Biology Chapter 12- Study

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

1) Anton van Leeuwenhoek
2) Rudolf Virchow
3) Watson
4) Robert Hooke
5) Louis Pasteur

2) Rudolf Virchow
The function of the mitotic cell cycle is to produce daughter cells that __________.

1) are genetically identical to the parent cell (assuming no mutation has occurred)
2) have the same number of chromosomes as the parent cell but not the same genetic content
3) have the same number of chromatids as the parent cell had chromosomes
4) have a random assortment of maternal and paternal chromosomes
5) have none of the listed characteristics

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1) are genetically identical to the parent cell (assuming no mutation has occurred)
Which of the following is FALSE regarding sister chromatids?

1) Sister chromatids form in the S-phase stage of the cell cycle.
2) Sister chromatids are separated during mitosis.
3) Both of the sister chromatids end up in the same daughter cell after cytokinesis has occurred.
4) Sister chromatids are attached to one another at the centromere.
5) Sister chromatids are created when DNA is replicated.

3) Both of the sister chromatids end up in the same daughter cell after cytokinesis has occurred.
The complex of DNA and protein that makes up a eukaryotic chromosome is properly called __________.

1) a centromere
2) a chromoplast
3) chromatin
4) a chromatid
5) a centrosome

3) chromatin
The region of a chromosome in which the two double strands of replicated DNA are held together is called __________.

1) chromatin
2) a chromatid
3) a centriole
4) an aster
5) a centromere

5) a centromere
The centromere is a region in which __________.

1) sister chromatids are attached to one another in prophase
2) the chromosomes are connected to the cell plate in metaphase
3) microtubules are fastened to the centrioles during anaphase
4) chromosomes become aligned during metaphase
5) the new cell plate forms in telophase

1) sister chromatids are attached to one another in prophase
How many maternal chromosomes are present in a somatic human cell not engaged in cell division?

1) 23
2) 46
3) 92
4) 184
5) None of the listed responses is correct.

1) 23
A cell entering the cell cycle with 32 chromosomes will produce two daughter cells, each with __________.

1) 16 chromosomes
2) 64 chromosomes
3) 32 pairs of chromosomes
4) 64 pairs of chromosomes
5) none of the listed numbers of chromosomes

5) none of the listed numbers of chromosomes
“Cytokinesis” refers to __________.

1) the division of the nucleus
2) the division of the cytoplasm
3) the movement of a cell from one place to another
4) the division of the entire cell
5) the reduction in the number of chromosomes

2) the division of the cytoplasm
Chromatids are __________.

1) composed of RNA
2) found only in aberrant chromosomes
3) held together by the centrioles
4) the bacterial equivalent of eukaryotic chromosomes
5) identical copies of each other if they are part of the same duplicated chromosome

5) identical copies of each other if they are part of the same duplicated chromosome
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?

1) 15
2) 30
3) 45
4) 60
5) 120

2) 30
A biochemist measured the amount of DNA in cells growing in the laboratory and found that the quantity of DNA in the cells doubled __________.

1) between anaphase and telophase
2) between the G1 and G2 phases
3) between the G2 phase and prophase
4) between prophase and anaphase
5) during the M phase of the cell cycle

2) between the G1 and G2 phases
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?

1) 50 units
2) 100 units
3) between 50 and 100 units
4) 200 units
5) 400 units

2) 100 units
During interphase, the genetic material of a typical eukaryotic cell is __________.

1) dispersed in the nucleus as long strands of chromatin
2) condensed and the chromosomes are often visible under the light microscope
3) dispersed in the cytoplasm as long strands of chromatin
4) attached to microtubule spindle fibers
5) transported through the nuclear pores

1) dispersed in the nucleus as long strands of chromatin
DNA replication occurs in __________.
1) metaphase of mitosis
2) prophase of mitosis
3) the G1 phase of interphase
4) cytokinesis
5) the S phase of interphase
5) the S phase of interphase
If a human somatic cell is just about to divide, it has __________ chromatids.

1) 0
2) 23
3) 46
4) 92
5) There is insufficient information to answer the question.

4) 92
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? (eText Concept 12.2)

1) 23
2) 46
3) 92
4) 94
5) 98

4) 94
Which of the following does NOT occur during mitosis?

1) replication of chromosomes
2) condensation of chromatin
3) the movement of chromosomes to opposite poles
4) separation of chromatids
5) alignment of chromosomes along the cell’s equator

1) replication of chromosomes
During what phase in the cell cycle would you find the most DNA per cell?

1) S1
2) G0
3) S
4) G2
5) G1

4) G2
In telophase of mitosis, the mitotic spindle breaks down and the chromatin uncoils. This is essentially the opposite of what happens in __________.

1) anaphase
2) metaphase
3) prophase
4) S phase
5) interphase

3) prophase
Which of the following phases of mitosis is essentially the OPPOSITE of prometaphase in terms of the nuclear envelope?

1) S phase
2) anaphase
3) metaphase
4) telophase
5) interphase

4) telophase
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?

1) 0
2) 7
3) 14
4) 28
5) None of the listed responses is correct.

