Flashcards in Chromosomes, cell division, meiosis and chromsoome abnormalities Deck (26)
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1
Telomere
Protect ends and prevent erosion
2
Centromere
Join sister chromosomes which are held together with cohesins until anaphase
Site of kinetochore and non coding satellite DNA
Repeats 5' - TTAGGG-3' (10-15kb)
3
Kinetochore
Protein complex on centromere where microtubule attaches
4
How to get over shortening chromosomes
Enzyme telomerase adds DNA using RNA as lose bases after every mitosis
5
S phase
replication
6
G1
Cell growth
7
G2
Cell divide
8
Interphase
G1, S , G2
9
M phase
Prophase, metaphase, anaphase , telophase and cytokinesis
10
Prophase
Spindle from centriole and nuclear membrane breakdown
11
Metaphase
Chromosomes replicated and align on M plate where spindle attaches
12
Anaphase
Sister chromosomes separate and move to opposite poles
13
Telophase
Reform nuclear membrane
14
Cytokinesis
Cytoplasm separates
15
Nucleosome
Negative DNA and positive histone protein => solenoid
16
Why package DNA?
DNA neutralised and takes up less space
Inaccessible until required
17
Metacentric
Similar p and q length
18
Submetacentric
Slightly offset
19
Acrocentric
Q much larger than p and no coding DNA
20
FISH
Look for specific area of interest in karyotype
Label with fluorescent dye
21
What can FISH be used for
Centromeric - chromosome number
Telomeric, unique sequence or whole chromosome differences
22
Meiosis
Diploid => haploid
Recombination occurs => genetic diversity
23
Oogenesis
Egg formation 10-50 years
20-30 mitoses and 1 egg with 3 polar bodies
24
Spermatogenesis
60-65 days so more chance of mutation
4 spermatids and 100-200 million per ejaculate
25
Do mitochondria come from only mum or dad?
Mum
26
