Incorrect. Mitosis occurs in all types of organisms,while meiosis only occurs in sexually reproducing organisms.)
- Mitosis starts with diploid but results in haploid cells, while meiosis results in two identical sister cells genetically identical to the original parent cell. (Incorrect. These are not the products of mitosis or meiosis.)
- Mitosis results in two identical sister cells genetically identical to the original parent cell, while meiosis also starts with diploid but results in haploid cells. (Correct. Mitosis results in identical daughter cells, while meiosis generates haploid cells from diploid.)
A: Mitosis results in two identical sister cells genetically identical to the original parent cell, while meiosis also starts with diploid but results in haploid cells.

Q: Meiosis is divided into ________ round(s) of division.
- 1 (Incorrect. Mitosis has only a single round of division.)
- 3 (Incorrect. Meiosis does not have three rounds of division.)
- 2 (Correct. Meiosis has two rounds of division with no DNA duplication between the rounds.)
A: 2

Q: At the end of success meiosis, daughter cells are ________ and the parent cell was ________.
- 2n, n (Incorrect. Daughter cells are not 2n.)
- 2n, 2n (Incorrect. Daughter cells are not 2n.)
- n, 2n (Correct. Daughter cells from meiosis are haploid while the parent was diploid.)
A: n, 2n

Q: Most of the typical events of ________ may not occur during meiosis I.
- cytokinesis (Incorrect. Complete cytokinesis must occur at the end of meiosis I to generate two daughter cells that still need to divide again.)
- prophase (Incorrect. Prophase I of meiosis I still has many steps that must be completed.)
- telophase (Correct. Telophase I of meiosis I may not occur or is very limited compared to telophase in mitosis.)
A: telophase

Q: A key event that occurs in meiosis is ________.
- crossing over during meiotic interphase (Incorrect. There is no crossing over in meiotic interphase (or really even a meiotic interphase).)
- crossing under during meiosis II (Incorrect. There is no crossing over in meiosis II.)
- crossing over during meiosis I (Correct. Crossing over during meiosis I is a key feature and process that generates genetic diversity in offspring.)
A: crossing over during meiosis I

Q: During ________, homologous chromosomes are separated.
- anaphase II (Incorrect. Homologous chromosomes must be separated before anaphase II.)
- both anaphase I and anaphase II (Incorrect. Homologous chromosomes must be separated before anaphase II.)
- anaphase I (Correct. Homologous chromosomes must be separated during meiosis I and this occurs during anaphase I.)
A: anaphase I

Q: The end products of meiosis I are ________ cells.
- 2 diploid (Incorrect. The results of meiosis I are not diploid cells.)
- 4 haploid (Incorrect. Meiosis does not yield 4 cells until after meiosis II.)
- 2 haploid (Correct. Meiosis I results in 2 haploid daughter cells.)
A: 2 haploid

Q: The part of meiosis that is similar to mitosis is ________.
- meiosis I (Incorrect. Meiosis I is less similar to mitosis.)
- telophase I (Incorrect. Telophase I may not even occur in some meiotic divisions.)
- meiosis II (Correct. The process of meiosis II is more similar to mitosis than meiosis I is.)
A: meiosis II

Q: At which stage of meiosis are sister chromatids separated from each other?
- anaphase I (Incorrect. Homologous chromosomes are separated during anaphase I, not sister chromatids.)
- telophase II (Incorrect. Chromatids must have already separated before telophase II.)
- anaphase II (Correct. Sister chromatids separated into single stranded chromosomes during anaphase II.)
A: anaphase II

Q: The end products of meiosis II are ________ cells.
- 2 diploid (Incorrect. Meiosis II does not result in diploid cells.)
- 2 haploid (Incorrect. Meiosis II does not result in two cells.)
- 4 haploid (Correct. Meiosis II generates 4 haploid cells from a single diploid cell.)
A: 4 haploid

Q: One of the most important results of ________ is genetically unique cells.
- mitosis (Incorrect. Mitosis generates genetically identical cells.)
- both meiosis and mitosis (Incorrect. Mitosis generates genetically identical cells.)
- meiosis (Correct. Meiosis generates genetically unique cells.)
A: meiosis

Q: Genetic variation from meiosis is generated during ________.
- meiosis II (Incorrect. Genetic variation has already been generated before meiosis II.)
- both meiosis I and meiosis II (Incorrect. Genetic variation has already been generated before meiosis II.)
- meiosis I (Correct. Both crossing over during prophase I and the random alignment of homologous chromosomes in metaphase I generate genetic variation.)
A: meiosis I

Q: ________ is heavily influenced by the species’s genetic variation.
- An individual’s short-term survival (Incorrect. Species’ genetic variation does not play a large role in survival of an individual.)
- A population’s short-term survival (Incorrect. Genetic variation at the species level has less of an impact on short-term survival of populations, though it can play a role.)
- A population’s long-term survival (Correct. Genetic variation directly impacts the ability of a species, and population, to survive long term.)
A: A population’s long-term survival

Q: ________ chromosomes contain fragments of DNA exchanged between homologues.
- Jumbled (Incorrect. There are no jumbled chromosomes.)
- Mosaic (Incorrect. Chromosomes are not typically referred to a mosaic.)
- Recombinant (Correct. Recombinant chromosomes contain fragments of DNA exchanged between homologues during crossing over.)
A: Recombinant

Q: Recombinant chromosomes contain ________.
- fragments of RNA exchanged between gametes (Incorrect. RNA is not exchanged between gametes.)
- fragments of DNA exchanged between gametes (Incorrect. Fragments of DNA are not exchanged between gametes.)
- fragments of DNA exchanged between homologues (Correct. Recombinant chromosomes contain fragments of DNA exchanged between homologues during crossing over.)
A: fragments of DNA exchanged between homologues

Q: Identify the mechanism that ensure offspring are genetically different from parents and siblings.
- Nonrandom division of the maternal and paternal genomes (Incorrect. Nonrandom division of genomes would not generate genetic differences.)
- Trait selection at fertilization (Incorrect. Traits are not selected at fertilization and if they should be, this would likely reduce genetic differences.)
- Crossing over within a homologous pair during meiosis (Correct. Crossing over generates unique combinations of alleles not seen in the parents and potentially not shared by siblings.)
A: Crossing over within a homologous pair during meiosis

Q: Which of the processes below would be a larger contributor to unique offspring?
- Mitosis (Incorrect. Mitosis yields genetically identical offspring, except for small differences due to mutations.)
- Translocations (Incorrect. Translocations would not be a larger contributor to unique offsprings than another option.)
- Random fertilizations (Correct. Random fertilizations will have the largest contribution to unique offspring from the choices available.)
A: Random fertilizations

Q: Which type of cells would all be unique from one another?
- body cells (Incorrect. Body cells will show some differences between cell types but within a single type should be quite similar.)
- none (Incorrect. There are types of cells in which individual cells will be unique from each other.)
- gametes (Correct. Gametes should be unique from each other when the effects of crossing over and random alignment of homologous chromosomes are taken into account.)
A: gametes

Q: A ________ is based on size, banding patterns, and centromere positions of chromosomes.
- genotype (Incorrect. The genotype is simply the genetic composition of an organism.)
- phenotype (Incorrect. The phenotype is the expression of traits in an organism.)
- karyotype (Correct. A karyotype provides information on all chromosomes arranged by size, banding patterns, and centromere positions.)
A: karyotype

Q: Human ________ are named based on approximate size order.
- karyotypes (Incorrect. A karyotype provides information on all chromosomes arranged by size, banding patterns, and centromere positions.)
- genotypes (Incorrect. A genotype is just the genetic composition of an organism. All human genotypes should be the same, or nearly the same, size.)
- chromosomes (Correct. The names of chromosomes are based roughly on size.)
A: chromosomes

