Chapter 12 Pt 1

Question 1

Function of cell division

Answer 1

reproduction
Growth and development
Tissue renewal

Question 2

Genome

Answer 2

All of the genetic material in an organism

-DNA is organized into chromosomes

Question 3

Chromosomes

Answer 3

A cellular structure composed of a single long DNA molecule and associated proteins
-proteins are important for coiling and folding of DNA

Question 4

Chromatin

Answer 4

DNA+Proteins

Question 5

Chromosome organization in prokaryotes

Answer 5

DNA is found in the Nucleoid region

• not membrane-bound
• single circular chromosome
• less DNA
• may have plasmids

Question 6

Plasmids

Answer 6

• small, circular DNA molecule
• few genes
• replicate independently

Question 7

Cell division in prokaryotes

Answer 7

• replicate by binary fission

- before a cell can divide, it must grow larger and replicate its DNA

Question 8

Chromosome organization in eukaryotes

Answer 8

• DNA enclosed nucleus
• multiple linear chromosomes
• more DNA
• humands have 46 chromosomes in their somatic cells
• 23 chromosomes in human gametes (sperm and egg)

Question 9

Cell division in eukaryotes

Answer 9

Mitosis: nuclear division
-cells accurately and precisely segregate chromosomes to daughter cells

Cytokinesis: division of cytoplasm

Question 10

Cell division

Answer 10

The reproduction of cells

-produces two genetically identical daughter cells from one parent cell

Question 11

The cell cycle

Answer 11

Interphase:
G1: cell grows by producing more proteins, organelles, lipids, etc.
S phase: chromosomes are duplicated
G2: cell grows more and prepares to divide

M-phase:
Mitosis: division of nucleus
Cytokinesis: division of the cytoplasm

Question 12

Sister chromatids

Answer 12

Identical copies of each chromosome

-held together at centromere by cohesion proteins

Question 13

Sister chromatids separate during mitosis

Answer 13

During mitosis:

• cohesion proteins are degraded
• the sister chromatids segregate to become individual chromosomes
• pulled to opposite sides of the microtubules

Question 14

Before mitosis begins

Answer 14

• DNA and cent roomed have been duplicated

- nuclear envelope is intact

Question 15

Centrosomes

Answer 15

Microtubules organizing center

-each Centrosomes has a pair of centrioles

Question 16

Mitosis phases

PPMAT

Answer 16

Prophase
Prometaphase
Metaphase
Anaphase
Telophase

Question 17

Prophase

Answer 17

-chromosomes begin to condense
-mitosis spindle begins to form
•microtubules are assembled
•Centrosomes separate

Question 18

Prometaphase

Answer 18

• chromosomes are further condensed

- rad sister chromatid now has a kinetochore

Question 19

Kinetochore

Answer 19

• protein complexes associated with the centromeres
• nuclear membrane breaks down
• microtubules attach to kinetochores

Question 20

Metaphase

Answer 20

• Centrosomes are at opposite poles of the cell

- chromosomes align at the metaphase plate; imaginary plane that is equidistant between the two poles of the cell

Question 21

Anaphase

Answer 21

• cohesin proteins are cleaves

- sister chromatids segregated to opposite poles

Question 22

Telophase

Answer 22

• spindle microtubules are broken down
• two daughter nuclei form
• chromosomes become less condensed