Chapter 12 Practice Test

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

Rudolf Virchow

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

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

Which of the following is FALSE regarding sister chromatids?

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 __________.

chromatin

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

a centromere

The centromere is a region in which __________.

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?

23

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

There would be 32 chromosomes present in each of the daughter cells But not pairs

"Cytokinesis" refers to __________.

the division of the cytoplasm

Chromatids are __________.

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?

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 __________.

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?

100 units

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

dispersed in the nucleus as long strands of chromatin

DNA replication occurs in __________.

the S phase of interphase

If a human somatic cell is just about to divide, it has __________ chromatids.

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?

94

Which of the following does NOT occur during mitosis?

replication of chromosomes

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

G₂

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

prophase

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

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?

0

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

prophase

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

two

The phase of mitosis during which the chromosomes move toward separate poles of the cell is __________.

anaphase

One event occurring during prophase is __________.

the beginning of the formation of a spindle apparatus

Which event or events occur during anaphase?

begins when the cohesins connecting sister chromatids are cleaved, liberating the chromatids (now called chromosomes), which begin moving toward opposite poles of the cell.

Which of the following represents a mismatch or incorrect description?

metaphase: the nuclear envelope disappears

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

anaphase

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

cytokinesis

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

metaphase

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

it had formed a cell plate

Which of the following processes does NOT occur in dividing bacteria?

mitosis

During binary fission in a bacterium, __________.

the origins of replication move apart

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

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, __________.

DNA synthesis begins immediately in the original G₁ nucleus

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

fibroblasts fail to divide

You would be UNLIKELY to see which of the following human cells dividing?

nerve cell

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

The cancer cells do not exhibit density-dependent inhibition.

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

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