Cell Cycle And Cell Division Flashcards
(142 cards)
1
Q
During the division of cell , ______ and ______ also takes place .
A
DNA replication
Cell growth
2
Q
Although ______ is a continuous process , _____ occurs only during one specific stage in the cell cycle .
A
Cell growth
DNA synthesis
3
Q
Cell growth in terms of _______is a continuous process .
A
Cytoplasmic increase
4
Q
A typical eukaryotic human cell has a cell cycle of _____hours .
A
24
5
Q
Cell cycle of yeast lasts for about -
A
90 minutes
6
Q
The 2 basic phases of cell cycle -
A
Interphase
M Phase /Mitosis
7
Q
In the average life cycle of 24 hours , cell division proper lasts for only about -
A
1 hour
8
Q
The ______ lasts for more than 95% of the duration of the cell cycle .
A
Interphase
9
Q
M phase of cell cycle starts with the _______division called ____ .
A
Nuclear
Karyokinesis
10
Q
Division of cytoplasm called ______ occurs after karyokinesis .
A
Cytokinesis
11
Q
During interphase , the cell is undergoing both ______ and _____ in an orderly manner .
A
Cell growth
DNA replication
12
Q
Interphase is divided into -
A
3 sub phases -
G1
S
G2
13
Q
______ phase corresponds to the interval between mitosis and DNA replication .
A
G1
14
Q
During G1 phase , the cell is ________and _______ but DOES NOT REPLICATE ITS DNA .
A
METABOLICALLY ACTIVE
CONTINUOUSLY GROWS
15
Q
S phase marks the period during which _______ takes place .
A
DNA synthesis or replication
16
Q
During S phase , the amount of ______ per cell doubles .
A
DNA
17
Q
During S phase , there is no increase in _______ .
A
Chromosome number .
At G1 , if the cell had 2n chromosomes , then after S phase , the number will still be 2n .
18
Q
In animal cells , during the S phase , DNA replication begins in the _______ and the _______ duplicates in the cytoplasm .
A
Nucleus
Centriole
19
Q
During G2 phase , _____ are synthesised in preparation for mitosis while ________ continues .
A
Proteins
Cell growth
20
Q
Some cells in animals do not appear to exhibit division . Example-
A
Heart cells
21
Q
The cells that do not divide further ______ G1 phase to enter an INACTIVE stage called QUIESCENT STAGE (G0).
A
Exit
22
Q
G0 stage is achieved when cells exit ______.
A
G1
23
Q
Cells in this stage remain metabolically active but no longer proliferate unless called on to do so .
A
Quiescent stage
24
Q
In ______ , mitotic division is only seen in diploid somatic cells . Against this , ________ can show mitosis in both HAPLOID and DIPLOID cells .
A
Animals
Plants
25
Exception of a animal where mitosis is seen in haploid cells .
Male honey bees
26
This is the most dramatic period of the cell cycle , involving a major reorganisation of virtually all components of the cell .
M phase - mitosis
27
Since the number of ________ in the parent and the progeny is same , mitosis is also called _________.
equational division
28
Mitosis has beeen divided into 4 stages of ______ division .
Nuclear -karyokinesis
29
Prophase of mitosis follows ___ phases of interphase .
S and G2
30
In ______phases the new DNA molecules formed are not distinct but intertwined .
S and G2
31
Prophase is marked by the initiation of _______ .
Condensation of chromosomal materials
32
The centrosome which had undergone duplication in the ______ phase , begins to move towards opposite poles in prophase .
S phase
33
Completion of prophase is marked by -
| Late prophase
Chromosomal material condenses to form chromosomes
Chromosomes are composed of 2 chromatids joined at the centromere .
Centrosomes move to opposite poles .
2 asters along with spindle fibres form mitotic apparatus .
34
During late prophase , each _______ radiates out MICROTUBULES called ASTERS .
Centrosome
35
Mitotic apparatus consists of -
2 asters together with spindle fibres
36
Disappearance of organelles occurs during late/early prophase .
Late
37
Difference between early and late prophase .state different events .
Early - initiation of chromosome condensation ; centrosome moves to opposite poles
Late- compact chromosomes formed wth sister chromatids joined at centromere ; centrosome radiates out asters ; organelles disappear ( including nucleolus and nuclear envelope )
38
Nucleolus and nuclear envelope disappears during -
Late prophase ( end )
39
______ marks the start of 2nd phase of mitosis - metaphase .
Complete disintegration of nuclear envelope
40
In _____ phase , chromosomes are spread throughout the cytoplasm of the cell .
Metaphase
41
By this stage , condensation of chromosomes is completed and they can be observed clearly under the microscope .
Metaphase
42
Metaphase is the best stage to study the _______ of chromosomes .
Morphology
43
_______ chromosome is made up of 2 sister chromatids joined at the centromere .
Metaphase
44
Small disc shaped structures on the surface of centromeres are called _____ ans they can be seen in ________ phase .
KINETOCHORES
| Metaphase - for attachment of spindle
45
KINETOCHORES are formed by __________ during ________ phase
Spindle fibres
| Metaphase
46
______ serve as sites of attachment of spindle fibres .
KINETOCHORES
47
_______ phase is characterised by on chromatids of each chromosome connected by its kinetochore to spindle fibres from one pole and its sister chromatid connected by its kinetochore to spindle fibres from opposite pole .
Metaphase
| Arranged at equator
48
The plane of allignment of the chromosomes at metaphase is referred to as ______ .
Metaphase plate
49
Features of metaphase -
Spindle fibres attach to KINETOCHORES of chromosomes .
| Chromosomes aligned at the equator
50
During anaphase , daughter chromatids are referred to as __________.
Daughter chromosomes of the future nuclei
51
What happens in early anaphase ?
Each chromosome is split simultaneously and the 2 daughter chromatids migrate towards opposite poles .
52
As each chromosome moves away from the equatorial plate , the _______ of each chromosome remains directed towards the POLE and hence at the LEADING EDGE , with the _______ of the chromosome trailing behind .
Centromere
| Arms
53
Chromatids move to opposite poles during late/early anaphase .
Late
| Early - chromatids separate
54
At the beginning of telophase , _______ that have reached opposite poles DECONDENSE and ___________ .
Chromosomes
| Lose their individuality
55
Decondensation of chromosomes occurs in early /late telophase .
Early
56
In early telophase , individual chromosomes can no longer be seen and a set of ________ tends to collect at each pole
Chromatin material
57
Nucleolus , Golgi complex and ER reform in -
Late telophase
58
Segregation of duplicated chromosomes into daughter nuclei is called -
Karyokinesis
59
In an animal cell ,cytokinesis is achieved by the appearance of a ________ in the ________ .
Furrow
| Plasma membrane
60
Formation of a furrow in animal cell is from ______ to _______ .
Inside/outside
Outside to inside
| Centripetal
61
In plant cells , wall formation starts in the _______ of the cell and grows ______ to meet the existing lateral walls .
Centre
Outward
( centrifugal )
62
Formation of a new ________ begins with the formation of a simple precursor called the CELL PLATE in plant cells .
Cell wall
63
The cell plate ( precursor of cell wall ) in plat cells represents ______ between the walls of the two adjacent cells .
Middle lamella
64
At the time of CYTOPLASMIC DIVISION , organelles like ______ and ______ get distributed between the 2 daughter cells .
Mitochondria
| Plastid
65
In some organelles ______ is not followed by _______ , as a result of MULTINUCLEATE condition arises .
Karyokinesis
| Cytokinesis
66
The multinucleate condition leads to the formation of ________.
Syncytium
| Liquid endosperm in coconut
67
Mitosis is usually restricted to the ______ cells only .
Diploid
68
In some ____ and some social ______ haploid cells also divide by mitosis .
Lower plants
| Social insects
69
The growth of ________ organisms is due to mitosis .
