BIO 120 Ch 12 HW
The M phase checkpoint ensures that all chromosomes are attached to the mitotic spindle. If this does not happen, cells would most likely be arrested in ________.
metaphase
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?
20
In a diploid cell with 5 chromosome pairs (2n = 10), how many chromatids will be found in a nucleus at prophase of mitosis?
20
Starting with a fertilized egg (zygote), a series of six cell divisions would produce an early embryo with how many cells?
64
A human bone marrow cell, in prophase of mitosis, contains 46 chromosomes. How many chromatids does it contain? See Concept 12.1 (Page 236)
92
Which of the following properties is associated with a cyclin-dependent kinase (Cdk)?
A Cdk is an enzyme that attaches phosphate groups to other proteins
Cells will usually divide if they receive the proper signal at a checkpoint in which phase of the cell cycle? See Concept 12.3 (Page 244)
G1
The cell cycle control systems of cancer cells differ from those of normal cells. Select the best explanation for this fact.
Genetic changes alter the function of the cancer cell's protein products
Nucleoli are present during _____.
Interphase
Which of the following molecules is released by platelets in the vicinity of an injury?
PDGF
What is true of all cancers?
They have escaped normal cell cycle controls.
Cytokinesis in animal cells is accomplished by constriction of the cell along the plane of cell division (formation of a cleavage furrow). In plant cells, which have cell walls, a completely different mechanism of cytokinesis has evolved. Which of the following statements are true of cytokinesis in plant cells? Select the two that apply.
Vesicles from the Golgi apparatus move along microtubules, coalesce at the plane of cell division, and form a cell plate. The cell plate consists of the plasma membrane and cell wall that will eventually separate the two daughter cells.
Why is it difficult to observe individual chromosomes with a light microscope during interphase? See Concept 12.1 (Page 235)
Why is it difficult to observe individual chromosomes with a light microscope during interphase? See Concept 12.1 (Page 235) They have uncoiled to form long, thin strands.
Centromeres divide and sister chromatids become full-fledged chromosomes during _____.
anaphase
During which phase of mitosis do the chromatids become chromosomes?
anaphase
In the cells of some organisms, mitosis occurs without cytokinesis. This will result in
cells with more than one nucleus.
What two components constitute an active MPF?
cyclin and a cyclin-dependent kinase
At what stage of the cell cycle is the cyclin component of MPF destroyed?
in late M
Scientists isolate cells in various phases of the cell cycle. They isolate a group of cells that have 1 1/2 times more DNA than G1 phase cells. What is the most likely part of the cell cycle from which these cells were isolated?
in the S phase of the cell cycle
During _____ the cell grows and replicates both its organelles and its chromosomes.
interphase
Spindle fibers attach to kinetochores during _____.
prometaphase
Chromosomes become visible during _____.
prophase
Cytokinesis often, but not always, accompanies _____.
telophase
During _____ both the contents of the nucleus and the cytoplasm are divided.
the mitotic phase
