Brainscape's Knowledge GenomeTM

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


See full index

Life Sciences > Mitosis and Meiosis > Flashcards

Mitosis and Meiosis Flashcards

1
Q

Where are the chromosomes found

A

in the nucleus

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

what do chromosomes consist of

A

DNA

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

What are histones

A

Double helix DNA coiled around proteins

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

What does the chromosome appear as during interphase

A

chromatin network

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

What happens during the division of DNA

A
  • the DNA shortens and thickens

- it becomes a chromosome

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

What are sister chromatids

A

2 identical chromosome units

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

What are the sister chromatids connected by

A

A centromere

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

How many chromosomes do humans have

A

46

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

How many chromosomes does maize have

A

20

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

The more chromosomes a type of organism has the more _______ the organism is

A

complex

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

What is the homologous chromosome pair

A

the combination of the mother and father chromosome pair

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

Why is the number of chromosomes of the organism (sexually producing) always an even number

A

it consists of 2 sets of chromosomes

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

Chromosomes in each set are usually similar in what 3 factors

A
  • size
  • shape
  • genetic composition
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is mitosis

A

Type of cell division in which one cell divides to produce 2 new cells that are genetically identical

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

what are the 3 functions of mitosis

A
  • growth of an organism
  • replacement of worn/damaged tissue
  • reproduction of unicellular organisms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

List the 5 phases of mitosis

A

interphase, prophase, metaphase, anaphase, telophase

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

Explain the process of interphase

A
  • cells normal metabolic response occurs
  • cell does what is was meant to do
  • chromatin network is always visible
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Explain the process of Prophase

A
  • chromatin NW shortens and thickens
  • DNA replication already occurred therefore there are 2 sets of identical DNA molecules
  • chromosomes become visible
  • nuclear mem begins to disappear and nucleolus disintegrates
    nuclear plasma changes to a gel state
  • cell organelles move away from the nucleus
  • centrioles double and move to opposite poles
  • Spindles form between centrioles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Explain the process of Metaphase

A

Chromosomes are arranged on the equitorial plane of the cell so that the centromere connecting 2 chromatids lies on a spindle

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

Explain the process of Anaphase

A
  • spindles shorten
  • centromere divides into 2
  • chromatids separate
  • chromatids move to opposite poles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Explain the process of Telophase

A
  • daughter chromosomes uncoil to form chromatin NW
  • DNA of 2 cells are identical to one another
  • nuclear membrane and nucleolus reappear
  • division of the cytoplasm occurs (ensures cells are identical)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Provide a definition for cytokinesis

A

division of the cytoplasm occurs so that the 2 cells formed are identical to each other.

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

Definition for meiosis

A

Reduction division that takes place in the reproduction organs of animals and plants where the chromosome number in each cell is halved (diploid to haploid)

24
Q

During mitosis ________ are formed in animals and ______ are formed in plants

A

Gametes and spores

25
What percentage of the cells time is spent in interphase
90%
26
During which phase does DNA replication occur
Interphase
27
Name the 2 distinct stages of meiosis
- meiosis 1 and meiosis 2
28
Explain the process during meiosis 1
chromosome number is halved and the genetic material exchanges and forms 2 identical cells
29
Explain the process during meiosis 2
these 2 daughter cells undergo normal mitotic processes (daughter chromatids separate) to form 4 unidentical daughter cells)
30
explain the process of prophase one in meiosis 1
- chromatin NW shortens and thickens - chromatin becomes visible as chromosomes - homologous chromosome arrange themselves in pairs - 2 chromosomes of each homologous pair arrange tightly to form a bivalent - each chromosome of bivalent divides longitudinally into 2 identical chromatids (sister chromatids)
31
Name the the place where chromatids cross over
Chiasma
32
What occurs in crossing over
genetic info is exchanged between maternal and paternal chromosomes
33
Explain the process of crossing over
- centrioles move to opposite poles - spindle develops from the centrioles - nuclear membrane disintegrates
34
explain the process of metaphase one in meiosis 1
- bivalent arranges in a row on the equator (lie in a double row) - lie in a double row - centromere attaches to the spindles formed by the centrioles.
35
explain the process of anaphase one in meiosis 1
- spindle fibers contract, shorten and pull chromosomes towards the poles - homologous chromosomes separate cytokinesis
36
Explain why independent, random division of maternal and paternal chromosomes is able to take place
due to the homologous chromosomes seperating.
37
explain the process of telophase one in meiosis 1
- chromosomes group themselves at the poles - spindle fibers disappear - nuclear membrane forms around each group of chromosomes and a nucleus forms I each cell nucleus. - cytokinesis is completed and 2 unidentical daughter cells are formed - each daughter cell posses 1 chromosome of each homologous oar
38
explain the process of prophase 2 in meiosis 2
- 2 chromosomes in each of the daughter cells now consists of 2 unidentical chromatids connected by a centromere - nucleolus and the nuclear membrane disintegrate - 2 centrioles move to poles - spindle fibers form (pole to pole)
39
explain the process of metaphase 2 in meiosis 2
- chromosomes arrange w their centromers on equaotr - chromsome centromere attaches to spindle fibers - 2 chromatids arranged on either side of equator
40
explain the process of anaphase 2 in meiosis 2
- centromere divided into 2 - 2 unidentical chromatids break away from one another - spindle fibers shorten and pull the chromatids to opposite poles - chromatids at each pole are known as daughter chromomes - cytokinesis occurs
41
explain the process of telophase 2 in meiosis 2
- chromatids group together at 2 poles of 2 cells - spindle fibers disappear - nuclear mem forms around each chromosome and a nucleolus forms in each nucleus - cytokinesis occurs - after cytokinesis (4 daughter cells)
42
State what happens to males in telophase 2
the daughter cells develop into sperm
43
state what happens to females in telophase 2
of the 4 daughter cells, 3 disintegrate and the 1 becomes a ovum
44
state 3 reasons why meioisis is such an important process
- leads to formation of haploid gametes/spores - halving effect prevents doubling effect thus chromosome number maintained in generations - leads to genetic variation
45
Explain how crossing over and exchange of genetic material during prophase 1 serves as a mechanism to introduce genetic variation by
each gamete of an individual carries different gene combo's
46
Explain how random arrangement of chromosomes on the equator can serve as a mechanism to introduce genetic variation
homologous chromosomes separate their grouping and therefore it leads to greater variation.
47
How does random fertilization promote genetic variation
the sperm that fertilizes is completely random
48
How do mutations cause variation?
It changes the genetic composition thus creating difference
49
What are the 2 types of errors during meiosis
- non- disjunction | - down syndrome
50
What are the 2 types of results of non-disjunction
- aneuploidy | - polyploidy
51
What is non-disjunction errors of meiosis
- incorrect distribution of chromosomes/chromatids - during A1 one of the homologous chromosomes don't divide - during A2 sister chromatids of one or more chromosomes don't divide.
52
What is the difference between Aneuploidy and Polyploidy
aneu= presence of an extra chromosme or absence in a gamete polyploidy= presence of an extra set of chromomes or absence in a gamete
53
What is the other term for down syndrome
Trisomy 21
54
List the errors that occur during meiosis that result in down syndrome
- during Anaphase 1 chromosome 21 doesn't divide | - during anaphase 2 the chromatids of chromosome 21 don't separate
55
Name some features of down syndrome
- mental retardation - flat facial features - short - large head - abnormal ear shape - smallmouth and nose - reduced muscle tone - heart defects - happy and loving nature

Life Sciences (16 decks)

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