cell division Flashcards
1
Q
What is a haploid number
A
having one set of chormsomes
2
Q
diploid number
A
having two sets of chromosomes
3
Q
what are the four stages of mitosis
A
prophase, anaphase, metaphase and telophase
4
Q
what is cancer
A
when cells lose the ability to control the rate and number of times mitosis takes place
5
Q
one function of meiosis
A
to produce haploid gametes
6
Q
where does meiosis occur
A
testes and ovaries
7
Q
tissue culture
A
cells grown outside an organism
8
Q
what type of cell division occurs in tissue culture
A
mitosis
9
Q
give an application of tissue culture
A
monoclonal antibodies to treat cancer
10
Q
cell continuity
A
all cells come from pre existing cells
11
Q
cell division
A
cells divide by mitosis of meiosis
12
Q
chromosome
A
coiled threads of DNA (which forms genes) and protein that become visible in the nucleus at cell division
13
Q
chromatin
A
when a cell is not dividing, all chromsomes exist as long, thin threads called chromatin
14
Q
cell cycle
A
changes that take place in a cell during the period between one cell division and the next
15
Q
interphase
A
period when the cell isnt dividing
16
Q
replicate
A
copy
17
Q
cytokinesis
A
final stage in cell division when cell divides in two
18
Q
cancer
A
uncontrolled mitosis
19
Q
mutation
A
a spontaneous change in a gene or chromsome number in a cell
20
Q
carcinogen
A
cancer causing agents
21
Q
centrioles
A
form the spindle fibres leading to cell division
22
Q
spindle fibres
A
thread like structures that pull chromosomes apart
23
Q
cleavage furrow
A
pinching in of cell membrane leading to formation of 2 separate cells
24
Q
cell plate
A
vescicles of cellulose that form between 2 separating plant cells, leading to the formation of 2 separate cell walla
25
describe what happens during anaphase
spindle fibres contract and an equal number of chromosomes is pulled to each pole
26
state the main difference between cells resulting from mitosis and cells resulting from meiosis
cells resulting from mitosis have identical chromosome numbers to the parents, while cells resulting in meiosis have different chromosome numbers to the parents
27
which type of cell division produces cells that are different from the parent cell
meiosis
28
explain the importance of meiosis
produces haploid gametes_ allows for reproduction
| variety in cells - prevents disease
29
where does mitosis take place
somatic cells - hair and nail cells
30
where does meiosis occur
ovaries and testes
31
what is a clone
an identical cell/organism produced by mitosis
32
outline the significance of mitosis in relation to cloning
all growth in cloning is a result of mitosis
33
give an example of the production of clones in nature
asexual reproduction in plants
34
one advantage and one disadvantage of using cloning in agriculture and horticulture
eg. micropropogation of crops eg broccoli
a- cheap way to produce large numbers of exactly similar plants
d- the whole crop is equally susceptable to disease
35
describe what happens in telophase
nuclear membrane forms around each of the two sets of chromosomes
the chromosomes elongate within each nucleus and become chromatin
36
name two possible causes of cancer
chemicals in cigarette smoke ad uv radiation
37
possible methods of decreasing the chances of getting cancer
regular check ups- avoid carcinogenic substances
38
why is cancer more common now than 80 years ago
more exposure to carcinogens
39
in some countries people are tested regularly for common cancers. why is this a good thing
a lot of cancers can be cured if caught early on
40
how many cells are formed when a cell divides by mitosis
2
41
what is mitosis
a form of nuclear division in which one nucleus divides to form two nuclei, each containing the same number of chromosomes with identical genes
42
function of mitosis in a single celled organism
reproduction
43
function of mitosis in a multicellular organism
growth and repair
44
state one way mitosis differs from meiosis
in mitosis two cells are formed, while in meiosis four cells are formed
45
Give the names of two processes involving DNA which take place during interphase
chromosome duplication and uncoiling
46
Describe telophase briefly in a plant cell
Cell plate formation of the two cell walls
47
how much of the cell cycle is interphase
90 percent
48
mitosis
a form of nuclear division in which one nucleus divides to form two nuclei, each containing the same number of genes with identical chromosomes
49
haploid cell
has one set of chromosomes
50
diploid cell
has two sets of chromsomes ie two of each type of chromsome in the nucleus
51
express a cell with a diploid number of 4
2n = 4
52
cell with a haploid number of 4
n=4
53
homologous pair
two chromosomes of similar size with the same sequence of genes
54
how are cells active during interphase
the cell produces new organelles - mitochondria and chloroplasts
it forms chemicals needed for growth - enzymes and other proteins
55
what does the cell do just before interphase
chromsomes go from uncoiled to coiled and produce identical copies if themselves (chromosome duplication)
56
what type of cells does mitosis take place in
somatic (none reproductive) cells
57
ways in which mitosis differs from meiosis
four new cells/nuclei produced
variation/not identical
chromosome number halved
58
name the two stages of the cell cycle
mitosis and interphase
59
state the function of meiosis in multicellular organisms
produces haploid gametes
60
describe what happens during anaphase
spindle fibres contract and the chromosomes are pulled to opposite ends of the cell
61
after telophase of mitosis how do 1.animal cells and 2.plant cells
split in two
1. a cleavage furrow
| 2. cell plates form
62
name the stage of mitosis in which chromatin begins to condense
prophase
63
interphase
the part of the cell cycle during which no cell division takes place
64
in what type of cell does a cleavage furrow form
animal cells
65
two biomolecules that form during interphase
DNA and protein
66
name two organelles replicated during interphase
mitochondrion and chloroplast
67
give two changes that occur in the cell by the end of intephase
chromosomes become thick and coiled and spindle fibres begin to form
68
why do human red blood cells not undergo cell division
they have no nucleus
69
explain why chromosomes are pulled to opposite ends of the cell in anaphase
the spindle fibres contract
70
distinguish between nucleus and nucleolus
nucleus controls the activities of a cell
| nucleolus is found inside the nucleus
71
distinguish between mitochondria and chloroplast
the mitochondria is involved in respiration/making energy
| the chloroplast makes food by photosynthesis
72
how much of the cell cycle does interphase account for
90%
73
cell division in animal cells
cleavage furrow
74
centromere
the point at which the chromosomes are attached in a double stranded chromsome
75
cancer causing genes
oncogenes
76
how many chromosomes in a cell which 2n = 4
4
77
after telophase how do plant cells split in 2
cell plate formation
78
which stage in mitosis does chromatin begin to condense
prophase
79
interphase
the part of the cell cycle in which no cell division is taking place
80
why do red blood cells not undergo cell division
they have no nucleus
81
give to functions of meiosis
to produce haploid gametes and introduce variation
82
give two cellular processes that occur during interphase
chromosome replication and protein synthesis
83
prokaryote
has no nucleus or membrane bound organelles
84
nucleus
controls the activities of the cell
85
nucleolus
found inside the nucleus
86
organ
group of tissues working together to carry out a similar function
87
tissue
group of cells working together to carry out a similar function
88
explain the term diploid number
chromosomes in pairs
89
where are the chromsomes during metaphase
on the equator
