Cell Division Flashcards
What is the difference between centrioles and centrosomes?
Centrioles are in centrosome
What is the microtubule organizing center?
Centrosome
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 __________.
centromere
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 __________.
No. Cells with 16 chromosomes would be produced by meiosis.
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
During interphase, the genetic material of a typical eukaryotic cell is __________.
dispersed in the nucleus as long strands of chromatin
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
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
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 question asks about number of centrioles.
The phase of mitosis during which the chromosomes move toward separate poles of the cell is __________.
anaphase
In animal cell mitosis, the cleavage furrow forms during which stage of the cell cycle?
cytokinesis
Which process does NOT occur in dividing bacteria?
mitosis. Bacteria has an inward growth of the plasma membrane
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 synthesis begins immediately in the original G1 nucleus. This is because the cell in S phase has moved past the G1 checkpoint.
Tissue culture experiments with PDGF demonstrate that without this substance __________.
fibroblasts fail to divide. PDGF is a growth factor.
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. Cells in the G0 phase have assumed a nondividing state.
If a human somatic cell is just about to divide, it has __________ chromatids.
92
At which phase of the cell cycle do centrioles begin to move apart in animal cells?
Prophase
In the cells of many eukaryotic species, the nuclear envelope has to disappear to permit which of the following events in the cell cycle?
attachment of microtubules to kinetochores
During which phase of mitosis do the chromatids become chromosomes?
Anaphase
Which of the following events occurs during interphase of the cell cycle?
replication of the DNA
G1 is associated with which of the following cellular events?
normal growth and cell function
In what way do kinetochore microtubules facilitate the process of splitting the centromeres?
They create tension by pulling toward opposite poles.
What is the name of the microtubule-organizing center found in animal cells as an identifiable structure present during all phases of the cell cycle?
centrosome
In a diploid cell with 5 chromosome pairs (2n = 10), how many centromeres will be found in a nucleus at G2 of the cell division cycle?
10
Besides the ability of some cancer cells to over proliferate, which of the following situations might logically result in a tumor?
lack of appropriate cell death
Starting with a fertilized egg (zygote), a series of six cell divisions would produce an early embryo with how many cells?
64
One difference between cancer cells and normal cells is that cancer cells.
continue to divide even when they are tightly packed together.
Which of the following does not occur during mitosis?
replication of the DNA
Movement of the chromosomes during anaphase would be most affected by a drug that prevents which of the following events in mitosis and cell division?
shortening of microtubules
Eukaryotic chromosomes are composed of which of the following macromolecules?
DNA and proteins
The mitotic spindle plays a critical role in which of the following processes?
separation of sister chromatids
Metaphase is characterized by ________.
alignment of chromosomes on the equator of the cell
cleavage furrow is ________.
a groove in the plasma membrane between daughter nuclei
If an intestinal cell in a butterfly contains 24 chromosomes, a butterfly egg would contain ____.
12
Which of the following represents chromosome # during fertilization?
2n=n+n
why is the chromosome number an even number in organisms?
The diploid chromosome number represents pairs of chromosomes, one from ech parent, so that it is always an even number
Mendel hypothesized that reproductive cells have only one factor for each inherited trait. This hypothesis is supported by the observation that_____.
haploid cells are produced by meiosis
What is one advantage of sexual reproduction?
offspring inherit a wider variety of genetic information
Mitosis is essential to life because it____
maintains genetic continuity from one generation to the next
How is the process used to produce sex cells different from the process used to produce body cells?
only the process used to make sex cells produces haploid cells
A male shark has 40 chromosomes in each of its sex cells. How many would be present in its body cells? 80
Based only on the sex chromosomes in typical human egg and sperm cells at fertilization, the probability of producing a female is____.
50%
Body cells of fruit flies contain 8 chromosomes. Scientists used studies of flies to discover how egg and sperm are formed. What did they observe?
Egg cells have 4 chromosomes
What is meiosis?
It occurs only in cells in the reproductive structures of an organism
The cells produced at the end of meiosis contain half the number of chromosomes as the parent cell. T or F?
T
Give a cell typenthat is formed by meiosis.
Sperm cell
Which process is necessary for the inherited traits of an organism to be passed along by sexual reproduction?
Meiosis
Which cell division produces identical nuclei in cells?
Mitosis
