Brainscape's Knowledge GenomeTM

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


See full index

A-Level Biology B > 2.3 Eukaryotic Cell Cycle + Division > Flashcards

2.3 Eukaryotic Cell Cycle + Division Flashcards

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

describe the difference between DNA normally and DNA during cell division

A

normally, DNA is all tangled

during cell divison, DNA condenses and appears as visible chromosomes

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

describe the process of DNA forming a visible chromosome

A
  1. DNA is a double helix
  2. DNA wraps around histone proteins to form a nucleosome
  3. nucleosome attaches into chromatin
  4. chromatin coils and supercoils and condenses into a visible chromosome
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

describe, in order, the events of the cell cycle

A 
during interphase:
G1- cell assimilates molcules
    - cell grows
S-phase- semi-conservative DNA replication
             -replication of DNA
G2- cell synthesis of more organelles
during mitosis:
prophase
metaphase
anaphase
telophase
cytokinesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

give 4 key points of mitosis

A
  • 2 new daughter cells made
  • genetically identical to parent cells
  • used for growth + replacement
  • asexual reproduction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what happens during interphase in mitosis

A

cellular organelles double in number, the DNA replicates, and protein synthesis occurs. the chromosomes are not visible and the DNA appears as uncoiled chromatin

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

what happens during prophase in mitosis

A
  • nuclear membrane and nucleolus break down
  • centrioles migrate to opposite poles
  • chromatin condenses to form visible chromosomes
  • spindle fibres start to form
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what happens during metaphase in mitosis

A
  • chromosomes attach singly to the equator by centromere

- centromere attaches them on to the spindle fibres

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

what happens during anaphase in mitosis

A
  • centromeres replicate

- sister chromatids split and move to opposite poles

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

what happens during telophase in mitosis

A
  • nuclear membrane and nucleolus reform
  • centrioles move away from poles
  • chromatins reform (chromosomes decondense)
  • spindle fibres break down
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

give 3 ways that growth can be defined as

A

a permanent increase in number of cells
a permanent increase in the mass of an organism
a permanent increase in the size of an organism

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

what are the three aspects of growth

A

cell division
assimilation
cell expansion

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

how are worn out or damaged cells replaced

A

by mitosis

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

describe asexual reproduction

A

involves one parent
no gametes involved
quicker than sexual reproduction
clones are genetically identical to parent
useful for extreme environments or solitary organisms
lots of different methods

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

describe sexual reproduction

A 
requires two parents 
fusion of gametes occurs
gametes are produced by meiosis
more complex organisms
offspring show genetic variation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

describe binary fission as a process of asexual reproduction

A

involves mitosis and cytokinesis to make 2 offspring

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

describe spores as a process of asexual reproduction

A

involves mitosis and production of asexual spores- each spore grows into a new individual

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

describe regeneration as a process of asexual reproduction

A

some organisms can replace body parts when lost

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

describe bud production as a process of asexual reproduction

A

outgrowth from parent organism- a smaller, genetically identical organism is produced that then detaches and becomes independent

19
Q

describe new plant structures as a process of asexual reproduction

A

vegetative propagation occurs in flowering plants. a new plant is propagated from the parent

20
Q

is a gamete haploid or diploid

A

haploid

21
Q

define homologous

A

same genes in the same places

22
Q

what are the male gamete and site of production in animals

A

sperm cells in testes

23
Q

what are the male gamete and site of production in plants

A

pollen in anther

24
Q

what are the female gamete and site of production in animals

A

ovum in ovaries

25
Q

what are the female gamete and site of production in plants

A

ovum in ovaries

26
Q

give a summary of the two stages of meiosis

A

MEIOSIS I
normal interphase
different PMAT to mitosis

MEIOSIS II
no S-phase in interphase
no semi-conservative DNA replication
PMAT is the same as mitosis

27
Q

what are the end products of meiosis

A

four genetically identical haploid gametes

28
Q

describe interphase of meiosis I

A

same as mitosis

G1 , s-phase and G2 occur

29
Q

describe prophase of meiosis I

A

nuclear membrane and nucleolus break down
centrioles migrate to opposite poles
chromatin condenses to form visible chromosomes
homologous chromosomes form bivalents
crossing over occurs; where nits of maternal and paternal chromosomes are cut and joined at random points called chiasma

30
Q

describe metaphase of meiosis I

A

independent assortment occurs; either of a pair of homologous chromosomes, maternal or paternal, can move to either pole

31
Q

describe anaphase of meiosis I

A

whole chromosomes move to opposite poles

32
Q

describe telophase of meiosis I

A

centrioles move away from poles
nuclear membrane and nucleolus reform
chromatin reforms
spindle fibres break down

33
Q

describe interphase of meiosis II

A

there is G1 and G2 but no s-phase so no semi-conservative DNA replication occurs

34
Q

describe prophase of meiosis II

A

nuclear membrane and nucleolus break down
centrioles migrate to opposite poles
chromatin condenses to form chromosomes
spindle fibres start to form

35
Q

describe metaphase of meiosis II

A

chromosomes attach singly to the equator by centromere

centromere attaches them on to the spindle fibres

36
Q

describe anaphase of meiosis II

A

centromeres replicate

sister chromatids split and move to opposite poles

37
Q

describe telophase of meiosis II

A

centrioles move away from poles
nuclear membrane and nucleolus reform
chromatin reforms
spindle fibres break down

38
Q

what is a chromosomal mutation

A

a change in the large scale structure of a chromosome

39
Q

describe the effect of a non-disjunction mutation on meiosis

A

during anaphase of meiosis II, the sister chromatids should split and move to opposite poles
in non-disjunction mutations, there is a failure of chromosomes splitting so both chromatids go to one poke

40
Q

what effect does a non-disjunction mutation have on the gametes

A

one gamete will have two copies of a chromosome whereas another gamete will have none.

41
Q

define aneuploidy

A

too little or too many chromosomes

42
Q

give two examples of aneuploidy

A

trisomy

monosomy

43
Q

what are the consequences of a non-disjunction mutation

A

it can be fatal

can cause Down’s syndrome, which is trisomy @ 21st chromosome pair

A-Level Biology B (43 decks)

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