Ch. Meiosis and Mitosis

A cell contains 40 chromatids at the beginning of mitosis. How many chromosomes will it contain at the completion of cytokinesis?

20

How many chromatids does a human somatic cell contain after interphase and just prior to mitosis?

92

The region of a chromosome holding the two double strands of replicated DNA together is called ________ a) an aster b) a chromatid c) chromatin d) a centromere e) a centriole

a centromere

Which event or events occur during anaphase? a) all of the above b) the centrioles are at opposite poles c) identical chromatids move to opposite poles d) the centromeres divide e) a spindle made of microtubules is present

all of the above

Which of the following structures is/are part of the mitotic spindle? a) kinetochore microtubules b) centrosome c) the aster d) nonkinetochore microtubules e) all of the above

all of the above

The function of the mitotic cell cycle is to produce daughter cells that __________. a) have a random assortment of maternal and paternal chromosomes b) have the same number of chromosomes as the parent cell but not the same genetic content c) are genetically identical to the parent cell (assuming no mutation has occurred) d) have the same number of chromatids as the parent cell had chromosomes

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

Which of the following statements correctly describes the difference(s) between mitosis and binary fission? a) binary fission involves the replication and division of a single chromosome, whereas mitosis involves the division of multiple, replicated chromosomes b) there are no differences between binary fission and mitosis c) a cell plate forms across the middle of two cells dividing by binary fission, but this does not occur in mitosis d) binary fission involves the replication and division of multiple chromosomes, whereas mitosis involves the replication and division of a single chromosome e) binary fission in bacteria is completed by microtubules, but mitosis does not involved these structures

binary fission involves the replication and division of a single chromosome, whereas mitosis involves the division of multiple, replicated chromosomes

What is the difference between a benign tumor and a malignant tumor? a) cells of benign tumors do not metastasize; those of malignant tumors do b) cells of benign tumors metastasize; those of malignant tumors do not c) benign tumors arise by transformation; malignant tumors do not d) benign tumors do not arise by transformation; malignant tumors do e) benign tumors will not kill you; malignant tumors will

cells of benign tumors do not metastasize; those of malignant tumors do

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

chromatin

In animal cell mitosis, the cleavage furrow forms during which stage of the cell cycle? a) metaphase b) the G1 phase c) prophase d) anaphase e) cytokinesis

cytokinesis

During interphase, the genetic material of a typical eukaryotic cell is ________ a) dispersed in the cytoplasm as long strands of chromatic b) condensed and the chromosomes are often visible under the light microscope c) dispersed in the nucleus as long strands of chromatin d) transported through the nuclear pores e) attached to microtubule spindle fibers

dispersed in the nucleus as long strands of chromatin

Cytokinesis refers to ________ a) movement of a cell from one place to another b) division of the cytoplasm c) reduction in the number of chromosomes d) division of the nucleus e) division of the entire cell

division of the cytoplasm

Observation of cancer cells in culture support the hypothesis that cancer cells ________ a) produce molecules that inhibit the growth factors required for cell division b) exhibit anchorage dependence c) do not exhibit density-dependent inhibition d) spend the majority of their time in the G0 phase

do not exhibit density-dependent inhibition

Chromatids are ________ a) held together by the centrioles b) the bacterial equivalent of eukaryotic chromosomes c) composed of RNA d) found only in aberrant chromosomes e) identical copies of each other if they are part of the same chromosome

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

You would know a dividing cell was a plant cell rather than an animal cell if you saw that __________. a) it formed cleavage furrow b) it formed a cell plate c) it had microtubules d) it had two pairs of centrioles during prophase e) the nucleolus was visible during metaphase

it formed a cell plate

The spread of cancer cells to other locations in the body is known as

metastasis

Checkpoints in the cell cycle control system __________ a) only stop cells from dividing b) have no effect on the cell cycle c) regulate the cell cycle through a variety of stop and go signals d) only signal cells to undergo mitosis e) ensure that a cell keeps dividing f) stop cancer cells from dividing

regulate the cell cycle through a variety of stop and go signals

Which of the following events does NOT occur during interphase of the cell cycle? a) production of new mitochondria b) production of the endoplasmic reticulum c) growth of the cell d) protein production e) separation of the sister chromatids

separation of the sister chromatids

Which of the following phases of mitosis is essentially the opposite of prometaphase in terms of the nuclear envelope? a) S phase b) telophase c) interphase d) metaphase e) anaphase

telophase

A cell biologist examined the DNA content of a cell from a fruit fly larva during the G1 phase and determined that it had 150 units of DNA. After measuring the DNA content of the same type of cell after the G2 phase, it was discovered that the cell had 300 units of DNA. How is this possible? a) the DNA was replicated during the S phase of interphase, which occurs between the two G phases b) the DNA was replicated after the G2 phase of interphase c) the DNA was replicated prior to interphase d) the DNA was replicated during the G2 phase of interphase e) the DNA was not replicated, this was the result of a mutation f) the DNA was replicated during the G1 phase of interphase

the DNA was replicated during the S phase of interphase, which occurs between the two G phases

DNA replication occurs in __________ a) the cytokinesis portion of the cell's life cycle b) prophase of both mitosis and meiosis c) metaphase of meiosis only d) the S phase of interphase in both somatic and reproductive cells e) the G1 phase of interphase in reproductive cells only

the S phase of interphase in both somatic and reproductive cells

One event occurring during prophase is __________ a) division of the centromere b) cytokinesis c) the alignment of chromosomes in a single plane d) the beginning of the formation of a spindle apparatus e) the synthesis of a new nuclear envelop

the beginning of the formation of a spindle apparatus

Which of the following statements describes a cell that undergoes mitosis but not cytokinesis? a) the cell has undergone transformation and become a cancer cell b) the cell does not contain a nucleus c) the cell dies d) the cell has not proceeded through interphase e) the cell has one nucleus f) the cell contains more than one nucleus

the cell contains more than one nucleus

Which of the following events occurs during metaphase of mitosis? a) the chromosomes condense b) the nuclear envelope forms again c) the sister chromatids are pulled apart toward the opposite sides of the cell d) the chromosomes align along the metaphase plate of the cell e) the nuclear envelope disappears f) the mitotic spindle forms

the chromosomes align along the metaphase plate of the cell

Which of the following events does not occur during prophase of mitosis? a) nucleoli disappear b) the mitotic spindle forms c) each duplicated chromosome appears as two identical sister chromatids d) the chromosomes condense e) the centrosomes move away from each other f) the mitotic spindle breaks down

the mitotic spindle breaks down

Which of the following events occurs during the prometaphase of mitosis? a) the mitotic spindle forms b) nuclear envelope forms again c) the sister chromatids are pulled toward opposite sides of the cell d) the chromosomes align along the metaphase plate of the cell e) the nuclear envelope fragments f) the centrosomes move away from each other

the nuclear envelope fragments

How does the process of mitosis differ between most eukaryotes and other eukaryotes such as diatoms and dinoflagellates? a) the nuclear envelope fragments in most eukaryotes but remains intact in diatoms and dinoflagellates b) the chromosomes are not duplicated prior to mitosis in diatoms and dinoflagellates c) the nuclear envelope remains intact in most eukaryotes but fragments in diatoms and dinoflagellates d) sister chromatids are not separated during mitosis in diatoms and dinoflagellates e) microtubules do not facilitate the movement of chromosomes in diatoms and dinoflagellates

the nuclear envelope fragments in most eukaryotes but remains intact in diatoms and dinoflagellates

During binary fission in a bacterium ________ a) the two DNA molecules break up into plasmids b) the origins of replication move apart c) the two DNA molecules attach to the centrioles d) the two DNA molecules float free in the cell and are guided to daughter cells by a spindle-like apparatus e) the two DNA molecules divide in half, forming four DNA fragments

the origins of replication move apart

Which of the following events occurs during anaphase of mitosis? a) spindle fibers attach to the centromeres of the chromosomes b) the mitotic spindle forms c) the nuclear envelope fragments d) the chromosomes align along the metaphase plate of the cell e) the sister chromatids are pulled apart toward opposite sides of the cell f) the nuclear envelope forms again

the sister chromatids are pulled apart toward opposite sides of the cell

Which of the following events occurs during telophase of mitosis? a) the chromosomes align on the metaphase plate b) the sister chromatids separate c) the nuclear envelope fragments d) two distinct daughter nuclei form in the cell e) DNA replicates f) the chromosomes condense

two distinct daughter nuclei form in the cell