Cell Reproduction Exam 3 Flashcards
1
Q
- flora lizard explain
A
offsrping derived genes solely from her = parthenogenesis - production of offspring by female without involvement of a male
2
Q
- cell division def
A
two daughter cells - genetically identical to each other and the parent cell (mitosis) - same amount of DNA
3
Q
- chromosomes
A
structure that contain most of the cell’s DNA - form before it divides & duplicate - one set to each daughter cell
4
Q
- important roles of cell division
A
replace damaged or lost cells - also reproduction ie ameobas
5
Q
- asexual reproduction
A
does nto involve fertilization of an egg by sperm
6
Q
- sexual reproduction
A
requires fertilization of egg by slerm (gametes)
7
Q
- meiosis/mitosis roles
A
meiosis of reporduction (sexual orgs) and mitosis for growth / maintenance
8
Q
- chromatin
A
chromosomes composed of this - roughly equal amounts of DNA / proteins - most of time - chromosomes thin stretched out fibers
9
Q
- a big part of DNA packaging
A
winding it around the histones
10
Q
- sister chromatids
A
result of DNA duplication before a cell divides - side by side
11
Q
- centromere what is
A
where sister chromatids join together at the waist
12
Q
- explain sister chromatid separation + example
A
once separated each is a full chromosome ie skin cell 46 duplicated chromosmes → 46 single chromosomes
13
Q
- cell cycle def
A
ordered sequence of events that extends from time a cell is first formed to its division
14
Q
- most of cell time in what phase
A
interphase - cell performs its normal function ie stomach enzymes -
15
Q
- what is cell doing in interphase
A
cell doubles everything in its cytoplasm - increases protein supply - grows - lasts 90% of cell cycle
16
Q
- most important event in interphase
A
S phase - chromosome duplication - DNA EXACTLY doubled
17
Q
- explain G1/G2
A
before and apfter S phase - in G2 each chromo is double with sister chromatids
18
Q
- part of cycle when cell actually dividing
A
mitotic M phase with: mitosis everything divded/evenly distributed // cytokinesis - cytoplasm spliced apart
19
Q
- elements of G2
A
cell contains 2 centrosomes - chromos duplicated but still as loose chromatin
20
Q
- chromosome movements depend on what
A
mitotic spindle - grow from centrosomes
21
Q
- 4 main stages of mitosis
A
prophase - metaphase - anaphase - telophase
22
Q
- 4 changes in prophase
A
1 chromatin → chromosome in nucleus 2 mitotic spindle forms as microtubules grow 3 nuclear envelope braks into pieces 4 spindle microtubules attach to centromeres on chromos - move them to center
23
Q
- metaphase changes
A
centromeres line up all of the chromos bw 2 poles - pull toward opposites keeps them in centre
24
Q
- anaphase 3 changes
A
sister chromosomes separate → 2 full chromos // spindle microtubles attached shorten to move apart chromos // microtubels not attached lengthen to push apart cell
25
- telophase + cytokinesis 3 steps
2 groups of chromos have reached opposite ends ofthe cell // nuclear envelopes form - chromos uncoil - spindle disappears - MITOSIS ENDED // cytokinesis furrow or plate finishes
26
- animal cell vs plant cytokinesis
animal cleavage furrow // plant cell plate from vesicles
27
- cell cycle control system
cycle normally halts within G1 phase - unles gets go ahead
28
- what is cancer
disease of cell cycle - cell undergoes transformation from MUTATION
29
- tumor def
abnormally growing mass of cells
30
- benign tumour def
lump that stays at original site
31
- malignant tumour
has begun to spread to neighbouring tissues = cancer - the spread = metastasis
32
- cancer treatment types
(slash burn poisont) radiation therapy/chemotherapy
33
- somatic cell def + eg
typical body cell ie in humans 46 chromos
34
- karyotype def
display of chromos in metaphase organized into matching pairs
35
- homologous chromos
pair resemble in length and centromere position - carry genes CONTROLLING same characteristics - 2 homos may have DIFFERENT VARIATIONS of the genes
36
- human chromo arrangment
22 homo pairs (autosomes) + 23rd sex X Y pair - 23 pairs total homologous
37
- sex chromos male/female
