U2 Chapter 12: The Cell Cycle

Question 1

Cell Division

Answer 1

Included mitosis (division of the nucleus) and meiosis
- unicellular organisms need this to reproduce
- multicellular organisms need this for growth and repair OR development from a fertilized egg

Question 2

Genome

Answer 2

Genetic material (DNA) of a cell

Question 3

Chromosome

Answer 3

A threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes

Question 4

Chromatin

Answer 4

The complex of genomic DNA with proteins called histones, where each histone-bound DNA molecule is referred to as a chromosome
- gametes = one set of chromosomes
- somatic cells = two sets of chromosomes

Question 5

Sister Chromatids

Answer 5

The identical copies (chromatids) formed by the DNA replication of a chromosome, with both copies joined together by a common centromere
- cells replicate their DNA before dividing, so chromosomes are duplicated in this manner so each resulting cell are the same

Question 6

Cell Cycle

Answer 6

Ordered sequence of events in the life of a cell

Question 7

Interphase

Answer 7

In between divisions: G1, S, and G2 phase
- cell grows throughout interphase, DNA being replicated during synthesis (S) phase
- mitotic (M) phase include mitosis and cytokinesis

Question 8

Mitotic Spindle

Answer 8

Made up of microtubules, controls chromosome movement during mitosis
- in animal cells, it arises form the centrosomes and includes spindle microtubules and askers
- some spindle microtubules attach to the kinetochores or chromosomes and move the chromosomes to the metaphase plate

Question 9

Mitosis

Answer 9

A process where a single cell divides into two identical daughter cells
- usually followed by cytokinesis by cleavage and the plant cells form a cell plate

Question 10

Cell Cycle Control System

Answer 10

Regulates the process where cyclic changes in regulatory proteins (cyclins and cyclin dependent kinases (Cdks)) work as a cell cycle clock that has checkpoints at G1, G2, and M phases

Question 11

Density-dependent Inhibition

Answer 11

Occurs when cells grow to a limited density then growth becomes inhibited, possibly by cell-cell contacts
- tumor cells have often lost density-dependent inhibition

Question 12

Anchorage Dependence

Answer 12

An increase in proliferation which is seen when cells are allowed to attach to a solid surface

Question 13

Malignant Tumors

Answer 13

Formed by unchecked cell division where it can invade nearby tissue and undergo metastasis, exporting cancer cells to other sites, where they may form secondary tumors