Brainscape's Knowledge GenomeTM

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


See full index

biology > 2.3 EUKARYOTIC CELL CYCLE AND DIVISION > Flashcards

2.3 EUKARYOTIC CELL CYCLE AND DIVISION Flashcards

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

What is cell theory?

(part of biological molecules)

but its all relevant

A

cells are the basic unit of life
all living things are made up of cells
and all cells come from other cells

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

What is the process of cell division in prokaryotic cells?

A

binary fission

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

What is the process of cell division in eukaryotic cells?

A

Cell division is part of a regulated process called the cell cycle. It conists of three main stages: Interphase, mitosis, cytokinesis
It produces two identical duaghter cells for growth, repair and aesxual reproduction.

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

What is interphase?

A
  • Interphase is always the longest part of the cell cycle (but is variable in length)
  • There are 3 stages that occur in interphase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the three stages of interphases?

A
  • G1 (the first growth phase)
  • S (synthesis)
  • G2 (second growth phase)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

cell cycle

What happens in G1 (Interphase)

A
  • in the nucleus some genes are ‘switched on’ and their base seuquence is transcribed to pre-mRNA molecules

**- The cytoplasm increases in volume (grows) by producing new proteins and cell organelles, including mitochondria and endoplasmic reticulum. **

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

cell cycle

What happens in synthesis?

A
  • In the nucleus, the semi-conservative replication of DNA occurs.
  • New histones are syntehsised and attatch to the replicated DNA in the nucleus.
  • Each chromosome becomes two chromatids attatched at the centromere.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

cell cycle

What happens in G2?

A
  • In the nucleus, replicated DNA is ‘double checked’ for errors and corrected if any errors are found
  • If correction is not possible, the cell is normally halted at this G2 phase.
  • Cell growth continues by further synthesis of proteins and cell organelles.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the stages of mitosis?

A
  • Prophase
  • Metaphase
  • Anaphase
  • Telophase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Mitosis

What happens in prophase?

A
  • chromosomes increasingly shorten and thicken
  • chromosomes become visible (towards the end of prophase)
  • centrioles divide and move to opposite ends of the cell
  • spindle fibres form
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

note on cell structure (TOPIC 1)

What is cytosol?

A

the aqueous component of the cytoplasm of a cell, within which various organelles and particles are suspended.

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

Is the cytosol structureless?

A

No.
Microtubules of a globular protein called tubulin are often present.
Form a network of unbranched hollow cylinders

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

What do microtubules do?

A
  • involved in moving organellles around the cytoplasm
  • form the centrioles found in animal cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Desribe the structure and location of centrioles (normally-not in mitosis)
+what happens to them in mitosis

A
  • occur in pairs
  • normally lie at right angles to each other
  • just outside cell’s nucleus
  • each centriole is composed of nine bundles of microtubules
  • during cell division the centrioles move apart creating a network of micrtubules called the spindle.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is a centromere?

A
  • A narrow region occupying a specific position on each chromosomes.
  • This is the only site on each chromosome to which the microfibres of the spindle can attatch in mitosis.
  • Following DNA replication it temproarily holds together two copies of each chromosome (the chromatids)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What happens in metaphase?

A

Chromosomes line up on the equator

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

What happens in anaphase?

A
  • The spindle fibres contract and shorten
  • Results in the two chromatids being pulled apart by their centromeres to opposite poles of the spindle.
18
Q

What happens in telophase?

A
  • Nuclear membrane reforms
  • Chrosomes de-condense
  • spindle disappears
19
Q

What happens in cytokinesis?

A

cytoplasm divides, forming two identical duaghter cells (clones)

20
Q

Where is mitosis commonly observed?

give an example in mammals and in plants

A

tissues of multicellular organisms that are actively growing.
in mammals: epithelial tissues (skin, intestine lining)
in plants: meristems

21
Q

Define ‘meristems’

A

A group of plant cells that is able to divide by mitosis.
Primary meristems are found at tips of growing shoots and roots.
Secondary meristems are found in woody plants leading to an increased diameter of roots and shoots.

22
Q

CP 3

How could you investigate mitosis?

A

Making a temporary squash preparation of a root tip to investigate the stages of mitosis under a microscope.

23
Q

What is meiosis?

A

A type of cell division that produces four non-identical daughter cells that each have half the number of chromosomes of the parent cell.

24
Q

What is a diploid cell?

A
  • A eukaryotic cell that contains two copies of each chromosome.
  • Is represnted as 2n
  • In sexually reproducing organisms one copy comes from each parent
25
Q

What is a haploid cell?

A
  • A euakaryotic cell that contains only one chromosome from each of its homologous pairs
  • is represented as n
26
Q

What are homolgous chromosomes?

A

A pair of chromosomes in a diploid cell that have the same shape and size and carry the same genes in the same order, although not necessarily the same alleles of each gene.

27
Q

How many divisions are there in meiosis?

A

2

28
Q

Overview of meiosis

Figure 5.8

A
29
Q

What is meiosis?

A

a type of cell division that results in four non identical daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes.

30
Q

An overview of mitosis

A
31
Q

What happens in prophase I

A
  • chromosomes shorten and thicken
  • homologous chromosomes pair up to form bivalents
  • centrioles duplicate
  • chromosomes become visible
  • crossing over occurs- visible as chiasmata
32
Q

What happens in metaphase I

A
  • nuclear membrane breaks down
  • spindle forms
  • bivalents line up on the equator
  • independent assortment*

*random alignment of homologous pairs along the equator

33
Q

What happens in anaphase I

A
  • Homologous chromosomes (pairs) seperate
  • spindle fibres shorten and contact pulling whole chromosomes by their centromeres to opposite ends of the cell

forms n cells

34
Q

What happens in telophase
I

A
  • Nuclear membrane reforms around daughter nuclei
  • chromosomes start to decondense
35
Q

What happens in prophase II

A
  • The chromosomes condense
  • centrioles duplicate
36
Q

What happens in metaphase II

A
  • Nuclear membrane breaks down
  • spindle forms
  • chromosomes attatch by their centromere to the spindle fibres at the equator of the spindle
37
Q

What happens in anaphase II

A
  • The chromatids seperate at their centromere
  • pulled to opposite poles of the cell
38
Q

What happens in telophase II

A

Chromatids (now called chromosomes) decondense.
The nuclear membrane reforms.

39
Q

What is chromosome translocation?

A

part of the chromsomes breaks and rejoins a completely different chromosomes.

40
Q

What is chromosome non-disjunction?

A

The failure of homologous chromosomes to seperate properly during the first division of meiosis. It results in daughter cells (gametes) with too many or too few chromosomes.

41
Q

Polysomy

+ name an example

A

A term used to describe a diploid cell or organism with more than two copies of a particular chromosome.
eg: Downs Syndrome - three copies of chrosome 21 (trisomy)

42
Q

Monosomy

+ name an example

A

A term used to describe a diploid cell or organism with only one copy of a particular chromosome.
eg: Turner’s Syndrome- monosomy of the sex chromosome (only one X)

biology (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions