Chromosome and Cell Division Flashcards
1
Q
Life depends on the ability of cells to store, retrieve, and translate the genetic instructions required to make and maintain a living organism. This hereditary information can be passed on from a cell to its daughter cells during ___ ___
A
cell division
2
Q
its genetic material is usually concentrated in a specific clear region of the cytoplasm called nucleiod.
A
prokaryotes
3
Q
The prokaryotic (bacteria) genetic material is usually concentrated in a specific clear region of the cytoplasm called
A
nucleoid
4
Q
is a single, circular, double stranded DNA molecule mostly attached to the plasma membrane.
A
bacterial chromome
5
Q
characteristics of The bacterial chromosome
A
single
circular
dsDNA
6
Q
the bacterial chromosome is mostly attached to the ___
A
plasma membrane
7
Q
does bacterial chromosome have histone protein?
A
no
8
Q
Besides the chromosomal DNA many bacteria may also carry extra chromosomal genetic elements in the form of small, circular and closed DNA molecules, called
A
plasmids
9
Q
extra chromosomal genetic elements in the form of small, circular and closed DNA molecules
A
plasmids
10
Q
plasmids are extra chromosomal genetic elements in the form of ___ , ___and ___DNA molecules
A
small
circular
cclosed
11
Q
These generally remain floated in the cytoplasm and bear different genes.
A
plasmids
12
Q
While the ___cell has genetic material in the form of genomic DNA enclosed within the nucleus.
A
eukaryotic
13
Q
Genes or the hereditary units are located on the chromosomes which exist as ___ ___in the non-dividing cell/interphase.
A
chromatin network
14
Q
revealed that during cell division the nuclear material organize themselves into visible thread like structures which were named as chromosomes which stains deep with basic dyes
A
Walter Flemming
15
Q
Walter Flemming in the early 1880s revealed that during cell division the nuclear material organize themselves into visible thread like structures which were named as
A
chromosomes
16
Q
chromosomes are stained with basic/acidic dyes
A
basic
17
Q
The term chromosome was coined by
A
W. Waldeyer-Hartz
18
Q
Chrome in chromosome means
A
coloured
19
Q
soma in chromsome means
A
body
20
Q
chromosome literally means
A
colored bodies
21
Q
can be defined as higher order organized arrangement of DNA and proteins.
A
chromosomes
22
Q
It contains many genes or the hereditary units, regulatory elements and other nucleotide sequences.
A
chromosomes
23
Q
Chromosomes also contain DNA-bound proteins called
A
histones
24
Q
which serve in packaging the DNA and control its functions
A
histones
25
reported that the number of chromosomes in each species is constant
Benden
Bovery
26
suggested that chromosomes are the physical structures which acted as messengers of heredity in 1902
Walter Sutton
Theodor Boveri
27
Each of the chromosomes is composed of ___ chromatids
sister
28
Each of the chromosomes is composed of sister chromatids. It has a “waist line” called
centromere or primary constriction
29
the site where the kinetochore proteins attach
centromere or primary constriction
30
is the site of the spindle fiber attachment.
kinetochore
31
The centromere occupies a middle position with reference to the length of the chromosome.
metacentric
32
The two arms thus resulted are almost equal in length.
metacentric
33
During anaphasic movement in cell division, metacentric chromosomes appear ‘__’ shaped.
V
34
When the centromere is located some distance away from the middle region of the chromosome, one chromosome arm will be shorter than the other.
submetacentric
35
During anaphasic movement, sub metacentric chromosomes appear ‘___’ shaped.
L
36
In this case, the centromere is situated almost near one end of the chromosome.
acrocentric
37
As a result, one arm of the chromosome will be extremely short and the other very long.
acrocentric
38
The centromere is said to occupy a subterminal postion.
acrocentric
39
When the centromere is situated exactly at one end, the chromosome will be having only one long arm.
telocentric
40
chromosomes that are very rare
telocentric
41
There are normally ___copies of each chromosome present in every somatic cell.
two
42
The number of unique chromosomes (n) in such a cell is known as its
haploid number
43
the total number of chromosomes (2n) is its
diploid number
44
'ploid' means
sets
45
is also known as the genome.
haploid set
46
In a ___cell, there are two of each kind of chromosome (termed homologous chromosomes) except the sex chromosomes
diploid
47
In humans there are ___pairs of homologous chromosomes (2n=46). T
23
48
non-sex chromosomes, termed ___
autosomes
49
one pair of homomorphic chromsome called
sex chromosome
50
of the same or similar form.
homomorphic
51
occurring in two or more different forms, especially at different stages in the life cycle.
heteromorphic
52
is a series of events that takes place in a cell as it grows and divides.
cell cycle
53
A cell spends most of its time in what is called
interphase
54
and during this time it grows, replicates its chromosomes, and prepares for cell division.
interphase
55
The cell then leaves interphase, undergoes mitosis, and completes its division. The resulting cells, known as ____ each enter their own interphase and begin a new round of the cell cycle.
daughter cells
56
Nucleus at ___is very distinct and enclosed by a define nuclear membrane
interphase
57
Within the nucleus are one or more small round dense bodies called ___ and a granular network of darkly stained material called ____
INTERPHASE
nucleoli
chromatin
58
At interphase, there are three stages that are not morphologically distinguishable but biochemically distinct.
gap 1
synthesis phase
g2
59
The nucleus and cytoplasm are enlarging toward mature size.
what stage of interphase
g1
60
The cell increases in volume by imbibing water & nutrients and building of new protoplasm.
what stage of interphase
g1
61
what cytoplasmic organelles are formed
endoplasmic reticulum
golgi apparatus
mitochondria
chloroplast
62
The DNA content C becomes 2C after this phase.
s phase
63
Each ___ fiber is replicated or doubled in s phase
chromatin
64
There is active synthesis of RNA and proteins necessary for chromosome synthesis.
what stage
G2
65
Mitotic spindles are also formed.
G2
66
The double chromatin fiber is packed to form
a chromosome, the colored bodies during cell division.
what stage
G2
67
The double chromatin fiber is packed to form
a ___, the colored bodies during cell division.
chromosome
68
is undergone by all somatic cells and sex cells.
mitosis
69
In multicellular organisms, it is a means of increasing the number of cells by replacing worn out tissues.
mitosis
70
In unicellular organisms, it is simple a mode of reproduction
mitosis
71
four distinct stages of mitosis
prophase
metaphase
anaphase
telophase
72
The chromosomes shorten, thicken and become visible as thick rods.
prophase
73
The chromosomes are ___double, each half is a chromatid in prophase
longitudinally
74
Nucleoli and nuclear membrane completely disappear by what stage of prophase.
late
75
In animal cell, this divides and spindle radiates from the aster during prophase.
centriole
76
The nuclear membrane disappears and spindle fiber soon appears.
what stage of mitosis
metaphase
77
The chromosomes which are maximally condensed align at the equatorial plane.
metaphase
78
The spindle fibers attach on the opposite sites of the centromeres.
metaphase
79
The centromeres become functionally double
anaphase
80
The chromatids of the chromosomes begin to move towards the opposite poles.
anaphase
81
The poleward movement of the chromosomes is due to the ___of the spindle fibers attached to the centromeres.
depolymerization
82
Upon reaching the opposite poles, the chromosomes regroup into two nuclear structures.
telophase
83
The chromosomes begin to uncoil & lengthen and finally lose their visible identity.
telophase
84
usually follows mitosis.
cytokinesis
85
In ____, the cytoplasm is divided by cell plate formation where separation starts from the inside of the cell towards the periphery
plants
86
In plants, the cytoplasm is divided by cell plate formation where separation starts from the ___ of the cell towards the ___
inside
periphery
87
In ____, cell cytokinesis occurs by furrowing or cleavage formation that starts from the periphery.
animals
88
In animals, cell cytokinesis occurs by furrowing or cleavage formation that starts from the ___.
periphery
89
In animals, cell cytokinesis occurs by ___ or ___formation that starts from the periphery.
furrowing
cleavage
90
is also preceded by G1, S and G2 of the cell cycle. It consists of two divisions which follow each other in rapid sequence.
meiosis
91
also referred to as reductional division, involves the separation of homologous chromosomes resulting in two cells with haploid chromosome number.
meiosis I
92
involving only the separation of chromatids producing four haploid cells. This is also known as equational division.
meiosis
93
Prophase I has five distinct substages:
leptotene
zygotene
pachytene
diplotene
diakinesis
94
The chromosomes appear as long threads with many bead-like structures (chromomeres) along their length.
leptotene
95
In some plants, the chromosomes are clumped on one side of the nucleus
leptotene
96
the chromosomes are clumped on one side of the nucleus a phenomenon called
synizesis
97
while in some animals, it tends to be drawn towards the part of the nuclear membrane close to the centriole during leptotene
choromosome
98
Synapsis or pairing of homologous chromosomes begins.
zygotene/zygonema
99
The paired chromosomes form a ___consisting of four chromatids.
bivaent
100
The paired chromosomes form a bivalent consisting of four chromatids.
zygotene
101
is very precise so that homologues pair side by side during zygotene
synapsis
102
is formed in between homologous pair that is essential in crossing over.
synaptonemal complex
103
is a meiosis-specific protein structure that forms between homologous chromosomes during prophase I of meiosis, mediating synapsis and facilitating meiotic recombination and crossover formation.
synaptonemal complex
104
The chromosomes are thicker due to further coiling.
what stage of meiosis I
pachytene
105
The two chromosomes in a bivalent are closely appressed.
pachytene
106
Chromatid breaks and their repair occur along the chromosome.
pachytene/pachynema
107
Repairing of breaks may entail exchange of segments between sister and non-sister chromatids in a bivalent.
what stage in prophase I
pachytene
108
This is known as crossing-over which is cytologically observed through formation of chiasma at the point of exchange. Crossing-over generates variation in the population.
pachytene
109
With the synaptonemal complex no longer functional, the longitudinal separation of homologues in a bivalent starts from the centromere and proceeds toward both ends except at the chiasma
what stage of prophase I
diplotene
110
Bivalents are maximally condensed and distributed throughout the nucleus
what stage in prophase I
diakinesis
111
By the end of this stage, nucleolus and nuclear membrane have disappeared, the spindle has formed and Prophase I is completed.
diakinesis
112
The bivalents align at the equatorial plane.
metaphase I
113
The bivalents are so oriented that each homologue is on each side of the metaphase plane with their centromeres attached at the spindle fibers.
metaphase I
114
The univalent (or homologue) in each bivalent separate from each other.
anaphase I
115
Movements of the univalent to the opposite poles is due to depolymerization of the spindle fibers.
what stage of Meiosis
anaphase I
116
The homologues segregate from one another so that each ___ group is composed of haploid number (n) chromosomes
anaphase
117
This process accounts for the reductional phase of Meiosis I.
anaphase I
118
The chromosomes regroup and their structures begin to relax.
telophase I
119
The nuclear membrane as well as nucleolus reappear forming two haploid daughter cells.
Telophase I
120
In some species, no ___happens after Meiosis I.
cytokinesis
121
A brief transitional stage called ____ occurs before the cell proceeds to the next stage.
interkinesis
122
The division proceeds in a manner similar to mitosis except that there are two haploid cells (from meiosis I) that undergo each stage.
meiosis II
123
The chromosomes begin to condense. The nucleus and nuclear member disintegrate in Meosis II
prophase II
124
Spindle fibers are formed and the chromosomes align at the equatorial plane in meiosis II
metaphase II
125
Sister chromatids of a univalent separate and proceed to the opposite poles as individual chromosomes in Meiosis II
anaphase II
126
Chromosomes uncoil and lengthen, nuclear membrane and nucleolus reappear in Meiosis II
telophase II
127
follows, forming four cells with haploid chromosome number.
cytokinesis
128
the production of sperm and eggs
gaemetogenesis
129
During meiosis, two cell divisions separate the paired chromosomes in the nucleus and then separate the chromatids that were made during an earlier stage of the cell’s life cycle, resulting in gametes that each contain __the number of chromosomes as the parent.
half
130
he production of sperm is called
spermatogenesis
131
and the production of eggs is called
oogenesis
132
study how to count gametogeness
+1