XY male XX females
38
- explain diploid orgs
all body cells contain PAIRS fo homologous chromos - 2n - ie 46 in humans
39
- exceptions of 2n diploid in humans
gametes - single 23 chromos - 22 autosomes + either X or Y
40
- haploid explain + eg
only one chromo set - n - ie n number 23
41
- explain fertilization
haploid sperm fuses with haploid egg = diplodi zygote - 2 sets chromos = 46 in humans
42
- can all cells in body trace back to zygote
yes
43
- 3 overview steps of meiosis
interphase chromos duplcated 2// meiosis I - homologous pairs separate (each still doubled) // meiosis II - sister chromatids separate = 4 daughter cells - haploid - single chromo from homo pair
44
- meiosis def
process of cell division produces haploid gametes in diploid organisms - with exchange of genetic material (reduction in DNA by half)
45
- how long do sister chromatids remain together meiosis
anaphase of meiosis II
46
- interphase meiosis
chromosomes duplicate - so chromos with chromatids
47
- 3 steps prophase I meiosis
proteins cause homologous chromos to stick together in pairs // chromatids in homologous chromos - crossing over happens //spindle forms - pairs move to center
48
- metaphase 1 explain
homo pairs aligned in cell - spindles pull homologous pairs apart
49
- anaphase I explain
INDEPENDENT ASSORMENT - homo chromosomes migrate to poles of cell - sister chromos still together (unlike mitosis)
50
- telophase I + cytokinesis explain
chromos at poles of cell - haploid chromo set in DUPLICATE form - 2 haploid daughter cells form
51
- meiosis II big idea
meiosis II same as mitosis - but starts with HAPLOID cell with NO CHROMO DUPLICATION (already duplicated)
52
- prophase II
spindle forms - moves chromos (duplicated) to middle of cell
53
- metaphase II
chromos aligned as in mitosis - microtubles attached to sister chromatids
54
- anaphase II
sister chromatids toward opposite poles - split at centromere
55
- telophase II
nuclei @ cell poles - cytokinesis occurs 2 same time = 4 haploid daughters total - single chromos
56
- meiosis yield
4 genetically unique haploid daughter cells
57
- where do all events unique to meiosis occur
meiosis I
58
- meiosis II difference to mitosis
meiosis II yield haploid daughters
59
- what is independent assortment of chromos + importance
2 equally probable arrangements ie red red / blue blue OR red blue / redd blue
60
- do all chromos independently orient
yes
61
- explain total # of chromo combos + eg
2^n (n=haploid number) ie humans n=23 so 2^23 = 8 million
62
- where does crossing over occur
chiasma (@ the tips)
63
- homologous chromos (homo chromatids (NOT sister tids)) remain attached at chiasmata until when
anaphase I
64
- purpose of crossing over
without there would only be 2 types of gametes - instead they are RECOMBINANT -from genetic recombination
65
- can a single crossover event affect many genes
yes
66
- where does meiosis occur humans
testes/ovaries
67
- nondisjunction def
chromos fail to separate at anaphase I or II
68
- what happens when normal gamete fuse with extra chromo gamete
2n + 1 - mitosis transmits abnormality to all embryonic cells - will have abnormal karyotype
69
- explain downs syndrome
people with trisomy 21 - 3 #21 chromos
70
- how do mammalian sex chromos function normally
only one X chromo cuz other copies deactivated
71
- explain Klinefelter syndrome/Turner syndrome
klinefelter XXY - males - sterile + breast enlargement // turner XO O = nothing = web of skin from neck to shoulder
72
- what is a motivation for studying human genetics + examples
to map geens conferring to suceptibility of diseases - Human Genome project - now 1000 genomes project
73
- what to bioinformaticists do
combine computer knowlede with genetics
74
- what level does reproduction occur at
cellular level
75
- eukaryote DNA organization
in linear chromosomes
76
- explain advantage of multi-cellular organisms + eg
DIVISION of LABOUR ie liver cells just to process toxins - ie eucaryotes engulg procaryotes by endosymbiosis - these become mitochondira/chloroplasts
77
- explain gamete cell production