Multicellular
70
Cell growth results in disturbing the ratio between _____ and ______.
Nucleus
| Cytoplasm
71
It becomes essential for the cell to divide and restore the ______ ratio , when it is disturbed due to cell GROWTH .
Nucleo-cytoplasmic ratio
72
Meiosis insures the production of _____ phase in the life cycle of sexually reproducing organisms .
Haploid
73
________ restores DIPLOID phase in the life cycle of sexually reproducing organisms .
Fertilisation
74
We come across meiosis during _______ in plants and animals .
Gametogenesis
75
Meiosis involves 2 sequential cycles of ____ and _______ but only a single cycle of _________.
Nuclear division
Cell division
DNA replication
76
DNA replication occurs how many times in meiosis ?
1
77
Meiosis 1 is initiated after the parental chromosomes have replicated to produce identical sister chromatids at the _______ phase .
S
78
Meiosis involves pairing of ______ chromosomes .
Homologous
79
Meiosis involves RECOMBINATION between _______.
Non-sister chromatids of homologous chromosomes
80
4 haploid cells are formed at the end of ______.
Meiosis 2
81
Meiosis I is initiated at the ______ phase .
S
| When sister chromatids are formed from chromosomes
82
Prophase of ______ is typically LONGER and MORE COMPLEX as compared to prophase of ______ .
Meiosis 1
| Mitosis
83
Prophase 1 of meiosis 1 is subdivided into 5 phases based on -
Chromosomal behaviour
84
5 subdivisions of prophase 1 :
```
Leptotene
Zygotene
Pachytene
Diplotene
Diakinesis
```
85
Prophase of the first meiotic division is typically _______ and ________ when compared to prophase of MITOSIS .
Longer
| More complex
86
During ___ stage , chromosomes become gradually visible under a light microscope .
Leptotene
87
The compaction of chromosomes continues through _______.
| stage of prophase 1
Leptotene
88
What happens during the first phase of prophase 1 ?
Leptotene - compaction of chromosomes continues
89
Leptotene is followed by -
Zygotene
90
During ______ , chromosomes starts pairing together . ( stage of prophase 1 )
Zygotene
91
Pairing of chromosomes is called ______ and occurs during _____ .
Synapsis
| Zygotene
92
Such paired chromosomes as seen during ZYGOTENE after synapsis are called ________ .
Homologous chromosomes
93
ELECTRON MICROGRAPHS of this stage indicate that synapsis is accompanied by the formation of complex structure called SYNAPTONEMAL COMPLEX .
Zygotene
94
The complex formed by a pair of SYNAPSED HOMOLOGOUS CHROMOSOMES is called a _______ or _____ .
Bivalent
| Tetrad
95
Bivalent or tetrad formed in zygotene are clearly visible during which stage ?
Pachytene - visible
| Zygotene - formed
96
The ______ stages of prophase 1 are relatively shorter as compared to PACHYTENE .
1st two - leptotene and zygotene
97
Homologous chromosomes are formed during _______ (stage of prophase 1)
Zygotene
| Synapsis -> homologous chromosomes ->synaptonemal complex -> bivalent /tetrad
98
During this stage pf prophase 1 , 4 CHROMATIDS of each bivalent chromosomes become distinct and clearly appear as TETRAD ( bivalent )
Pachytene
99
Pachytene phase is characterised by the appearance of __________ .
Recombination nodules
100
What are recombination nodules and and when do they appear ?
Sites at which crossing over occurs between non-sister chromatids of homologous chromosomes .
They appear during pachytene
101
– – – – –Is the exchange of genetic material between two homologous chromosomes .
Crossing over
102
Crossing over is also an – – – – – mediated process and The enzyme involved is called – – – – – .
Enzyme -mediated
| Recombinase
103
________ leads to recombination of genetic material on the 2 chromosomes .
Crossing over .
104
_______ is an enzyme-mediated process .
Crossing over - recombination
105
________ is completed at the end of PACHYTENE .
Recombination between HOMOLOGOUS chromosomes
106
Recombination occurs during _______ , leaving the chromosomes linked at the sites of CROSSING OVER .
