Exam 3 Flashcards
At what point of the cell cycle would you see a chromosome look like this? (sister chromatids, centromeres on each chromatid)
Metaphase (M)
The chromosome begins M phase looking as shown. When does it split?
Anaphase (A)
What best describes the kinetochore?
Structure composed of several proteins that associate with the centromere region of a chromosome and that can bind to spindle microtubules
From prophase through metaphase of mitosis, each chromosome has ___ DNA molecules, while from anaphase through telophase of mitosis, each chromosome has ___ DNA molecule
Two; one
If you were given a slide and told that the cells on it were performing cytokinesis, how would you tell if you had plant cells or animal cells?
Look for a cell plate or cleavage furrow
Which comes immediately after S phase in the cell cycle?
G2
If a cell that had two copies of each chromosome, but problems with the spindle caused the sister chromatids to remain attached to each other and to only one spindle pole, what cells would result?
Cells with 4 copies of each chromosome and 0 copies of each chromosome
You are observing a line of rat cells and see that they repeatedly make mistakes in the cell cycle by going through the G2 checkpoint too early. This could be due to a ___.
Problem with the expression of a cyclin
The decline of MPF activity at the end of mitosis is due to
The degradation of cyclin
If a cell does not receive a go-ahead signal at G1 checkpoint during cell cycle, name the phase it enters as a nondividing state.
G0
Binary fission is more like animal cell division because
Bacteria and animals both pinch in to separate cytoplasm into two pieces
Privet shrubs and humans each have diploid number of 46 chromosomes per cell. Why are the two species so dissimilar?
The two species have appreciably different genes
Why is it more practical to prepare karyotypes by viewing somatic diploid cells rather than haploid gametes?
Both sets of chromosomes, which are present in somatic diploid cells, need to be examined.
Why does sexual reproduction (meiosis) have an advantage over asexual reproduction (mitosis)?
Meiosis increases genetic variation among offspring
The mosquito Aedes aegypti has a karyotype of 2n=6. Through independent assortment alone, how many chromosomal combinations can be made during meiosis?
8
A human cell containing 22 autosomes and a Y chromosome is
a sperm
If the DNA content of a diploid cell in the G1 phase of the cell cycle is x, then the DNA content of the same cell at metaphase of meiosis I will be
2x
Which of the following is not a reason that peas were well suited for Mendel’s breeding experiments?
Peas have an unusually long generation time