Mastering Biology Chapter 12
Which of these is NOT a carcinogen? UV light fat testosterone cigarette smoke
all of the above are carcinogens
Centromeres divide and sister chromatids become full-fledged chromosomes during _____.
anaphase
Spindle fibers attach to kinetochores during _____.
prometapase
Chromosomes become visible during _____.
prophase
Cytokinesis often, but not always, accompanies _____.
telophase
Starting with a fertilized egg (zygote), a series of five cell divisions would produce an early embryo with how many cells?
32
Density-dependent inhibition is explained by which of the following?
As cells become more numerous, the cell surface proteins of one cell contact the adjoining cells and they stop dividing.
The beginning of anaphase is indicated by which of the following?
Cohesin is cleaved enzymatically.
Cells will usually divide if they receive the proper signal at a checkpoint in which phase of the cell cycle?
G1
The cyclin component of MPF is destroyed toward the end of which phase?
M
Which of the following is released by platelets in the vicinity of an injury?
PDGF
Which of the following is true of benign tumors, but not malignant tumors?
They remain confined to their original site
Which of the following is a protein synthesized at specific times during the cell cycle that associates with a kinase to form a catalytically active complex?
cyclin
_____ is a carcinogen that promotes colon cancer.
fat
During _____ the cell grows and replicates both its organelles and its chromosomes.
interphase
Nucleoli are present during _____.
interphase
During _____ both the contents of the nucleus and the cytoplasm are divided.
the mitotic phase
During prophase a homologous pair of chromosomes consists of _____.
two chromosomes and four chromatids Submit