Chapter 12

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 telophse of mitosis?

0

a cell biologist carefully measured the quantity of DNA in grasshopper cells growing in the cell culture. Cells examined during the G2 phase of the cell ycle 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

if an intenstinal cell in a grasshopper contains 24 chromosomes, a grasshopper sperm cell would contain __ chromosomes.

12

How many maternal chromosomes are present in a somatic human cell in G1?

23

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

30

a cell entering the cell cycle with 32 chromosomes will produce two daughter cells, each with __.

32 chromosomes

if a somatic human cell is just about to divide, it has __ chromatids?

92

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

Rudolph Virchow

a biochemist measured the amount of DNA in cells growing in the lab and found that the quantity of DNA in the cells doubled __.

between the G1 and G2 phases

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

dispersed in the nucleus as long strands of chromatin

binary fission in bacterial cells involves __.

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

"cytokinesis" refers to __.

division of the cytoplasm

observations of cancer cells in culture support the hypothesis that cancer cells __.

do not exhibit density-dependent inhibition

chromatids form __.

during the S phase

tissue culture experiments with PDGF demonstrate that w/o this substance __.

fibroblasts fail to divide

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

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

in animal cell mitosis, the cleavage furrow forms during __.

cytokinesis

what does NOT occur during or because of mitosis?

replication of chromosomes

The centromere is the region in which __.

sister chromatids are attached to one another in prophase

what phase of mitosis is essentially the opposite of prometaphase in terms of the nuclear envelope?

telophase

DNA replication occurs in __.

the S phase of interphase in both somatic and reproductive cells

one event occuring during prophase is __.

the beginning of the formation of a spindle apparatus

chromatin

the co,plex of DNA and protein that makes up a eukaryotic chromosome

during binary fission in a bacterium __.

the origins of replication move apart

when a cell in S phase is fused with a cell in G1, __.

DNA sythesis immediately in the original G1 nucleus

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

G2

the region of a chromosomeholding the two double strands of replicated DNA together

a centromere

sister chromatids separate during __.

anaphase

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

anaphase

the function of the cell cycle is to produce daughter cells that __

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

TRUE OR FALSE: genes are transmitted during sexual reproduction, but not during asexual reproduction

false. in asexual reproduction, a singlr individual is the sole parent and passes copies of all its genes to its offspring

TRUE OR FALSE: metaphase: the nuclear envelope disappears

false. nuclear envelope fragments in prometaphase

chromatids are __.

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 __.

it had formed a cell plate

at which stage are chromosomes lined up in one plane in prep for their separation to opposite poles of the cell?

metaphase

what process does not occur in dividing bacteria?

mitosis

you would be unlikely to see which human cell dividing?

nerve cell

at which point in the cell cycle do centrosomes begin to move apart to two poles of the cell in a diviing human skin cell?

prophase

in the telophase of mitosis, the mitotic spindle breaks down and the chromatin uncoils. this is essentially the opposite of what happens in __.

prophase