Topic 1.6: Cell Division Flashcards Preview

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Flashcards in Topic 1.6: Cell Division Deck (68):
1

Define cell cycle

an ordered set of events which culminates in the division of a cell into two daughter cells

2

What is an ordered set of events which culminates in the division of a cell into two daughter cells?

cell cycle

3

Define interphase

The stage in the development of a cell between two successive divisions

4

What is The stage in the development of a cell between two successive divisions?

interphase

5

What are the 3 stages of interphase?

G1, S, G2

6

What happens during G1 of interphase?

First intermediate gap stage in which the cell grows and prepares for DNA replication

7

What happens during S of interphase?

Synthesis stage in which DNA is replicated

8

What happens during G2 of interphase?

Second intermediate gap stage in which the cell finishes growing and prepares for cell division

9

What stage of interphase is the First intermediate gap stage in which the cell grows and prepares for DNA replication?

G1

10

What stage of interphase is the Synthesis stage in which DNA is replicated?

S

11

What stage of interphase is the Second intermediate gap stage in which the cell finishes growing and prepares for cell division
?

G2

12

Define M phase

The period of the cell cycle in which the cell and contents divide to create two genetically identical daughter cells

13

What is The period of the cell cycle in which the cell and contents divide to create two genetically identical daughter cells?

M phase

14

What are the two stages of M phase?

mitosis and cytokinesis

15

What happens during mitosis?

Nuclear division, whereby DNA (as condensed chromosomes) is separated into two identical nuclei

16

What happens during cytokinesis of M phase?

Cytoplasmic division, whereby cellular contents are segregated and the cell splits into two

17

What stage of M phase does Nuclear division, whereby DNA (as condensed chromosomes) is separated into two identical nuclei?

mitosis

18

What stage of M phase does Cytoplasmic division, whereby cellular contents are segregated and the cell splits into two?

cytokinesis

19

What happens during interphase of mitosis? (4)

DNA is present as uncondensed chromatin (not visible under microscope)
DNA is contained within a clearly defined nucleus
Centrosomes and other organelles have been duplicated
Cell is enlarged in preparation for division

20

What happens during prophase of mitosis? (4)

DNA supercoils and chromosomes condense (becoming visible under microscope)
Chromosomes are comprised of genetically identical sister chromatids (joined at a centromere)
Paired centrosomes move to the opposite poles of the cell and form microtubule spindle fibres
The nuclear membrane breaks down and the nucleus dissolves

21

What happens during metaphase of mitosis? (3)

Microtubule spindle fibres from both centrosomes connect to the centromere of each chromosome
Microtubule depolymerisation causes spindle fibres to shorten in length and contract
This causes chromosomes to align along the centre of the cell (equatorial plane or metaphase plate)

22

What happens during anaphase of mitosis? (3)

Continued contraction of the spindle fibres causes genetically identical sister chromatids to separate
Once the chromatids separate, they are each considered an individual chromosome in their own right
The genetically identical chromosomes move to the opposite poles of the cell

23

What happens during telophase of mitosis? (4)

Once the two chromosome sets arrive at the poles, spindle fibres dissolve
Chromosomes decondense (no longer visible under light microscope)
Nuclear membranes reform around each chromosome set
Cytokinesis occurs concurrently, splitting the cell into two

24

During what stage of mitosis is DNA is present as uncondensed chromatin (not visible under microscope)?

interphase

25

During what stage of mitosis is DNA is contained within a clearly defined nucleus?

interphase

26

During what stage of mitosis is Centrosomes and other organelles have been duplicated?

interphase

27

During what stage of mitosis is Cell is enlarged in preparation for division?

interphase

28

During what stage of mitosis is DNA supercoils and chromosomes condense (becoming visible under microscope)?

prophase

29

During what stage of mitosis is Chromosomes are comprised of genetically identical sister chromatids (joined at a centromere)?

prophase

30

During what stage of mitosis is Paired centrosomes move to the opposite poles of the cell and form microtubule spindle fibres?

prophase

31

During what stage of mitosis is The nuclear membrane breaks down and the nucleus dissolves?

prophase

32

During what stage of mitosis is Microtubule spindle fibres from both centrosomes connect to the centromere of each chromosome?

metaphase

33

During what stage of mitosis is Microtubule depolymerisation causes spindle fibres to shorten in length and contract?

