Mitosis & Meiosis Assignment Questions

Front 1

Nucleoli are present during _____.

Back 1

Interphase

Front 2

Cytokinesis often, but not always, accompanies ___

Back 2

Telophase

Front 3

Chromosomes become visible during _____.

Back 3

Prophase

Front 4

Centromeres divide and sister chromatids become full-fledged chromosomes during _____.

Back 4

Anaphase

-> During anaphase, sister chromatids separate and daughter chromosomes migrate to opposite poles.

Front 5

Spindle fibers attach to kinetochores during _____.

Back 5

Prometaphase.

Front 6

Condensation of chromatin and the dispersal of nucleoli occurs when?

Back 6

Prophase

Front 7

The attachment of spindle fibers to kinetochores occurs when?

Back 7

Prometaphase

Front 8

During prophase a homologous pair of chromosomes consists of _____.

Back 8

Two chromosomes and four chromatids.

Front 9

During _____ both the contents of the nucleus and the cytoplasm are divided.

Back 9

The mitotic phase.

-> The mitotic phase encompasses both mitosis and cytokinesis. However MITOSIS does not include cytokinesis.

Front 10

During _____ the cell grows and replicates both its organelles and its chromosome

Back 10

Interphase

Front 11

Which of the following is true of kinetochores?

Back 11

They are sites at which microtubules attach to chromosomes.

-> As the spindle depolymerizes, the kinetochores appear to move along the spindle fiber, dragging the attached chromosomes with them.

Front 12

Which of the following correctly matches a phase of the cell cycle with its description?

Back 12

A) M: duplication of DNA
B) G1: follows cell division
C) S: immediately precedes cell division
D) G2: cell division
E) All of the above are correctly matched.
Correct

Hint 12

B.

-> After mitosis and cytokinesis, the newly formed daughter cells enter the G1 phase.

Front 13

In some organisms, such as certain fungi and algae, cells undergo the cell cycle repeatedly without subsequently undergoing cytokinesis. What would result from this?

Back 13

Large cells containing many nuclei

Front 14

At which phase are centrioles beginning to move apart in animal cells?

Back 14

Prophase

Front 15

What is a cleavage furrow?

Back 15

a groove in the plasma membrane between daughter nuclei

Front 16

Which of the following is a function of the S phase in the cell cycle?

Back 16

The synthesis of sister chromatids.

-> DNA replication occurs during S phase and results in two sister chromatids for each original chromosome.

Front 17

The copying of chromosomes occurs during which of the following phases of the cell cycle?

Back 17

S phase

-> Reminder: think "synthesis"
-> Chromosomes must undergo replication before mitosis can occur; this copying occurs during the S phase.

Front 18

For the first several divisions of early frog embryos, cells proceed directly from the M phase to the S phase and back to M without gaps. Which of the following is likely to be true about dividing cells in early frog embryos?

Back 18

The cells get smaller with each generation.

-> Without gap phases, the cells have no opportunity to grow.

Front 19

True or false? The M phase is characterized by the replication and division of a cell's chromosomes.

Back 19

False.

-> Cells replicate their chromosomes during the S phase and divide partition their chromosomes during the M phase.

Front 20

If an organism normally has 34 chromosomes, how many molecules of DNA should there be in the G1 phase of the cell cycle?

Back 20

34.

-> There is one DNA molecule per chromosome.

Front 21

Which of the following events would cause the cell cycle to arrest?

Back 21

a) Complete chromosome replication

b) Synthesis of cyclins by growth factors and activation of a cyclin-Cdk complex

c) Poor nutrient conditions

d) Chromosomes lined up along the metaphase plate

Hint 21

C) POOR NUTRIENT CONDITIONS.

Poor nutrient conditions would arrest the cell cycle at the G1 checkpoint.

Front 22

Cells will usually divide if they receive the proper signal at a checkpoint in which phase of the cell cycle?

Back 22

G1

-> In mammalian cells, this checkpoint is termed the restriction point.

Front 23

The decline of MPF activity at the end of mitosis is due to

Back 23

The degradation of cyclin.

Front 24

At which stage of mitosis are chromosomes usually photographed in the preparation of a karyotype?

Back 24

Metaphase.

-> This is when they're all lined up at the center of the cell (metaphase plate).

Front 25

Meiosis I produces _____ cells, each of which is _____.

Back 25

Meiosis I produces TWO cells, each of which is HAPLOID.

Front 26

Meiosis II typically produces _____ cells, each of which is _____.

Back 26

Meiosis II typically produces FOUR cells, each of which is HAPLOID.

Front 27

In meiosis, during _____ sister chromatids separate.

Back 27

Anaphase II

-> Anaphase II is essentially the same as mitotic anaphase except that the cell is haploid.

Front 28

At the end of _____ and cytokinesis, haploid cells contain chromosomes that each consist of two sister chromatids.

Back 28

Telophase I

Front 29

When do homologous chromosomes pair in meiosis?

Back 29

Homologous chromosomes pair during prophase I.

Front 30

Synapsis occurs during _____.

Back 30

Prophase I

Front 31

Homologous chromosomes migrate to opposite poles during _____.

Back 31

Anaphase I

-> During anaphase I sister chromatids remain attached at their centromeres, and homologous chromosomes move to opposite poles.

Front 32

During _____ chromosomes align single file along the equator of a haploid cell.

Back 32

Metaphase II

-> Metaphase II is essentially the same as mitotic metaphase except that the cell is haploid.

Front 33

At the end of _____ and cytokinesis there are four haploid cells.

Back 33

Telophase II

-> At the end of telophase II and cytokinesis there are four haploid cells

Front 34

Mitosis results in the formation of how many cells; meiosis results in the formation of how many cells?

Back 34

two diploid cells ... four haploid cells

-> In mitosis a cell that has doubled its genetic material divides to produce two diploid daughter cells. In meiosis a cell that has doubled its genetic material undergoes two rounds of division, producing four haploid cells.

Front 35

What is crossing over?

Back 35

The exchange of homologous portions of nonsister chromatids

-> The result is new combinations of genetic material (genetic recombination).

Front 36

Chromatids are separated from each other when?

Back 36

True for mitosis and meiosis II

Front 37

Which of the following occurs in meiosis but not in mitosis?

Back 37

Synapsis of chromosomes

Front 38

Which of the following happens at the conclusion of meiosis I?

Back 38

Homologous chromosomes are separated.

Front 39

Independent assortment of chromosomes is a result of

Back 39

the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I.

Front 40

Independent assortment of chromosomes occurs.

Back 40

In meiosis I

Front 41

One difference between cancer cells and normal cells is that cancer cells

Back 41

They continue to divide even when tightly packed together.

Front 42

Vinblastine is a standard chemotherapeutic drug used to treat cancer. Because it interferes with the assembly of micro-tubules, its effectiveness must be related to

Back 42

Disruption of mitotic spindle formation

Front 43

The drug cytochalasin B blocks the function of actin. Which of the following aspects of the animal cell cycle would be most disrupted by cytochalasin B?

Back 43

cleavage furrow formation and cytokinesis

Front 44

Define locus.

Back 44

A specific place along the length of a chromosome where a given gene is located.

Front 45

Meiosis I:

Back 45

The first division of a two-stage process of cell division in sexually reproducing organisms that results in cells with half the number of chromosomes sets as the original cell.

Front 46

Variation:

Back 46

differences between members of the same species.

Front 47

Somatic cell:

Back 47

Body cell.

Any cell in a multicellular organism except a sperm or egg or their precursors.

Front 48

Gene:

Back 48

A discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA (or RNA in some viruses).

Front 49

Alteration of generations:

Back 49

A life cycle in which there is both a multicellular diploid form (the sporophyte) and a multicellular haploid form (the gametophyte).

-> Characteristic of plants and some algae.

Front 50

Homologous chromosomes:

Back 50

A pair of chromosomes of the same length, centromere position, and staining pattern that possess genes for the same characters at corresponding loci.

ONE homologous chromosome is inherited from the organism's father and the other is inherited from the mother.

ALSO CALLED: homologs or homologous pair.

Front 51

Karyotype:

Back 51

A display of the chromosome pairs of a cell arranged by size and shape.

Front 52

Haploid cell:

Back 52

A cell containing only one set of chromosomes (n).

Front 53

Sex chromosome:

Back 53

A chromosome responsible for determining the sex of an individual.

Front 54

Autosome:

Back 54

A chromosome that is not directly involved in determining sex; not a sex chromosome.

Front 55

Recombinant chromosome

Back 55

A chromosome created when crossing over combines DNA from two parents into a single chromosome.

Front 56

Heredity:

Back 56

The transmission of traits from one generation to the next.

Front 57

Diploid cell:

Back 57

A cell containing two sets of chromosomes (2n), one set inherited from each parent.

Front 58

he person credited with first recognizing (in the 1860s) that living cells cannot arise spontaneously, but arise only from previously existing cells, is _____.

Back 58

Rudolf Virchow

Front 59

The function of the mitotic cell cycle is to produce daughter cells that _____.

Back 59

are genetically identical to the parent cell (assuming no mutation has occurred)

Front 60

The complex of DNA and protein that makes up a eukaryotic chromosome is properly called _____.

