Meiosis Flashcards
1
Q
____ is preceded by a process of DNA replication that converts each chromosome into two sister chromatids.
A
Meiosis
2
Q
____ is the form of eukaryotic cell division that produces haploid sex cells or gametes from diploid cells.
A
Meiosis
3
Q
Meiosis is the form of eukaryotic cell division that produces ____ from diploid cells.
A
haploid sex cells or gametes
4
Q
____ contains a single copy of each chromosome.
A
Haploid Sex Cells or Gametes
5
Q
____ contain two copies of each chromosome.
A
Diploid cells
6
Q
Meiosis takes the form of ____ followed by ____.
A
- One DNA replication
- Two successive nuclear and cellular divisions
7
Q
____ takes the form of one DNA replication, followed by two successive nuclear and cellular divisions.
A
Meiosis
8
Q
The reproductive cycle of ____ ends when a sperm and egg fuse to form a diploid zygote.
A
Meiosis
9
Q
Meiosis involves two sequential cycles of nuclear and cell division called ____.
A
Meiosis I and Meiosis II
10
Q
Meiosis involves how many cycle of DNA replication?
A
1
11
Q
____ is initiated after the parental chromosomes have replicated to produce identical sister chromatids at the S phase.
A
Meiosis I
12
Q
Meiosis involves ____ and ____ between them.
A
pairing of homologous chromosomes; recombination
13
Q
____ are formed at the end of meiosis II.
A
Four haploid cells
14
Q
There are ____ rounds of chromosome segregation in Meiosis.
A
2
15
Q
There are two rounds of ____ in Meiosis.
A
chromosome segregation
16
Q
Two Rounds of Chromosome Segragation
____ segregates homologs.
A
Meiosis I
17
Q
____ are pair of chromosomes that pair up with each other.
A
Homologs
18
Q
The duplicated paternal and maternal homologs pair up alongside each other and become physically linked by the process of ____.
A
genetic recombination
19
Q
In the ____, duplicated homologs are pulled apart and segragated into the two daughter cells.
A
first meiotic anaphase
20
Q
Two Rounds of Chromosome Segragation
In ____, sister chromatids are pulled apart and segregated to produce haploid daughter cells.
A
Meiosis II
21
Q
TRUE OR FALSE.
Each of the haploid nuclei contain both the maternal and paternal copy of each chromosome.
A
False
Either the maternal or paternal, but NEVER both.
22
Q
____ is also known as the reductional division.
A
Meiosis I
23
Q
Meiosis I is also known as the ____.
A
reductional division
24
Q
Stages of Meiosis
The number of centromeres are equal to the number of chromosomes, and reduced by 1/2 at the end of this stage.
A
Meiosis I
25
In meiosis I, the number of ____ are equal to the number of ____, and are reduced by 1/2.
centromeres; chromosomes
26
____ is subdivided into 5 phases based on chromosomal behavior.
Prophase I
27
Five Phases of Prophase I
* Leptotene (Leptonema)
* Zygotene (Zygonema)
* Pachytene (Pachynema)
* Diplotene (Diplonema)
* Diakinesis
28
In early prophase I, homologs begin to associate along their length in a process called ____.
pairing
29
As prophase progresses, the homologs become more closely ____.
juxtaposed
30
Juxtaposed homologs form a four-chromatid structure called ____.
bivalent
31
____ are formed at several locations in each sister chromatid, resulting in large numbers of DNA recombination events between the homologs.
DNA double-strand breaks
32
DNA double-strand breaks are formed at several locations in each sister chromatid, resulting in large numbers of ____ events between the homologs.
DNA recombination
33
Prophase I leads to reciprocal DNA exchanges called ____.
crossovers
34
# **Phases of Prophase I**
The homologs condense and pair
Leptotene (Leptonema)
35
# **Phases of Prophase I**
Homology search starts to happen
Leptotene (Leptonema)
36
# **Phases of Prophase I**
____ is known as the *thin-threated stage*.
Leptotene (Leptonema)
37
Leptotene is also known as the ____.
*thin-threated stage*
38
# **Phases of Prophase I**
The synaptonemal complex begins to assemble at sites where the homologs are closely associated and recombination events are occurring.
Zygotene (Zygonema)
39
The ____ begins to assemble at sites where the homologs are closely associated and recombination events are occurring.
synaptonemal complex
40
# **Phases of Prophase I**
Chromosomes undergo initial alignment, and will have rough pairing at the end of this phase.
Zygotene (Zygonema)
41
# **Phases of Prophase I**
The complex formed by a pair of synapsed homologus chromosomes is called bivalent or a tetrad.
Zygotene (Zygonema)
42
The complex formed by a pair of synapsed homologus chromosomes is called ____.
bivalent or a tetrad
43
# **Phases of Prophase I**
Continuous condensing of homologs
Zygotene (Zygonema)
44
# **Phases of Prophase I**
Homologs become shorter and thicker
Zygotene (Zygonema)
45
# **Phases of Prophase I**
Where the pairing starts
Zygotene (Zygonema)
46
# **Phases of Prophase I**
____ is known as the *yoked-threated stage*.
Zygotene (Zygonema)
47
Zygotene is known as the ____.
*yoked-threated stage*
48
# **Phases of Prophase I**
The assembly process is complete, and the homologs are synapsed along their entire lengths.
Pachytene (Pachynema)
49
# **Phases of Prophase I**
During this stage, bivalent chromosomes now clearly appear as tetrads.
Pachytene (Pachynema)
50
# **Phases of Prophase I**
Development of synaptonemal complex
Pachytene (Pachynema)
51
During the pachytene phase, ____ starts to develop.
synaptonemal complex
52
Homologs in the pachytene phase are separated with a distance of ____.
100 nm
53
# **Phases of Prophase I**
More intimate arrangement and pairing
Pachytene (Pachynema)
54
# **Phases of Prophase I**
Genetic transfer happens
Pachytene (Pachynema)
55
# **Phases of Prophase I**
____ is known as the *thick-threated stage*.
Pachytene (Pachynema)
56
Pachytene is known as the ____.
*thick-threated stage*
57
# **Phases of Prophase I**
Disassembly of synaptonemal complexes
Diplotene (Diplonema)
58
# **Phases of Prophase I**
Concomitant condensation and shortening of the chromosomes
Diplotene (Diplonema)
59
# **Phases of Prophase I**
Crossover events between non-sister chromatids can be seen
Diplotene (Diplonema)
60
During the diplotene phase, crossover events between non-sister chromatids can be seen as inter-homolog connections called ____.
Chiasmata
61
____ is the exchange of genetic material between two homologous chromosomes.
Crossing over
62
Crossing over process is mediated by the enzyme ____.
recombinase
63
# **Phases of Prophase I**
Recombination is completed by the end of this stage
Pachytene (Pachynema)
64
# **Phases of Prophase I**
____ is known as the *double-threated stage*.
Diplotene (Diplonema)
65
Diplotene is known as the ____.
*double-threated stage*
66
# **Phases of Prophase I**
The final stage of meiotic prophase I
Diakinesis
67
# **Phases of Prophase I**
Marked by terminalization of chiasmata
Diakinesis
68
# **Phases of Prophase I**
The chromosomes are fully condensed, and the meiotic spindle is assembled.
Diakinesis
69
# **Phases of Prophase I**
By the end of this stage, the nucleolus disappears, and the nuclear envelop breaks down.
Diakinesis
70
# **Phases of Meiosis I**
The bivalent chromosomes align on the equatorial plate.
Metaphase I
71
# **Phases of Meiosis I**
The microtubules from the opposite poles of the spindle attach to the pair of homologous chromosomes.
Metaphase I
72
# **Phases of Meiosis I**
The homologous chromosomes separate, while sister chromatids remain associated at their centromeres.
Anaphase I
73
# **Phases of Meiosis I**
Cohesin degradation happens
Anaphase I
74
# **Phases of Meiosis I**
The nuclear membrane and nucleolus reappear, and cytokinesis follows.
Telophase I
75
The re-appearance of nuclear membrane and nucleolus, and the occurence of cytokinesis are collectively called as ____.
diad of cells
76
The stage between two meiotic divisions is called ____ and is generally short-lived.
interkinesis
77
Interkinesis is followed by ____.
Prophase II
78
____ is also known as the *equational division*.
Meiosis II
79
# **Stages of Meiosis**
The number of centromeres and chromosomes remain equal by the end of this stage.
Meiosis II
80
In meiosis II, the number of ____ and ____ remain equal by the end.
centromeres; chromosomes
81
In meiosis II, the number of centromeres and chromosomes remain ____ by the end.
equal
82
The product of Meiosis II are ____.
4 haploid cells
83
____ is completed only at ovulation.
Meiosis I
84
Meiosis I is completed only at ____.
ovulation
85
____ is completed only after the egg is fertilized.
Meiosis II
86
Meiosis II is completed only after the egg is ____.
fertilized
87
____ is the phenomenon when homologs fail to separate properly.
Nondisjunction
88
What is the result of nondisjunction?
