Chapter 12 Flashcards Preview

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Flashcards in Chapter 12 Deck (34):
1

What is the purpose of mitosis in multicellular orgnaisms?

-Development from zygote
-Growth and repair

2

Genome

All the DNA in a cell

3

Why is DNA coiled into chromosomes?

To condense so that each cell receives that accurate amount of genetic information

4

What does 1 chromosome consist of?

1 long coiled strand of DNA and protein

5

Centromere

Narrow waist between replicated chromosome where chromatids are attached

6

In which phase does the centriole replicate?

G2

7

What is the centrosome?

Microtubule organizing center

8

What forms from centrosomes?

Spindle microtubules and aster

9

How do microtubules shorten during anaphase?

Depolymerizing at the kinetochore

10

What do the microtubules that don't connect to kinetochores do?

Overlap each other and elongate cell

11

What is the process that seperates animal cells?

Cleavage

12

What forms during cleavage?

Cleavage furrow

13

How do plant cells perform cytokinesis?

Cell plate forms from vesicles from golgi apparatus

14

How does a cleavage furrow split cell?

Actin microfilaments interact with myosin proteins to form ring and contract

15

Explain the steps of binary fission

Chromosomes replicates beginning at origin of replication and the two chromatin move to each side. Origins push to elongate and form new cells

16

If DNA is the same in every somatic cell, how do some cells divide quicker?

Through checkpoints

17

What is the cell cycle driven by?

Specific chemical signals present in cytoplasm

18

What is the most important checkpoint?

G1 checkpoint

19

What happens if cell at G1 checkpoint does not receive signal to go ahead?

It will enter G0, nondividing phase

20

What are cyclin-dependent kinases?

Regulatory protein that needs to be activated by cyclin to work

21

What is a cyclin?

Regulatory protein that activates Cdk to form complex that triggers cells passage past certain checkpoint

22

What is MPF?

Cyclin-dependent kinase and cyclin complex that triggers cell's passage past G2 checkpoint into M phase

23

What happens to the cyclin of MPF after the M phase is over?

It is destroyed

24

How does the cyclin and MPF concentration change during the cell cycle?

Cyclin gradually increases and increases at point between G2 and interphase; MPF only appears during that point

25

What happens if not all kinetochores are connected to a microtubule?

Kinetochores send out internal signal to delay anaphase

26

What are the three external signals?

-Growth factors
-Density-dependent inhibition
-Anchorage dependence

27

What are growth factors

Proteins released that stimulate other cells to divide

28

What is density-dependent inhibition?

If area is too crowded, surrounding cells use receptor proteins to signal cell to stop dividing

29

What is anchorage dependence?

Most animal cells need to be attached to a surface before division (another cell or in culture)

30

How do cancer cells disregard growth factors?

-Make own growth factor
-Convey signal without presence of the receptor
-Have abnormal cell cycle control system

31

What is transformation?

Process that converts normal cell to cancerous cell

32

What is a benign tumor?

When cancerous cells remain at original site

33

What is a malignant tumor?

When cancerous cells invade surrounding tissues

34

What is the process of metastasize?

When malignant tumors transport cancer cells to other parts of body and form secondary tumors