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

1) anaphase
2) metaphase
3) prophase
4) S phase
5) G2 phase

3) prophase
Following cytokinesis in an animal cell, how many centrioles does each new daughter cell possess?
1) zero
2) one
3) two
4) four
5) eight
3) two
The phase of mitosis during which the chromosomes move toward separate poles of the cell is __________.

1) prometaphase
2) anaphase
3) telophase
4) metaphase
5) prophase

2) anaphase
One event occurring during prophase is __________.

1) the division of the centromere
2) the beginning of the formation of a spindle apparatus
3) the alignment of chromosomes in a single plane
4) the synthesis of a new nuclear envelope
5) cytokinesis

2) the beginning of the formation of a spindle apparatus
Which event or events occur during anaphase?

1) A spindle made of microtubules is present during anaphase.
2) The centrioles are at opposite poles during anaphase.
3) Genetically identical chromosomes (previously sister chromatids) move to opposite poles during anaphase.
4) Cohesins joining sister chromatids at the centromeres are cleaved during anaphase.
5) All of the listed responses are correct.

5) All of the listed responses are correct.
Which of the following represents a mismatch or incorrect description?

1) anaphase: there is movement of the chromosomes to the poles
2) telophase: chromosomes become more extended
3) metaphase: the nuclear envelope disappears
4) metaphase: chromosomes line up on the equatorial plane
5) prophase: chromosomes become more tightly coiled

3) metaphase: the nuclear envelope disappears
During which stage of the cell cycle do sister chromatids separate?

1) prophase
2) G2 phase
3) anaphase
4) G1 phase
5) metaphase

3) anaphase
In animal cell mitosis, the cleavage furrow forms during which stage of the cell cycle?

1) the G1 phase
2) anaphase
3) cytokinesis
4) metaphase
5) prophase

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

1) metaphase
2) prophase
3) anaphase
4) telophase
5) interphase

1) metaphase
You would know that a dividing cell was a plant cell rather than an animal cell if you saw that __________.

1) the nucleolus was visible during metaphase
2) it had microtubules
3) it had two pairs of centrioles during prophase
4) it had formed a cell plate
5) it had formed a cleavage furrow

4) it had formed a cell plate
Which of the following processes does NOT occur in dividing bacteria?

1) replication of DNA
2) mitosis
3) separation of the origins of replication
4) binary fission
5) inward growth of the plasma membrane

2) mitosis
During binary fission in a bacterium, __________.

1) the two DNA molecules divide in half, forming four DNA fragments
2) the origins of replication move apart
3) the two DNA molecules attach to the centrioles
4) the two DNA molecules break up into plasmids
5) the two DNA molecules float free in the cell and are guided to daughter cells by a spindle-like apparatus

2) the origins of replication move apart
Which of the following is involved in the binary fission of most bacteria?
1) formation of a cell plate
2) formation of a spindle apparatus
3) disintegration of the nuclear membrane
4) prophase, prometaphase, metaphase, anaphase, and telophase
5) distribution of a copy of the single parental chromosome to each daughter cell
5) distribution of a copy of the single parental chromosome to each daughter cell
When a cell in S phase is fused with a cell in G1, __________.

1) the replication of DNA occurring in the original S nucleus is terminated
2) the original G1 cell will divide immediately
3) the chromosomes of the original G1 nucleus condense in preparation for mitosis
4) the two nuclei fuse and additional division is arrested
5) DNA synthesis begins immediately in the original G1 nucleus

5) DNA synthesis begins immediately in the original G1 nucleus
Tissue culture experiments with PDGF demonstrate that without this substance __________.

1) fibroblasts fail to divide
2) the various kinases, such as MPF, are unable to bind to cyclin
3) cells divide in an uncontrolled fashion, confirming PDGF’s role as a cell division inhibitor
4) bacterial cells lose their resistance to antibiotics
5) animal cells are unable to attach to the substratum

1) fibroblasts fail to divide
You would be UNLIKELY to see which of the following human cells dividing?

1) skin cell
2) nerve cell
3) cancer cell
4) cell from an embryo
5) All of these cell types are equally unlikely to divide at any given time.

2) nerve cell
Which of the following hypotheses is best supported by observing cancer cells in a culture?

1) The cancer cells do not exhibit density-dependent inhibition.
2) The cancer cells produce molecules that inhibit the growth factors required for cell division.
3) The cancer cells exhibit anchorage dependence.
4) The cancer cells spend the majority of their time in the G0 phase.
5) All of the listed responses are correct.

1) The cancer cells do not exhibit density-dependent inhibition.
What is the difference between a benign tumor and a malignant tumor?
1) Benign tumors do not arise by transformation; malignant tumors do.
2) Cells of benign tumors do not metastasize; those of malignant tumors do.
3) Benign tumors arise by transformation; malignant tumors do not.
4) Benign tumors will not kill you; malignant tumors will.
5) Cells of benign tumors metastasize; those of malignant tumors do not.
2) Cells of benign tumors do not metastasize; those of malignant tumors do.