BIO 190 DSM/Mastering Biology Ch. 9
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
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 each contained 200 units of DNA. What would be the amount of DNA at G1 of the cell cycle in a daughter cell of one of these cells
100 units
When not engaged in the processes leading to cell division, how many chromosomes from your mother are present in the nucleus of each of your somatic cells?
23
If a human somatic cell is in metaphase, it has __________ chromatids
92
Down syndrome is characterized by cells having three copies of chromosome 21. As a somatic cell in an individual with Down syndrome prepares to enter mitosis, how many chromatids would be present in the cell's nucleus?
94
During mitosis, microtubules attach to chromosomes at the ______.
Kinetochores
Which of the following processes does not occur in dividing bacteria?
Mitosis
During _____ both the contents of the nucleus and the cytoplasm are divided.
Mitotic phase Mitosis: Nucleus divides Cytokinesis: Cytoplasm divides
The ____ ______ is a cell structure consisting of microtubules, which forms during early mitosis and plays a role in cell division
Mitotic spindles
You would be unlikely to see which of the following human cells dividing?
Nerve cell
During binary fission of a bacterium, __________.
Origins of replication move apart
In a human skin cell that is going through the cell cycle, when do the centrosomes separate?
Prophase
DNA replication produces two identical DNA molecules, called ________, which separate during mitosis.
Sister Chromatids
During interphase, the genetic material of a typical eukaryotic cell is..
dispersed in the nucleus on long strands of chromatin
One event occurring during prophase is __________.
the beginning of the formation of a mitotic spindle
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
What is the difference between a benign tumor and a malignant tumor?
Cells of benign tumors do not metastasize; those of malignant tumors do
After chromosomes condense, the _______ is the region where the identical DNA molecules are most tightly attached to each other.
Centromeres
The _____ are the organizing centers for microtubules involved in separating chromosomes during mitosis
Centrosomes
During interphase, most of the nucleus is filled wit ha complex of DNA and protein in a dispersed form called _____.
Chromatin
In most eukaryotes, division of the nucleus is followed by _______, when the rest of the cell divides.
Cytokinesis
The cleavage furrow forms during which stage of mitosis and cell division of an animal cell?
Cytokinesis
During interphase, the genetic material of a typical eukaryotic cell is __________.
Dispersed in the nucleus as long strands of chromatin
Observations of cancer cells in culture support the hypothesis that cancer cells __________.
Do not exhibit density-dependent inhibition
Which of the following does not occur during mitosis?
Duplication of chromosomes
Tissue culture experiments with PDGF demonstrate that without this substance __________.
Fibroblasts fail to divide
In dividing cells, most of the cell's growth occurs during what phase?
Interphase
During _____ the cell grows and replicates both its organelles and its chromosomes
interphase
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