3.2.2 - Mitosis and Cell Cycle Flashcards Preview

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Flashcards in 3.2.2 - Mitosis and Cell Cycle Deck (33):
1

What are the 4 stages of mitosis?

Prophase

Metaphase

Anaphase

Telophase (cytokinesis)

2

What does the diagram show?

Q image thumb

Anaphase

A image thumb
3

Cancer is caused by uncontrolled mitosis. How do most cancer drugs work?

1. Preventing DNA replication/

2. Inhibiting metaphase stage of mitosis by interfering with spindle formation.

4

What happens during prophase?

  • DNA condenses into chromosomes (becomes visible)
  • Centrioles move to opposite poles of cell and spindle fibres are released to form a spindle apparatus.
  • The nucleolus and nuclear envelope break down.

5

What does the diagram show?

Q image thumb

Telophase (leading to cytokinesis)

A image thumb
6

Describe the process of bacterial binary fission

  • Circular DNA and plasmids replicate.
  • The cell membrane begins to grow and pinches in around the two circular DNA molecules.
  • A new cell wall forms between the two circular DNA molecules dividing the cell into 2 idenitcal daughter cells.
  • The cells have variable numbers of plasmids.

7

What does the diagram show?

Q image thumb

Metaphase

A image thumb
8

When would mitosis not result in 2 identical daughter cells?

If there was a mutation (very rare)

9

Gametes (eggs and sperm) are haploid cells. What is meant by this?

They contain only 1 set of unparied chromosomes.

10

What is mitosis important for?

  • Growth
  • Repair of damaged cells.
  • Reproduction (single celled organisms)

11

Describe what happens when a virus replicates.

  • Attachment to host cell using attachment proteins on their surface.
  • Injection of nucleic acid into host cell.
  • Nucleic acid provides instructions for host cell's metabolic machinary to start producing new viral components e.g. enzymes and structural proteins.
  • Viral components packaged into new viruses.

12

What happens during metaphase?

Chromosomes are positioned along equator of cell by spindle fibres.

13

What is the product of mitosis?

2 daughter cells that have the same number of chromosomes as the parent cell and each other.

14

What does the diagram show?

Q image thumb

Prophase

A image thumb
15

The regular cycle of division separated by periods of cell growth is called...

the cell cycle

16

How much of a single cell cycle is spent in interphase?

approximately 90%

17

Bacterial cells replicate in a similar way to mitosis. What do we call their method of replication?

Binary Fission

18

The rate of mitosis is controlled by...

1. The environment of the cell

2. 'Growth factors'.

3. Two genes.

19

What happens during telophase?

  • Chromatids reach opposite poles.
  • Nucleas envelope and nucleolus reforms around chromosomes.
  • Spindle apparatus disintegrates.
  • Cytoplasm divides to complete cell division (cytokinesis).

20

What are the 3 stages of the cell cycle?

Interphase

Nuclear division

Division of cyctoplasm (cytokinesis)

21

How can we remember the order of the stages of mitosis?

  • Prophase - (Preparation - condensing and spindle formation)
  • Metaphase - (Middle - chromosomes lined up along middle of cell)
  • Anaphase - (Action - chromatids pulled apart)
  • Telophase - (Two - two new cells after division)

22

How long does a mammalian cell to undergo 1 complete cell cycle?

24 hours

23

What happens during anaphase?

  • Spindle fibres contract to pull sister chromatids apart at the centromere.
  • Chromatids move towards opposite poles.

24

When a chromosome (DNA) replicates, the new stand is initially joined to the old at a place called the...

centromere.

25

What are the advantages of reproducing via mitosis?

Only 1 parent required.

Beneficial qualities are more likely to be passed on to offspring.

26

A zygote is a diploid cell. What is meant by this?

A cell containing 2 complete sets of chromosomes (one from each parent)

27

What are the disadvantages of reproducing by mitosis?

Less variation in offspring.

Reduced ability to adapt to changing environment.

28

What does the diagram show?

Q image thumb

Interphase

A image thumb
29

Describe a cell that is in interphase

Cell is actively synthesising proteins

DNA replication

Chromosomes are invisible

30

why do you take cells from the root tip when studying mitosis?

Region where mitosis/cell division occurs;

31

When when studying mitosis do you firmly squash the root tip?

To allow light through / make tissue layer thin;

32

A cell under goes mitosis, the first division takes 24 hours and each subsequent one takes 8hours, how many cells are there after 3 days?

128

33

How can you tell a cell has just under gone DNA replication?

Chromosomes are visiable as X shaped structures - 2 sister chromatids joined by a centromere