23
How many chomosomes pairs does a human have?
red blood cells
Which cell could you not use to produce a karyotype?
largest to smallest, with the sex chromosomes at the end
In a karyotype the chromosomes are arranged in order from
a particular gene contained a mutation
From a karyotype you could tell all of the following about the cell expect whether
T
T or F : In a karyotype, each chromosome contains two sister chromatids.
centromere
Two sister chromatids are held together at the
four
A homologous pair of chromosome contain how many chromatids?
8-12 weeks of pregnancy
When is chorionic villi sampling generally performed?
There is no danger to the fetus in removing chorionic villi.
Which of the following is not a reason chorionic villi sampling is used to determine the fetal karyotype?
no
Yes or No: Jessica and Nathan just found out they are pregnant. The doctor estimates it has been 6 weeks since her last menstruation. Can they have an amniocentesis done now?
interphase and cell division
What are the two parts of the cell cycle?
cytokinesis
Which of the following is not a stage of interphase?
In G1, the cell prepares to synthesize its DNA and in G2 it synthesizes the proteins needed for cell division.
How are G1 and G2 different?
F
T or F: The amount of time the cell takes for interphase is approximately 1 hour, plus or minus about 5 minutes.
during S of interphase
When does a chromosome go from one chromatid to two sister chromatids?
mitosis
Which comes first: mitosis or cytokinesis?
Both involve division
How are mitosis and cytokinesis alike?
The cell checks that the DNA has replicated
What happens at the G2 checkpoint?
G1 and G2
At what 2 checkpoints does the cell check for the integrity of the DNA?
T
T or F: External signals such as hormones and growth factors can stimulate a cell to go through the cell cycle.
stimulate it
How do proto-oncogenes affect the cell cycle?
mitosis
During development from a zygote to a child, what cell division process occurs?
F
T or F: When a child is born, mitosis ceases to function.
T
T of F: Following mitosis, the daughter cells are identical to the parent cell.
8
If a cell has 4 pair of chromosomes, after mitosis each daughter cell will have how many chromosomes?
aster
Which of the following is part of the mitotic spindle?
interphase
Which of the following is not a stage of mitosis?
prophase
At which stage of mitosis do you first see the chromosomes appearing?
anaphase
At what stage of mitosis do sister chromatids become chromosomes?
anaphase
At which stage of mitosis do the chromsomes look like the letter "V"?
prophase and telophase
In which two phases of mitosis does the nuclear membrane appear/disappear?
actin filaments
Which aspect of the cytoskeleton is involved in the cleavage furrow?
T
T or F: There is no mechanism to ensure the exact partitioning of the cytoplasm as there is of the DNA.
2, 4
In meiosis there are how many divisions and how many daughter cells?
T
T or F: If an organism does not undergo meiosis, then it cannot undergo sexual reproduction.
4
If an organism has 4 pairs of chromosomes, after meiosis it will contain how many chromosomes?
prophase I
In what stage of meiosis does synapsis occur?
anaphase I
In which stage of meiosis do homologous chromosomes separate from each other?
anaphase II
When do the centromeres divide in meiosis?
T
T or F: Sexual reproduction introduces more genetic variation than does asexual reproduction.
2
If there are 4 pairs of chromosomes, how many different combinations of chromosomes are possible?
metaphase I
Independent alignment creates genetic variation. This is associated with which stage of meiosis?
T
T or F: Genetic variation is useful to evolution because environments change.
meiosis
If you are looking at a cell in which 2n = 16, and there appear to be 8 structures lined up at the metaphase plate, then you are looking at
mitosis
If the parent cell has 24 chromosomes, and each of the daughter cells has 24 chromosomes, then the cell has undergone
meiosis II
Which division of meiosis is like mitosis?
Both result in cells with half the chromosome number
In what way is spermatogenesis similar to oogenesis?
F
T or F: In both spermatogenesis and oogenesis, one sperm/egg forms from one primary spermatocyte/oocyte.
It varies, but on the order of years.
How long does it take to proceed from prophase I to metaphase I in oogenesis?
T
T or F: If the secondary oocyte is not fertilized, it does not complete meiosis II.
F
T or F: All the products of oogenesis are the same size.
secondary spermatocytes
The product(s) of meiosis I in spermatogenesis is/are
4
If nondisjunction occurs during meiosis I, how many of the final 4 products will be abnormal?
2,1
Suppose that nondisjunction occurs during meiosis II in oogenesis, and each of the resulting 4 cells is fertilized with a normal sperm. How many cells are normal and how many have a chromosomal trisomy?
indeterminate genitalia
Which of the following is not a symptom of Down syndrome?
elevated levels of purines in the blood
Which of the following is associated with mental retardation in Down syndrome?
Turner syndrome
Which of the following syndromes has a karyotype with a missing X chromosome?
Both have three sex chromosomes
How are Jacobs and Klinefelter syndromes alike?
T
T or F: In a translocation, all of the DNA is present, and there is only one copy of each piece.
deletion
Which type of change in chromosome structure characterizes cri du chat syndrome?