Q: The simplest use of a ________ is to identify changes in chromosome number.
- phenotype (Incorrect. Phenotypes do not automatically identify changes in chromosome numbers.)
- genotype (Incorrect. Genotyping is an extensive process; there are much easier ways to identify changes in chromosome numbers.)
- karyotype (Correct. Because karyotypes provide information on all the chromosomes from a patient, it is very easy to detect changes in the total chromosome number.)
A: karyotype

Q: ________ are useful for identifying abnormal chromosomal numbers.
- Phenotypes (Incorrect. Phenotypes do not automatically identify changes in chromosome numbers.)
- Genotypes (Incorrect. The genotype is simply the genetic composition of an organism. While they could identify abnormal chromosomal numbers, they require a lot of expensive lab work and are better suited to examining individual genes, not all the chromosomes at once.)
- Karyograms (Correct. Karyograms are the actual images obtained from conducting a karyotype. Therefore they are useful for actually counting chromosomes.)
A: Karyograms

Q: A nondisjunction event in ________ causes all gametes to be mutant.
- meiosis II (Incorrect. A nondisjunction in meiosis II would only result in half the gametes having abnormal chromosome numbers.)
- mitosis (Incorrect. Mitosis does not generate gametes.)
- meiosis I (Correct. A nondisjunction in meiosis I would cause all resulting cells to have an abnormal chromosomal number.)
A: meiosis I

Q: A(n) ________ individual has a change in the correct number of an individual chromosome.
- euploid (Incorrect. An euploid individual has the correct number of each chromosome.)
- polyploid (Incorrect. A polyploid individual has an increase in the copy number of the entire genome (an increase in all the chromosome numbers).)
- aneuploid (Correct. An aneuploid individual has a change in the number of an individual chromosome.)
A: aneuploid

Q: A polyploid individual has ________.
- a change in the correct number of an individual chromosome (Incorrect. An aneuploid individual has a change in the number of an individual chromosome.)
- a change in the correct number of multiple chromosomes (Incorrect. This would be an aneuploid individual, though changes in the number of multiple chromosomes are rare.)
- a complete extra set of chromosomes (Correct. A polyploid individual has an increase in the copy number of the entire genome (an increase in all the chromosome numbers).)
A: a complete extra set of chromosomes

Q: Identify the syndrome below that results from an aneuploidy of an autosome.
- Turner syndrome (Incorrect. Turner syndrome is aneuploidy of the X chromosome.)
- Klinefelter syndrome (Incorrect. Klinefelter syndrome is aneuploidy of the X chromosome.)
- Down syndrome (Correct. Down syndrome is trisomy 21, 3 of the autosomal chromosome 21.)
A: Down syndrome

Q: Turner syndrome results from a(n) ________ of a sex chromosome.
- trisomy (Incorrect. Turner syndrome is not caused by a trisomy.)
- euploidy (Incorrect. Turner syndrome does not result from having the correct copy number of a sex chromosome.)
- monosomy (Correct. Turner syndrome results from having only 1 copy of the X chromosome.)
A: monosomy

Q: The trisomy of the ________ is less severe than many other trisomies due to ________.
- X chromosome; Y activation (Incorrect. There is no such things as Y activation.)
- Y chromosome; Y activation (Incorrect. There is no such things as Y activation.)
- X chromosome; X inactivation (Correct. Because X inactivation is used to leave only a single X chromosome active in an organism, it can function to turn off any extra X chromosomes beyond a single copy.)
A: X chromosome; X inactivation

Q: Duplications or deletions of only a part of a chromosome in humans often result in ________.
- no phenotypic change in an individual (Incorrect. It is very rare that a duplication or deletion of part of a chromosome will not have an impact.)
- spontaneous miscarriage of fetuses (Incorrect. An organism can usually survive some duplications or deletions of parts of chromosomes.)
- physical and mental abnormalities (Correct. An organism can usually survive some duplications or deletions of part of a chromosome but there will be an impact such as physical and/or mental abnormalities.)
A: physical and mental abnormalities