at some point cells put away - animals put away at specific time - plants no specific time = regrowth from clippings
78
- talk Weismann diagram of gametes
(Germ⋰Soma) → (Germ⋰Soma) → (Germ⋰Soma)
79
- what is germ line
cells that produce the gametes
80
- what is soma
body of cells - NOT reproductive cells
81
- Lamarck’s defunct idea about germline
inheritance of acquired characteristics - selection in soma could influnce germline - DEFUNCT
82
- what are stem cells
cells in early development - still have potential to produce different rogan cells
83
- gene and chomosome descriptions
genes are strings of ACGT nucleotides - produce polypeptide that affects phenotype // chromos are long chains of genes
84
- chromo locus + example
place where different alleles occur - ie sickle cell hemoglobin - allele 300 pairs long - one pair change = change in allele
85
- main purpose of sex/meiosis
to generate variation
86
- 2 things genetics focus on
explaining hereidty resemblance // how offspring slightly different than parents
87
- why/how dominant/recessive alleles important
somatic cells have 2 copies of each gene - so homozygous if 2 same copies - heterozygous if different - phenotype of heterozygous shows what allele is recessive
88
- example of PHENOTYPE determining RECESSIVE ALLELE
a Blonde woman with Blonde and brunette alleles - Bb - because she’s blond the b brunette is recessive
89
- name of cloned sheep
Dolly
90
- do all eukaryotes have sex? (gamete fusion) + eg
no ie diplomonads
91
- what is origin of all different alleles
mutation
92
- what do mates produce
F1 offspring - the originals
93
- what dominants would produced tall blonde F1
Tall & Blonde
94
- pupose of independent assortment in F1 mating
two F1s can produce offspring with recessive traits - T b / TB / t B/ tb can be t_b_ with t_b_ - mating and assortment produce new variation combos
95
- what happens to producing offspring with recessive traits if two genes on same chromo
F2s will not produce recessive ie short brunette - instead need RECOMBINATION - break up/switch to get t___b_
96
- what makes sex advantageous
sex with recombination of chromosomes = new allels that make adaptive combos ie “short brunette well suited to vancouver”
97
- percentage of organells duplicated during interphase
90%
98
- why are sister chromatids side by side
double strands of DNA coming off each centromere in both directions
99
- is interphase considered part of mitosis
no - prophase is beginning
100
- what beside spindle apparatus is made of microtubles
flagella and cilia
101
- Fact mitosis prophase POLES form
good
102
- Fact could also get short brunettes from mutation alone but crossing over much more efficient
!
103
- what pinches the membrane animals cytokinesis
contractile filaments
104
- Fact: new combinations of alleles attched together on duplicated chromosomes after mitosis
good
105
- 3 ways to generate variation besides mutation
meiosis I - homologous pairs of duplicated chroos cross over (ie to allow short brunette) // independent assortment anaphase I (not all from just mom/dad) // fusion of gametes - mix up genomes
106
- 2 pairs of chromos allow for how many types of gametes (then how many for 3)
4 types of gametes from 2 pairs // 8 from 3 pairs
107
- Fact: Data from contemporary populations shows high levels of excess mortality
despite halvving of interbirth intervals
108
- which chromo on the karyotype is the largest
the 1st
109
- explain HIV resistant gene
CCR5Δ32 - 32 base pairs forgot to get copied - 2 copies of the CCR5Δ32 gene = resistant to HIV infection - affects T cells - virus cant bind to cell receptor - viking hypothesis - vikings brought it along
110
- single cell prokaryotes chromos
- no nucleus - one circular chromosome - gene for making receptor membrane in all genes - so if bad gene = U die
111
- what is complete dominance
an allele that will always be expressed over recessive Allele
112
- what is homozygous recessive
all alleles for gene recessive in org
113
- what is incomplete dominance
blending of two phenotypes - ie red and white to pink
114
- what is co-dominance
express both equally ie AB
