Brainscape's Knowledge GenomeTM

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


See full index

WJEC AS Biology > Mitosis & Meiosis (Genetic information)-Unit 1.6 > Flashcards

Mitosis & Meiosis (Genetic information)-Unit 1.6 Flashcards

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

What type of cells does mitosis produce? (3)

A

Two identical daughter cells
Diploid
For growth and repair of tissues

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

At which stage of mitosis do chromosomes line up along the centre of the cell?

A

Metaphase.

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

During what stage of mitosis are chromatids pulled to opposite poles of the cell?

A

Anaphase.

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

What is the first stage of mitosis?

A

Prophase.

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

What is the second stage of mitosis?

A

Metaphase.

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

Name the third stage of mitosis.

A

Anaphase.

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

What is the final stage of mitosis?

A

Telophase.

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

What happens to the nuclear membrane during the telophase of mitosis?

A

It reforms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

During what phase are the chromatids finally considered chromosomes again during mitosis?

A

Telophase.

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

What do the chromosomes do during the telophase of mitosis?

A

Uncoil and lengthen.

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

What happens to the spindle and nucleolus during the telophase of mitosis?

A

Spindle breaks down and nucleolus reappears.

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

What are chromsomes made up of?

A

One long molecule of DNA which is wound in histone proteins to make DNA coil tightly for support.

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

Why is mitosis needed?

A

For growth of multicellular organisms and repairing damaged tissue.

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

Give some examples of what happens during the interphase of mitosis.

A
  • Replication of DNA
  • Making new organelles
  • Synthesis of ATP and ribosomal material
  • Increase in cell size (not growth)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

List the cell cycle: (3)

A

1.Interphase
2.Mitosis
•Prophase
•Metaphase
•Anaphase
•Telophase
3.Cytokinesis

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

What is a centromere?

A

The specialised region in which chromatids are joined.

17
Q

What are homologous pairs?

A

Matching pairs

18
Q

What is the difference between diploid and haploid cells?

A

Diploid- total number of chromosomes (body cell)

Haploid- half number of chromosomes (gametes)

19
Q

What happens during the interphase? (5)

A
  • Replication of DNA
  • Replication of organelles that have their own DNA (mitochondria & chloroplasts)
  • Making new organelles that DO NOT have own DNA
  • Synthesis of ribosomal material, ATP & proteins
  • Increase in cell size
20
Q

What happens during prophase in mitosis? (5)

A
  1. DNA condenses forming chromosomes
  2. Chromatids become visible
  3. Centrioles move to opposite poles
  4. Protein microtubules form and spindle developed from pole to pole
  5. Nuclear membrane disintegrates and nucleolus disappears.
21
Q

What happens during the metaphase in mitosis? (2)

A
  1. Chromosomes arrange at equator of spindle and become attached to spindle fibres at centromere.
  2. Contraction of spindle fibres draw individual chromatids apart.
22
Q

Describe the anaphase in mitosis. (4)

A
  1. Is very rapid
  2. Centromere spilts
  3. Spindle fibres contract
  4. Chromatids separate and pulled to opposite poles
23
Q

Describe the telophase in mitosis. (4)

A
  1. Chromatids have reached piles and are referred to as chromosomes again.
  2. They uncoil and lengthen.
  3. Spindle breaks down.
  4. Nucleolus reappears and nuclear membrane reforms.
24
Q

What does cytokinesis mean?

A

Cytoplasm splitting

25
Q

Mitosis lacks genetic variation. What is an advantage and disadvantage of this?

A

Ability to increase numbers quickly to take advantage of an ideal environment.

Lack leads to inability to adapt if environment changes.

26
Q

How does cancer form?

A

Result of uncontrolled mitosis.
Cancerous cells divide repeatedly with no control, with the formation of a tumour.
Thought to stem from mutations occurred in genes that control mitosis.

27
Q

What cells does meiosis produce?

A

4 genetically different daughter cells that are haploid.

28
Q

What happens in prophase 1

A

Paternal & maternal chromosomes associate as homologous pairs.
(each pair called bivalent)

29
Q

Metaphase 1:

A

Maternal & paternal chromosomes (bivalents) arrange randomly in equator- source of genetic variation.

30
Q

Anaphase 1:

A

Homologous pairs are separated.
Centromere DOES NOT SPLIT.
Chromosomes remain intact at this stage.

31
Q

Telophase 1:

A

The first meiotic division.
Chromosomes remain in condensed form.
Cytokinesis occurs after, followed by meiosis 2. (animal cells)

32
Q

Prophase 2:

A

New spindle develops at right angles to old ones

33
Q

Metaphase 2:

A

Chromosomes line up separately on spindle fibres.

Each chromosome is attached to spindle by centromere.

34
Q

Anaphase 2:

A

Spindle fibres contract.
Centromere spilts.
Chromatids pulled to opposite poles.

35
Q

Telophase 2:

A

Chromatids lengthen and spindle disappears.

Cytokinesis takes place.

WJEC AS Biology (9 decks)

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