Chapter 12 quiz

The defining characteristic of a malignant tumor is that _____.

its cells can spread to other parts of the body and produce secondary tumors

In which mitotic phase are the sister chromatids separated and pulled to opposite poles?

anaphase

What is the difference between a chromatid and a chromosome?

A chromatid is one half of a replicated chromosome, whereas a chromosome consists of DNA wrapped around proteins in a highly organized manner.

Which answer correctly associates a phase of mitosis with what happens to chromosomes during that phase?

Anaphase: Sister chromatids separate.

What two types of defects does a cancerous cell possess?

Cancerous cells possess defects that make proteins required for cell growth active and tumor suppressor genes inactive.

Which statement is correct concerning the relationship between chromosomes and either genes, chromatin, or sister chromatids?

Each replicated chromosome consists of two sister chromatids.

Two important checkpoints that regulate the cell's progression through the cell cycle occur in the _____ and _____ phases of the cell cycle.

G1, G2

Which answer correctly identifies a cell-cycle checkpoint with a criterion for passing it?

G2 checkpoint: Chromosomes have replicated successfully.

What two types of movement are responsible for separating sister chromatids during anaphase?

Kinetochore microtubules that depolymerize at the kinetochore proteins and polar microtubules that overlap and lengthen the cell.

Part complete Which group of cells would be least likely to contain cells in S phase?

No longer dividing cells of the mammalian brain

During what phase of the cell cycle does the DNA become replicated?

S

What major events occur during anaphase of mitosis?

The sister chromatids of replicated chromosomes separate, and the spindle poles are pushed farther apart.

MPF, or mitosis-promoting factor, consists of two important cell-cycle regulatory proteins called _____.

cyclin and cyclin-dependent kinase (CDK)

The division of the cytoplasm following mitosis is called _____.

cytokinesis

In which mitotic phase do the chromosomes condense and does the mitotic spindle begin to form?

prophase