Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology > 3b. MITOSIS > Flashcards

3b. MITOSIS Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Describe what mitosis is

A

Mitosis is the production of identical daughter cells for growth and repair.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe the importance of mitosis

A

Mitosis is needed for growth, repair of damaged cells and replacement of worn out cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

State the number of daughter cells mitosis produces.

A

2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Why might some tissues have a faster rate of mitosis / shorter cell cycle?

A

Because cells are damaged / lost faster, e.g. in the small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

State how long it takes for a mammalian cell to complete a cell cycle

A

24 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Define what the cell cycle is

A

The cell cycle includes all the stages that take place that cause one cell to divide into two daughter cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Recall all the stages of the cell cycle

A

Interphase, Prophase, Metaphase, Anaphase, Telophase and Cytokinesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Name the stages of interphase, and what happens at each stage

A
  • G1 (cell growth & organelle replication)
  • S (DNA replication)
  • G2 (cell growth and organelle replication)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Define mitosis

A

The splitting of the nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which stages of the cell cycle are part of mitosis?

A

Prophase, metaphase, anaphase, telophase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Which stages of the cell cycle are not part of mitosis?

A

Interphase and cytokinesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What percentage of the whole cell cycle is interphase?

A

90%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Total length of the cell cycle = 25 hours.
Total cells in the cell cycle = 60.
Cells in anaphase = 10.
Calculate the length of anaphase.

A

10 / 50 = 0.2
25 x 0.2 = 5 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are sister chromatids?

A

Two identical copies of a chromosome produced during DNA replication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is a centromere?

A

Centromeres are the binding sites on the sister chromatids for the spindle fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are centrioles?

A

Centrioles are organelles where the spindle fibres develop from​

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are spindle fibres?

A

These connect the centrioles and centromeres, and pull the chromosomes to the poles of the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe what happens during interphase

A

The cell grows and organelles replicate.
DNA replication occurs.
G1 (cell growth), S (DNA replication) & G2 (cell growth)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Why are mutations more likely to occur during interphase?

A

DNA replication occurs in interphase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Why are the cells produced in mitosis called clones?

A

Because they are genetically identical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe what happens during prophase

A

Chromosomes condense and become visible. They are now two sister chromatids, joined at the centromere.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Describe what happens during metaphase

A

Chromatids attach to spindle fibres by their centromeres. Chromosomes line up on the equator of the cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Describe what happens during anaphase

A

The centromeres spilt and sister chromatids are pulled to the opposite poles of the cell. They are now referred to as chromosomes again. This stage requires ATP.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe what happens during telophase

A

Chromosomes uncoil. Two nuclear envelopes reform.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Describe what happens during cytokinesis.

A

The cytoplasm divides to form two daughter cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Recall the equation to calculate mitotic index

A

Mitotic index = number of cells with visible chromosomes / total number of cells observed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Recall the percentage the cell is in interphase

A

90%

28
Q

What is a tumour?

A

A mass of undifferentiated cells formed from uncontrolled cell division

29
Q

How is uncontrolled cell division caused?

A

Mutations

30
Q

Name the two types of tumours

A

Benign and Malignant

31
Q

Which type of tumour is classed as cancer?

A

Malignant

32
Q

Why are benign tumours not cancerous?

A

Because they do not mestastisise, so pieces that break off cannot start new tumours elsewhere in the body

33
Q

Why are malignant tumours cancerous?

A

Because they mestastasise. Therefore they can spread to other parts of the body and form new, secondary tumours.

34
Q

Describe three ways tumours can cause damage to the body

A

Damaging the organ concerned, causing blockages or obstructions, exerting pressure on other organs

35
Q

Why are mutagenic agents dangerous?

A

They increase the rate / chance of mutations occuring

36
Q

Name mutagenic agents

A

Radiation, X-Rays, UV rays, cigarette tar (any carcinogen)

37
Q

The chance of developing cancer is a combination of which two things?

A

Genes and exposure to mutagenic agents

38
Q

Why are people with a family history of cancer at a greater risk of developing cancer?

A

Because cancer has a genetic component which can be inherited. These genes give a predisposition to cancer

39
Q

Define what a risk factor is

A

A factor that increases the rate of a disease (in a population)

40
Q

Name a risk factor for lung cancer

A

Smoking

41
Q

Name a risk factor for liver cancer

A

Alcohol

42
Q

Name a risk factor for cervical cancer

A

HPV

43
Q

Name a risk factor for stomach / bowel cancer

A

High fat diet

44
Q

Name a risk factor for skin cancer

A

UV Rays

45
Q

Why are darker skinned people at a lower risk of developing skin cancer than lighter skinned people?

A

Darker skinned people have more melanin, which absorbs more UV Rays and prevents burning.

46
Q

State the two things cancer drugs inhibit

A

DNA polymerase and spindle fibre formation / function

47
Q

Describe how inhibiting DNA polymerase would treat cancer

A

It would prevent DNA replication by preventing the formation of phosphodiester bonds in the new DNA strand

48
Q

What would a cell look like once a drug that inhibits DNA Polymerase had taken effect?

A

The chromosomes would be visible but not fully condensed, so you wouldn’t see individual chromosomes.

49
Q

Describe how inhibiting spindle fibre formation would treat cancer

A

It would prevent sister chromatids from being pulled to the opposite poles of the cell

50
Q

What would a cell look like once a drug that inhibits spindle fibre formation had taken effect?

A

The chromosome would be fully condensed and visible as sister chromatids, but unable to line up on the equator

51
Q

What would a cell look like once a drug that inhibits spindle fibre function had taken effect?

A

The chromosomes would be lined up on the equator, but unable to be pulled to the poles of the cell

52
Q

Why might using drugs that inhibit DNA replication be problematic?

A

Because healthy cells also undergo mitosis

53
Q

Why would using drugs that inhibit DNA replication affect cancer cells more than healthy cells?

A

Because cancer cells undergo mitosis at a faster rate, therefore more cancer cells are killed.

54
Q

Why is mitosis important in single-celled organisms?

A

Single celled organisms reproduce by making genetically identical copies of themselves

55
Q

Name the process by which prokaryotic cells divide

A

Binary Fission

56
Q

Describe the process of binary fission

A

The circular DNA replicates, the cytoplasm divides to produce two identical daughter cells.

57
Q

Why can viruses only replicate inside a host cell?

A

They are non-living

58
Q

How do viruses attach to host cells before injecting their genetic material?

A

Using attachment proteins

59
Q

Once a virus has injected its genetic material into a host cell, how does the host cell produce the viral components?

A

Transcription and translation

60
Q

Once the viral components have been assembled inside the host cell, how do they exit the host cell?

A

By budding off

61
Q

Describe the process of budding off

A

When a new virus leaves a host cell, part of the host cell’s membrane forms an envelope around the virus and detaches, forming the new virus cell membrane

62
Q

When preparing to look at onion cells under the microscope to calculate mitotic index, why must only the very ends of the roots be used?

A

Because this is the meristem, where cells are undergoing mitosis

63
Q

What two processes do you carry out to ensure you end up with one layer of cells?

A

Separate the cells using a mounted needle, and squash the roots using the side of your fist

64
Q

Why is it important to end up with one layer of cells?

A

So light can pass through so you can view the chromosomes

65
Q

In which order do you use the focus knobs when focussing the image?

A

Coarse, then fine

66
Q

How do you calculate mitotic index?

A

Number of cells in mitosis / Total number of cells

Biology (26 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions