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Biology 111A Exam 2 > Mitosis > Flashcards

Flashcards in Mitosis Deck (69):
1

Cell Theory

All cells come from other cells
The basic unit of life is a cell

2

What are the two main phases of the cell cycle?

Growth and division

3

Both phases of the cell life cycle are extremely ___?

Controlled

4

When does cell division occur?

Growth
Development
Healing/regeneration
Asexual reproduction

5

In what organisms does cell division occur?

All organisms

6

When a cell is not dividing, what form is DNA in?

Chromatin

7

What is chromatin?

Thin threads of DNA and proteins

8

What are chromosomes?

Tightly coiled packages of DNA.

9

DNA is in chromosome form during what only?

Cell division

10

How many chromosomes do humans have?

46 (23 pairs)

11

Why is DNA in chromosome form during cell division?

Good for moving DNA around during replication

12

What is a sister chromatid?

Half of one chromosome

13

What is a centromere?

Pinched joining site of a chromosome

14

Cells spend most of their life in what phase?

Interphase

15

What are the stages of interphase?

G1, S, and G2

16

The amount of time a cell spends in interphase depends on what?

Cell type

17

When a cell is in interphase, what is happening?

The cell is living, undergoing normal function

18

A red blood cell would spend more or less time in interphase?
An osteocyte would spend more or less time in interphase?

Less
More

19

What occurs in G1 of interphase?

Cell doubles organelles

20

If a cell doesn't pass the G1 checkpoint, where does it go?

G0 or Gnot

21

What occurs in the S stage of interphase?

DNA replicates

22

What occurs in the G2 stage of interphase?

Makes proteins needed for division

23

What role do proteins play in cell division?

Check DNA copy for mistakes

24

The mitotic (M) phase of the cell cycle includes what?

Divison of nucleus and division of the cytoplasm

25

What is mitosis?

Division of the nucleus

26

What is cytokinesis?

Division of the cytoplasm

27

Once a cell goes through G1, what happens?

It commits to the cell cycle/replication

28

At the end of G2, what is a cell ready to do?

Divide

29

At the end of the M phase, what is the cell ready to do?

split

30

Internal control of the cell cycle is regulated by what?

proteins

31

What are some examples of proteins that internally regulate the cell cycle?

Kinases (Cdk)
Cyclins (cycle)
Cyclins + Cdks = MPF (maturation promoting factor)

32

What does increased MPF trigger?

G2 checkpoint passage

33

What are some examples of external control factors of the cell cycle?

Growth factors
Density-dependent inhibition
Anchorage dependence

34

What are regulated growth factors?

proteins that trigger cells to divide

35

What is density-dependent inhibition?

peripheral proteins tell the cell when to stop dividing due to high density

36

What is anchorage dependence?

cells must have something to divide on, so they grow on the substratum

37

What makes something a hormone?
What do they trigger?

A chemical that is effective in small amounts
Produced in one part of the body but doesn't have any effect there

Cell division

38

What is the goal of mitosis?

To produce two identical cells with identical DNA

39

What is the spindle made of?

Deconstructed cytoskeleton

40

What does the spindle do?

Move chromosomes around
Pull sister chromatids apart

41

What is the spindle-organizing center?
How many of them are there?

centrosome
2

42

What is an aster?

A description of the firework arrangement of spindles

43

What are centrioles?
Are they present in every organism?

Rods in centrosomes
No

44

What does a cell look like in interphase?

DNA in chromatin form
DNA already duplicated
Nucleus still circular and intact

45

What does a cell look like in prophase?

Chromatin condenses into chromosomes
Two sister chromatids are attached at a centromere
Nucleus disintegrates
Spindle forms

46

What is a kinetochore?
What are kinetochore and non-kinetochore spindles?

Protein on chromosome
Kinetochore- attaches to chromosomes
Non-kinetochore- doesn't attach to chromosomes

47

How does a spindle disassemble?

Motor protein chews on microtubule and spits out spindle fragments

48

What does a cell look like in metaphase?

Chromosomes line up at spindle equator
Spindle fibers either attach to chromosomes (tug-of-war), or they extend past the equator and overlap

49

What do non-kinetochore spindle fibers do?

Overlap and work to lengthen the cell and pinch in half

50

What does a cell look like in anaphase?

Spindle fibers pull sister chromatids apart to opposite sides
Unattached spindle fibers lengthen the cell

51

Sister chromatids are only called sister chromatids when they are ___? Once they separate, what are they?

Attached
chromosomes

52

What does a cell look like in telophase?

Chromosomes de-condense to chromatin
Two nuclei re-form
Spindle dis-assembles
Cytokinesis starts

53

Cytokinesis in an animal cell consists of what?
Cytokinesis in a plant cell consists of what?

Cleavage furrow
Cell plate

54

What is cancer?

A disease of the cell cycle
Genetically messed up but not all heritable

55

Cancer is classified by what?

Location

56

What is carcinoma?

skin cancer

57

What is sarcoma?

muscle tissue cancer

58

What is leukemia?

blood cancer

59

What are the five cancer characteristics?

Lack differentiation
Immortal (no cell apoptosis)
Abnormal nuclei (large, lobed) or chromosomes
Form tumors (no dependent inhibition)
Metastesize (spread)

60

What is carcinogenesis?

Cancer causing

61

What is a mutation?

A genetic change

62

What is angiogenesis?

A tumor causes the body to grow blood vessels to the tumor to supply it

63

What is benign?

Doesn't spread

64

What is malignant?

Harmful and might spread

65

What are the four types of cancer treatment?

Surgery
Chemo
Radiation
Hormone therapy

66

What do chemotherapy and radiation affect?

Actively dividing cells, causes physical fallout

67

What does hormone therapy do?

Interferes with cell communication

68

What are some cancer prevention behaviors?

Avoid smoking (30% of all cancer deaths)
Avoid sun exposure
Heavy drinkers more prone to particular cancers

69

What are some dietary measures that can be done to prevent cancer?

Weight loss reduces risk
Increase vitamin's A and C
Avoid salt-cured food
Include cabbage family members in diet