Back 60

chromatin

Front 61

The region of a chromosome holding the two double strands of replicated DNA together is called _____.

Back 61

centromere

Front 62

The centromere is a region in which _____.

Back 62

sister chromatids are attached to one another in prophase

Front 63

How many maternal chromosomes are present in a somatic human cell not engaged in cell division?

Back 63

23.

Front 64

"Cytokinesis" refers to _____.

Back 64

Division of the cytoplasm

Front 65

Chromatids are _____.

Back 65

identical copies of each other if they are part of the same chromosome

Front 66

If a cell contains 60 chromatids at the start of mitosis, how many chromosomes will be found in each daughter cell at the completion of the cell cycle?

Back 66

30

Front 67

A biochemist measured the amount of DNA in cells growing in the laboratory and found that the quantity of DNA in the cells doubled _____.

Back 67

between the G1 and G2 phases

-> Between these two phases of the cell cycle, the DNA is replicated during the S phase.

Front 68

A cell biologist carefully measured the quantity of DNA in grasshopper cells growing in cell culture. Cells examined during the G2 phase of the cell cycle contained 200 units of DNA. What would be the amount of DNA at G1 of the cell cycle in one of the grasshopper daughter cells?

Back 68

100 units.

-> Note: Cell division is very exact. The amount of DNA would never be indicated by a range.

Front 69

During interphase, the genetic material of a typical eukaryotic cell is _____.

Back 69

Dispersed in the nucleus as long strands of chromatin.

Front 70

DNA replication occurs in _____.

Back 70

the S phase of interphase in both somatic and reproductive cells

Front 71

f a somatic human cell is just about to divide, it has _____ chromatids.

Back 71

92

Front 72

Down syndrome is characterized by cells having three copies of chromosome 21. As a cell in an individual with Down syndrome prepares to enter mitosis, how many chromatids would be present?

Back 72

94.

Front 73

During what phase in the cell cycle would you find the most DNA per cell?

Back 73

G2 of interphase.

Front 74

In telophase of mitosis, the mitotic spindle breaks down and the chromatin uncoils. This is essentially the opposite of what happens in _____.

Back 74

Prophase.

During prophase, we observe the formation of the spindle, the condensation of chromatin, and the disappearance of the nucleolus.

Front 75

Which of the following phases of mitosis is essentially the opposite of prometaphase in terms of the nuclear envelope?

Back 75

Telophase.

-> In prometaphase the nuclear envelope fragments and the kinetochores attach to microtubules. During telophase, fragments of the nuclear envelope begin to reassemble along with portions of the endomembrane system.

Front 76

What is the difference between a benign tumor and a malignant tumor?

Back 76

Cells of benign tumors do not metastasize; those of malignant tumors do.

Front 77

Observations of cancer cells in culture support the hypothesis that cancer cells _____.

Back 77

do not exhibit density-dependent inhibition

Front 78

You would be unlikely to see what type of human cell dividing; one example:

Back 78

nerve cell.

Front 79

Tissue culture experiments with PDGF demonstrate that without this substance _____.

Back 79

Fibroblasts fail to divide.

Front 80

When a cell in S phase is fused with a cell in G1, _____.

Back 80

DNA synthesis begins immediately in the original G1 nucleus

-> This observation indicates that cytoplasmic signals can participate in the regulation of the cell cycle

Front 81

Which of the following is involved in the binary fission of bacteria?

Back 81

distribution of a copy of the single parental chromosome to each daughter cell

Front 82

During binary fission in a bacterium _____.

Back 82

the origins of replication move apart

->

Front 83

Does mitosis occur in bacteria?

Back 83

NO!!!

Front 84

You would know a dividing cell was a plant cell rather than an animal cell if you saw that _____.

Back 84

it had formed a cell plate.

-> The cell plate, which divides the cytoplasm in two, forms during the telophase of mitosis in a plant cell.

Front 85

At which stage of mitosis are chromosomes lined up in one plane in preparation for their separation to opposite poles of the cell?

Back 85

Metaphase

Front 86

During which stage of the cell cycle do sister chromatids separate?

Back 86

Anaphase

Front 87

Which event or events occur during anaphase?

Back 87

1) The centromeres divide
2) Identical chromatids move to opposite poles
3) A spindle made of microtubules is present
4) The centrioles are at opposite poles.

Front 88

Following cytokinesis in an animal cell, how many centrioles does each new daughter cell possess?

Back 88

TWO.

Front 89

In a human skin cell that is going through the cell cycle, when do the centrosomes separate?

Back 89

Prophase

Front 90

Assume that you are dealing with a species in which the number of chromosomes in each somatic cell is 14. How many sister chromatids are present in the early telophase of mitosis?

Back 90

ZERO.