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Flashcards in Chapter 12 Deck (34)
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1
Q

What is the purpose of mitosis in multicellular orgnaisms?

A
  • Development from zygote

- Growth and repair

2
Q

Genome

A

All the DNA in a cell

3
Q

Why is DNA coiled into chromosomes?

A

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

4
Q

What does 1 chromosome consist of?

A

1 long coiled strand of DNA and protein

5
Q

Centromere

A

Narrow waist between replicated chromosome where chromatids are attached

6
Q

In which phase does the centriole replicate?

A

G2

7
Q

What is the centrosome?

A

Microtubule organizing center

8
Q

What forms from centrosomes?

A

Spindle microtubules and aster

9
Q

How do microtubules shorten during anaphase?

A

Depolymerizing at the kinetochore

10
Q

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

A

Overlap each other and elongate cell

11
Q

What is the process that seperates animal cells?

A

Cleavage

12
Q

What forms during cleavage?

A

Cleavage furrow

13
Q

How do plant cells perform cytokinesis?

A

Cell plate forms from vesicles from golgi apparatus

14
Q

How does a cleavage furrow split cell?

A

Actin microfilaments interact with myosin proteins to form ring and contract

15
Q

Explain the steps of binary fission

A

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

16
Q

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

A

Through checkpoints

17
Q

What is the cell cycle driven by?

A

Specific chemical signals present in cytoplasm

18
Q

What is the most important checkpoint?

A

G1 checkpoint

19
Q

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

A

It will enter G0, nondividing phase

20
Q

What are cyclin-dependent kinases?

A

Regulatory protein that needs to be activated by cyclin to work

21
Q

What is a cyclin?

A

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

22
Q

What is MPF?

A

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

23
Q

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

A

It is destroyed

24
Q

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

A

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

25
Q

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

A

Kinetochores send out internal signal to delay anaphase

26
Q

What are the three external signals?

A
  • Growth factors
  • Density-dependent inhibition
  • Anchorage dependence
27
Q

What are growth factors

A

Proteins released that stimulate other cells to divide

28
Q

What is density-dependent inhibition?

A

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

29
Q

What is anchorage dependence?

A

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

30
Q

How do cancer cells disregard growth factors?

A
  • Make own growth factor
  • Convey signal without presence of the receptor
  • Have abnormal cell cycle control system
31
Q

What is transformation?

A

Process that converts normal cell to cancerous cell

32
Q

What is a benign tumor?

A

When cancerous cells remain at original site

33
Q

What is a malignant tumor?

A

When cancerous cells invade surrounding tissues

34
Q

What is the process of metastasize?

A

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