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