metaphase

34

During what stage of mitosis is This causes chromosomes to align along the centre of the cell (equatorial plane or metaphase plate)?

metaphase

35

During what stage of mitosis is Continued contraction of the spindle fibres causes genetically identical sister chromatids to separate?

anaphase

36

During what stage of mitosis is Once the chromatids separate, they are each considered an individual chromosome in their own right?

anaphase

37

During what stage of mitosis is The genetically identical chromosomes move to the opposite poles of the cell?

anaphase

38

During what stage of mitosis is Once the two chromosome sets arrive at the poles, spindle fibres dissolve?

telophase

39

During what stage of mitosis is Chromosomes decondense (no longer visible under light microscope)?

telophase

40

During what stage of mitosis is Nuclear membranes reform around each chromosome set?

telophase

41

What is the first step to cytokinesis in animal cells?

After anaphase, microtubule filaments form a concentric ring around the centre of the cell

42

After the After anaphase, microtubule filaments form a concentric ring around the centre of the cell what is the next step to cytokinesis in animal cells?

The microfilaments constrict to form a cleavage furrow, which deepens from the periphery towards the centre

43

After The microfilaments constrict to form a cleavage furrow, which deepens from the periphery towards the centre what is the next step to cytokinesis in animal cells?

When the furrow meets in the centre, the cell becomes completely pinched off and two cells are formed

44

After When the furrow meets in the centre, the cell becomes completely pinched off and two cells are formed what is the last step to cytokinesis in animal cells?

Because this separation occurs from the outside and moves towards the centre, it is described as centripetal

45

What is the first step to cytokinesis in plant cells?

After anaphase, carbohydrate-rich vesicles form in a row at the centre of the cell (equatorial plane)

46

After the After anaphase, carbohydrate-rich vesicles form in a row at the centre of the cell (equatorial plane) what is the next step to cytokinesis in plant cells?

The vesicles fuse together and an early cell plate begins to form within the middle of the cell

47

After The vesicles fuse together and an early cell plate begins to form within the middle of the cell what is the next step to cytokinesis in plant cells?

The cell plate extends outwards and fuses with the cell wall, dividing th cell into two distinct daughter cells

48

After The cell plate extends outwards and fuses with the cell wall, dividing th cell into two distinct daughter cells what is the last step to cytokinesis in plant cells?

Because this separation originates in the centre and moves laterally, it is described as centrifugal

49

What are cyclins?

a family of regulatory proteins that control the progression of the cell cycle

50

What are a family of regulatory proteins that control the progression of the cell cycle?

cyclins

51

How do cyclins work?

Cyclins activate cyclin dependent kinases (CDKs), which control cell cycle processes through phosphorylation

52

Define tumors

are abnormal cell growths resulting from uncontrolled cell division and can occur in any tissue or organ

53

Define cancers

Diseases caused by the growth of tumours

54

What are abnormal cell growths resulting from uncontrolled cell division and can occur in any tissue or organ?

tumors

55

What are Diseases caused by the growth of tumours called?

cancers

56

Define mutagen

an agent that changes the genetic material of an organism (either acts on the DNA or the replicative machinery)

57

What is an agent that changes the genetic material of an organism (either acts on the DNA or the replicative machinery)?

mutagen

58

Define carcinogens

Mutagens that lead to the formation of cancer

59

What are Mutagens that lead to the formation of cancer called?

carcinogens

60

Define oncogene

a gene that has the potential to cause cancer

61

What is a gene that has the potential to cause cancer?

oncogene

62

What are the two classes of genes that mutations happen to that cause cancers?

proto-oncogenes and tumour suppressor genes

63

What do proto-oncogenes code for?

code for proteins that stimulate the cell cycle and promote cell growth and proliferation

64

What do tumor suppressor genes code for?

code for proteins that repress cell cycle progression and promote apoptosis

65

What types of genes code for proteins that stimulate the cell cycle and promote cell growth and proliferation?

proto-oncogenes

66

What types of genes code for proteins that repress cell cycle progression and promote apoptosis?

tumor suppressor genes

67

Define metastasis

the spread of cancer from one location (primary tumour) to another, forming a secondary tumour

68

What is the spread of cancer from one location (primary tumour) to another, forming a secondary tumour?

metastasis

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