* Some gametes lack a chromosome.
* Some gametes have more than one copy of the chromosome.
89
____ increase greatly with advancing maternal age.
Segregation errors
90
# **Mitosis vs. Meiosis**
One division
Mitosis
91
# **Mitosis vs. Meiosis**
Two divisions
Meiosis
92
# **Mitosis vs. Meiosis**
Two daughter cells per cycle
Mitosis
93
# **Mitosis vs. Meiosis**
Four daughter cells per cycle
Meiosis
94
# **Mitosis vs. Meiosis**
Daughter cells genetically identical
Mitosis
95
# **Mitosis vs. Meiosis**
Daughter cells genetically different
Meiosis
96
# **Mitosis vs. Meiosis**
Chromosome number of daughter cell same as that of the parent cell
Mitosis
97
# **Mitosis vs. Meiosis**
Chromosome number of daughter cell half that of the parent cell
Meiosis
98
# **Mitosis vs. Meiosis**
Occurs in somatic cells
Mitosis
99
# **Mitosis vs. Meiosis**
Occurs in germline cells
Meiosis
100
# **Mitosis vs. Meiosis**
Occurs throughout life cycle
Mitosis
101
# **Mitosis vs. Meiosis**
Completes after sexual maturity
Meiosis
102
# **Mitosis vs. Meiosis**
Used for growth, repair, and asexual reproduction
Mitosis
103
# **Mitosis vs. Meiosis**
Used for sexual reproduction, producing new gene combinations
Meiosis
104
____ is a protein that provides structural support for a chromosome.
Histone
105
Histone is wrapped by ____.
DNA
106
A histone wrapped by a DNA is collectively called ____.
Nucleosome
107
____ is the constriction of chromosome.
Centromere
108
____ are fluorescent structures at the end of each chromosome.
Telomeres
109
Functions of Telomere
* Protection from nucleolitic degradation
* Protection from unnecessary recombination
* Chromosome repair
110
____ serve as protection from nucleolitic degradation.
Telomeres
111
____ serve as protection from unnecessary recombination.
Telomeres
112
____ functions in chromosome repair.
Telomere
113
____ pairs of chromosomes are autosomes.
22
114
22 pairs of chromosomes are ____.
autosomes
115
The ____ pair of chromosomes are sex chromosomes.
23rd
116
The 23rd pair of chromosomes are ____.
sex chromosomes
117
The homologous (XX) pair of chromosomes are for ____.
females
118
The non-homologous (XY) pair of chromosomes are for ____.
males
119
The DNA may be composed of ____ nucleotides in a chain.
100,000 to 10,000,000,000
120
____ have large linear chromosomes.
Eukaryotic cells
121
____ have smaller circular chromosomes.
Prokaryotic cells
122
____ has been developed by the Standing Committee on Human Cytogenetic Nomenclature.
International System for Human Cytogenetic Nomenclature (ISCN)
123
____ is the central reference for the description for karyotyping.
International System for Human Cytogenetic Nomenclature (ISCN)
124
Other functions of International System for Human Cytogenetic Nomenclature (ISCN)
* Fluorescence in situ hybridization (FISH)
* Provides rules for cytogenetic findings in laboratory reports
125
Chromosome short arms are called ____.
p (petit)
126
Chromosome longs arms are called ____.
q (queue)
127
Four Types of Chromosomes Based on the Position of Centromere
* Metacentric
* Submetacentric
* Acrocentric
* Telocentric
128
# **Four Types of Chromosomes Based on the Position of Centromere**
The centromere occurs in the center and all the four chromatids are of equal length.
Metacentric
129
# **Four Types of Chromosomes Based on the Position of Centromere**
The centromere is a little away from the center and therefore chromatids of one side are slightly longer than the other side.
Submetacentric
130
# **Four Types of Chromosomes Based on the Position of Centromere**
The centromere is located closer to one end of chromatid therefore the chromatids on opposite side are very long.
Acrocentric
131
____ is a small, round structure, attached by a very thin thread.
Satellite
132
____ is the connection of satellite to the chromatid.
Stalk
133
# **Four Types of Chromosomes Based on the Position of Centromere**
The centromere is placed at one end of the chromatid and hence only one arm.
Telocentric
134
____ are long regions of repetitive non-coding DNA that cap chromosomes to stop replication.
Telomeres
135
____ undergo partial degradation each time a cell undergoes division.
Telomeres
136
____ is a laboratory test where you can see the individual's complete set of chromosomes.
Karyotype
137
Which phase of reproduction is optimal for karyotype viewing?
Metaphase