Pachytene
107
The beginning of ________ is recognised by the DISSSOLUTION of SYNAPTONEMAL complex .( stage of prophase 1)
Diplotene
108
_______ is recognised by the tendency of the RECOMBINED homologous chromosomes of the BIVALENTS to separate from each other except at the sites of cross overs .
Diplotene
109
X -shaped structures called CHIASMATA are formed during -
Diplotene
110
Longest stage of prophase 1 -
Diplotene - can last for months or years in oocytes of some vertebrates
111
Which stage of prophase 1 can last for months or years in the OOCYTES OF SOME VERTEBRATES ?
Diplotene
112
The final stage of meiotic prophase 1 is -
Diakinesis
113
________is marked by terminalisation of chiasmata
Diakinesis
114
Diplotene is characterised by ______ and diakinesis is recognise by ______.
Dissolution of synaptonemal complex
| Terminalisationof chiasmata
115
During this phase of prophase 1 , chromosomes are fully condensed and the meiotic spindle is assembled to prepare the homologous chromosomes for separation .
Diakinesis
116
During diakinesis , _______ is assembled to. Prepare the homologous chromosomes for separation .
MEIOTIC spindle
117
What happens at the end of diakinesis ?
Nucleolus disappears and nuclear envelope also breaks down
118
_______ stage of prophase 1 represents transition to metaphase 1.
Diakinesis
119
During which phase of meiotic prophase 1 , homologous chromosomes are prepared for separation ?
Diakinesis
120
The ______ chromosomes align on the equatorial plate during metaphase 1 of meiosis 1 .
Bivalent
121
During metaphase 1 MICROTUBULES from the opposite poles of the spindle attach to the KINETOCHORE of ________.
Homologous chromosomes
122
During metaphase 2 of meiosis 2 , MICROTUBULES from the opposite poles of the spindle get attached to the KINETOCHORE of _________.
Sister chromatids
123
During _______ of meiosis , HOMOLOGOUS CHROMOSOMES separate , while sister chromatids remain associated at their centromeres .
Anaphase 1
124
Dyad of cells appears in ______ stage .
Telophase 1 of meiosis 1
125
Tetrad of cells appear in _______.
Telophase 2 of meiosis 2
126
During telophase 1 , _________ and ________reappear and ________ follows .
Nuclear membrane
Nuceolus
Cytokinesis
127
During telophase 1 , nucleolus and nuclear membrane reappears , cytokinesis follows and this is called as ________ .
Dyad of cells
128
The stage between 2 meiotic divisions is called _______.
Interkinesis
129
Interkinesis is generally _____ lived .
Short
| Interphase - long
130
There is replication of DNA during interkinesis . T/F
F . No replication of DNA during interkinesis as against that of interphase
131
Interkinesis is followed by -
Prophase 2
132
Which is simpler - prophase 1 or 2 of meiosis .?
2
133
Meiosis 2 is initiated immediately after -
Cytokinesis , usually before chromosomes have fully elongated .
134
meiosis 1/ 2 resembles a normal mitosis .
2
135
What happens by the end of prophase 2 ?
Nuclear membrane disappears
| Chromosomes again become compact
136
Pairing = - ———- And it occurs in which phase ?
Synapsis
| Zygotene
137
Definition of synapsis and crossing over ?
Synapsis - formation of homologous chromosomes . Zygotene
| Crossing over - exchange of genetic material between 2 homologous chromosomes. Pachytene
138
Crossing over = - ——- and it occurs in ?
Recombination
| Pachytene
139
Non -sister chromatids are involved in -
| Homologous chromosomes are involved in -
Recombination -crossing over
| Synapsis - pairing
140
Bouquet stage occurs in which stage of prophase 1 ?
Leptotene
141
Part of plant suitable for the study of meiosis -
Anther
142
In meiosis , how many cycles of chromosomal division occurs ?
1
