Lec 1 Flashcards
Cell Cycle and Chromosomes (127 cards)
1
Q
composed of DNA, carrying the hereditary information (gene)
A
Chromosome
2
Q
series of events which ncludes the growth, replication, and division of eukaryotic icells
A
Cell Cycle
3
Q
Mitosis occurs in
A
somatic/vegetative cells
3
Q
Flow of biological information
A
DNA > RNA > Proteins
4
Q
Meiosis occurs in
A
gametic (reproductive) cells
5
Q
occurs in somatic/vegetative cells
A
Mitosis
6
Q
occurs in gametic (reproductive) cells
A
Meiosis
7
Q
Cell Theory (5)
A
1.All living things are composed of cells.
2.All cells arise from preexisting cells through cell division.
3.Cells contain hereditary material, which is pass on to daughter cells during cell division.
4.The chemical composition of all cells is quite similar.
5.The metabolic processes associated with life occur within cells.
8
Q
Why does cell division occur?
A
so that multicellular organisms can maintain a stable state, basically for growth, reproduction, and repair.
9
Q
In unicellular organisms cell division occurs for?
A
occurs for the production of new organisms.
10
Q
what happens in G2
A
cell prepares for division
11
Q
what happens in G1
A
cell enlarges before DNA replication
12
Q
“resting” or non-mitotic portion of the cell cycle
A
Interphase
13
Q
what is interphase
A
“resting” or non-mitotic portion of the cell cycle
14
Q
cell prepares for division
A
G2
15
Q
cell enlarges before DNA replication
A
G1
16
Q
The chromatins coils to from chromosomes
A
PROPHASE
17
Q
microtubules forming mitotic spindle
A
PROPHASE
18
Q
Chromosome consisting of two sister chromatids
A
PROPHASE
19
Q
Centromere
A
PROPHASE
20
Q
what happens in prophase
A
The chromatins coils to from chromosomes
– microtubules forming mitotic spindle
– Chromosome consisting of two sister chromatids
– Centromere
21
Q
spindle poles, fragments of nuclear envelope, pair of
Kinetochore
A
PROMETAPHASE
21
Q
The nuclear envelope breaks down. Microtubules connect
the kinetochores to the centrosomes
A
PROMETAPHASE
22
Q
The nuclear envelope breaks down.
A
PROMETAPHASE
23
Microtubules connect
the kinetochores to the centrosomes
PROMETAPHASE
24
The microtubules line up the chromosomes at the cell’s
equator
METAPHASE
25
The chromatids separate, and the new chromosomes (each
derived from one chromatid) move toward the poles
ANAPHASE
26
begins at the plane of constriction forms
Cytokinesis
27
The separating chromosomes reach the poles. The nuclear
envelopes re-form and the chromatin decondenses
TELOPHASE AND CYTOKINESIS
28
main features of the different stages in meiosis
Larix.
29
Occurrence of mitosis
In all the body
cells including the
germ cells
30
Occurrence of meiosis
Only in the germ
(reproductive)
cells
31
Definition mitosis
It is an equational
division
32
Definition MEIOSIS
It is a reductional
division
33
No. of daughter
cells MITOSIS
2
34
No. of daughter
cells MIOSIS
4
35
PROPHASE in MITOSIS
Relatively few changes
36
PROPHASE in MEIOSIS
A series of changes in chromosomes distinguished into 5 substages
37
Relatively few changes
PROPHASE in MITOSIS
38
A series of changes in chromosomes distinguished into 5 substages
PROPHASE in MEIOSIS
39
Chromomeres in MITOSIS
Not visible in prophase
40
Not visible in prophase
Chromomeres in MITOSIS
41
Chromomeres in MEIOSOS
Visible in the leptotene stage of prophase-I
42
Visible in the leptotene stage of prophase-I
Chromomeres in MEIOSOS
43
Synapsis IN MITOSIS
Does not occur
44
Does not occur
Synapsis IN MITOSIS
45
Synapsis IN MEIOSIS
Occurs in zygotene of prophase-I
46
Occurs in zygotene of prophase-I
Synapsis IN MEIOSIS
47
Crossing over IN MITOSIS
Does not occur
48
Does not occur
Crossing over IN MITOSIS
49
Crossing over IN MEIOSIS
Occurs in pachytene stage of prophase-I
50
Occurs in pachytene stage of prophase-I
Crossing over IN MEIOSIS
51
METAPHASE IN MITOSIS
Chromosomes arrange along the equator
52
Chromosomes arrange along the equator
METAPHASE IN MITOSIS
53
METAPHASE IN MEIOSIS
Chromosomes arrange equally on either side of the equator in metaphase-I
54
Chromosomes arrange equally on either side of the equator in metaphase-I
METAPHASE IN MEIOSIS
55
Centromeres in ANAPHASE IN MITOSIS
Each centromere splits into 2
56
Each centromere splits into 2
Centromeres in ANAPHASE IN MITOSIS
57
Centromeres in ANAPHASE IN MEIOSIS
Centromeres do not split in metaphase-I
58
Centromeres do not split in metaphase-I
Centromeres in ANAPHASE IN MEIOSIS
59
Centromeres on METAPHASE IN MITOSIS
Orient towards the equator while chromatids orient towards pole
60
Orient towards the equator while chromatids orient towards pole
Centromeres on METAPHASE IN MITOSIS
61
Centromeres on METAPHASE IN MEIOSIS
Orient towards poles while chromatids orient towards the equator in metaphase-I
62
Orient towards poles while chromatids orient towards the equator in metaphase-I
Centromeres on METAPHASE IN MEIOSIS
63
TELOPHASE IN MITOSIS
Results in the formation of 2 daughter nuclei having the same number of chromosomes as that of parent cell
64
Results in the formation of 2 daughter nuclei having the same number of chromosomes as that of parent cell
TELOPHASE IN MITOSIS
65
TELOPHASE IN MEIOSIS
Telophase-II results in the formation of 2 daughter nuclei, each having half the number of chromosomes as that parent cells
66
Telophase-II results in the formation of 2 daughter nuclei, each having half the number of chromosomes as that parent cells
TELOPHASE IN MEIOSIS
67
CYTOKINESIS IN MITOSIS
Follows immediately after karyokinesis
68
Follows immediately after karyokinesis
CYTOKINESIS IN MITOSIS
69
CYTOKINESIS IN MEIOSIS
May or may not occur at the end of first karyokinesis
70
May or may not occur at the end of first karyokinesis
CYTOKINESIS IN MEIOSIS
71
CHROMOSOMES
molecule of DNA
72
molecule of DNA
CHROMOSOMES
73
sexual reproduction
two gametes fuse to a zygote
74
sexual reproduction
chromosomes of zygote = chromosomes of both gametes
75
why is a reduction of chromosome number necessary during formation of gametes
to avoid a doubling of chromosome numbers in each generation!
76
to avoid a doubling of chromosome numbers in each generation!
why is a reduction of chromosome number necessary during formation of gametes
77
reduction of chromosome numbers
meiosis
78
meiosis
reduction of chromosome numbers
79
DIPLOID
two homologous chromosomes
80
two homologous chromosomes
DIPLOID
81
GAMETE
haploid; one of the two homologous
chromosomes only
82
GAMETE
83
CHIASMATA (prophase 1)
recombination of genes on one
chromosome due to crossing over
84
recombination of genes on one
chromosome due to crossing over
CHIASMATA (prophase 1)
85
POLYPLOID
more than 2 homologous chromosomes
86
more than 2 homologous chromosomes
POLYPLOID
87
GENOME
complete set of non-homologous chromosomes
88
complete set of non-homologous chromosomes
GENOME
89
basic number x
number of non-homologous chromosomes
90
number of non-homologous chromosomes
basic number x
91
gametic number n
chromosome number of gametes
92
chromosome number of gametes
gametic number n
93
somatic number 2n
chromosome numbers of all somatic cells
94
chromosome numbers of all somatic cells
somatic number 2n
95
2n=2x(n=x)
diploid (eq)
96
diploid (eq)
2n=2x(n=x)
97
tetraploid (eq)
2n=4x(n=2x)
98
triploid (eq)
2n=3x(n=???)]
99
Chromosomes aberrations (4)
1. Translocation
2. Deletion
3. Duplication
44. Inversion
100
ANEUPLOIDY
change of basic number x caused by chromosome mutations
101
change of basic number x caused by chromosome mutations
ANEUPLOIDY
102
EUPLOIDY
change of number of genomes
103
change of number of genomes
EUPLOIDY
104
AUTOPOLYPLOIDY
set of chromosomes repeated several times
105
set of chromosomes repeated several times
AUTOPOLYPLOIDY
106
ALLOPOLYPLOIDY
several different chromosome sets
107
several different chromosome sets
ALLOPOLYPLOIDY
108
HYBRIDIZATION;
formation of non-reduced gametes
109
formation of non-reduced gametes
HYBRIDIZATION;
110
highly but not completely sterile
hybridization between closely related species
111
hybridization between closely related species
highly but not completely sterile
112
contribute to the evolution of new species
HYBRIDIZATION;
113
HYBRIDIZATION;
contribute to the evolution of new species
114
IMPORTANCE OF POLYPLOIDY
Polyploid organisms frequently develop...
* bigger cells and leaves: breeding
* reproductive isolation; species formation
* polyploid: more genotypes possible
* often associated with apomixis (asexual propagation through seeds)
* approx. 50% of all plants are polyploid
– grasses (75%)
– bamboo (48-74 chromosomes)
115
Chromosome numbers of Pinatae
* conifers: particularly big chromosomes
– Easy to observe and to count
* Few polyploids
– but: Fitzroya, Sequoia sempervirens
* little polymorphism within families
– but: Podocarpus
116
DIPTEROCARPS
* Different basic numbers (x)
– relation to phylogeny
* Different basic numbers in some genera
– Hopea: 7, 10, 11
* Polyploid species:
– Hopea nutans, Shorea ovalis: 2n=4x=28
– Other Hopea spp.: 2n=3x
* Chromosome polymorphisms:
– Hopea odorata (triploid trees; partially capable of
producing offspring through apomixis)
– Dipterocarpus tuberculatus
117
Chromosome numbers in Casuarina spp.
* approx. 60 species (Malayan and Australian region)
* some important species: C. equisetifolia
* most species diploid with 16 or 18 chromosomes
* chromosome polymorphisms:
– C. nana
– C. littoralis
118
Chromosomes Numbers of Tropical Forest Plants
* limited use of cytology in taxonomy
– Limited variation (Pinatae)
– too complicated (Meliaceae)
* ploidy level important for further studies - e.g., gene markers; inheritance studies
* many polyploid plants also in the tropics - mainly Meliaceae; bamboos, grasses
* polymorphisms of chromosome numbers occur (effect on mating events and fertility???) - Swietenia spp.; Hopea odorata; Casuarina spp
* limited potential for practical applications - PopGR, breeding and conservation of GR of plants
119
* limited use of cytology in taxonomy
– Limited variation (Pinatae)
– too complicated (Meliaceae)
120
– Limited variation (Pinatae)
– too complicated (Meliaceae)
* limited use of cytology in taxonomy
121
polyploid plants also in the tropics
Meliaceae; bamboos, grasses
122
polymorphisms of chromosome numbers occur
Swietenia spp.; Hopea odorata; Casuarina spp
123
Swietenia spp.; Hopea odorata; Casuarina spp
polymorphisms of chromosome numbers occur
124
polymorphisms of chromosome numbers
effect on mating events and fertility???
125
effect on mating events and fertility???
polymorphisms of chromosome numbers
