BIO Ch. 2 Reproduction

Question 1

What are the stages of interphase?

Answer 1

G0, G1, S,and G2

Question 2

What happens in G0?

Answer 2

sells are simply living and serving their function without any preparation for division

Question 3

What happens in G1?

Answer 3

cells create organelles or energy and protein productions while increasing their size. certain criteria must be met before the cell can proceed to the S stage

Question 4

What happens in S?

Answer 4

cells replicate their genetic material so that each daughter cell will have identical copies and form sister chromatids

Question 5

What happens in G2?

Answer 5

the cells check to ensure that there are enough organelles and cytoplasm to divide b/w 2 daughter cells and check to make sure DNA replication can proceed correctly

Question 6

What happens in M1?

Answer 6

Mitosis and cytokinesis

Question 7

What are the 4 phases of mitosis?

Answer 7

prophase - chromosomes condense, and spindle fibers form
metaphase -chromosomes align
anaphase - sister chromatids separate
telophase - new nuclear membrane forms

Question 8

What is the purpose of the G1/S phase?

Answer 8

the cell determines if the DNA is in good enough condition for synthesis. if not, the cell goes into effect until it is repaired via P53

Question 9

What is the purpose of the G2/M phase?

Answer 9

The cell is mainly concerned with ensuring that the cell has achieved adequate size and that organelles have been properly replicated to support 2 daughter cells via P53.

Question 10

What is the role of cyclins and cyclic-dependent kinases (CDK)

Answer 10

cyclins bind to the CDKs, activating the CDK-cyclin complex. this complex can then phosphorylate transcription factions which promote the transcription of genes required for the next stage of the cell cycle

Question 11

What happens when TP53 is mutated?

Answer 11

the cell cycle is not stopped to repair damaged DNA, and as a result, mutation accumulates. Cancer cells can undergo rapid cell division, creating tumors

Question 12

What is mitosis?

Answer 12

the process by which 2 identical daughter cells are created from a single cell. this occurs in somatic cells

Question 13

What happens in prophase?

Answer 13

1. the chromatin condenses into chromosomes
2. centriole pairs separate and move towards opposite poles of the cell
3. the centrioles begin to form spindle fibers which are made up of microtubules
4. the nuclear membrane dissolves, allowing the spindle fibers to contact the chromosomes
5. the nucleoli disappears
6. kinetochores appear at the centromere serving as an attachment point for kinetochore fibers on the spindle apparatus

Question 14

What happens in Metaphase?

Answer 14

the centriole pairs are now at the opposite ends of the cell, and the kinetochore fibers interact with the spindle apparatus to align the chromosomes at the metaphase/equatorial plate

Question 15

What happens in Anaphase?

Answer 15

the centromeres split so that each chromatid has its centrosomes, allowing the sister chromatids to separate, and the kinetochore fibers shorten

Question 16

What happens in Telophase?

Answer 16

1. the spindle apparatus disappears
2. the nuclear membrane reforms around each set of chromosomes, and the nucleoli reappear
3. the chromosomes uncoil, resuming their interphase form
4. each nucleus has received a complete copy of the genome identical to the original genome and each other

Question 17

What happens in cytokinesis?

Answer 17

the cytoplasm and the organelles separate so that each daughter cell has sufficient supplies to survive on its own