Chromosomes, cell division, meiosis and chromsoome abnormalities Flashcards Preview

Principles of disease JK > Chromosomes, cell division, meiosis and chromsoome abnormalities > Flashcards

Flashcards in Chromosomes, cell division, meiosis and chromsoome abnormalities Deck (26)
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1
Q

Telomere

A

Protect ends and prevent erosion

2
Q

Centromere

A

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
Q

Kinetochore

A

Protein complex on centromere where microtubule attaches

4
Q

How to get over shortening chromosomes

A

Enzyme telomerase adds DNA using RNA as lose bases after every mitosis

5
Q

S phase

A

replication

6
Q

G1

A

Cell growth

7
Q

G2

A

Cell divide

8
Q

Interphase

A

G1, S , G2

9
Q

M phase

A

Prophase, metaphase, anaphase , telophase and cytokinesis

10
Q

Prophase

A

Spindle from centriole and nuclear membrane breakdown

11
Q

Metaphase

A

Chromosomes replicated and align on M plate where spindle attaches

12
Q

Anaphase

A

Sister chromosomes separate and move to opposite poles

13
Q

Telophase

A

Reform nuclear membrane

14
Q

Cytokinesis

A

Cytoplasm separates

15
Q

Nucleosome

A

Negative DNA and positive histone protein => solenoid

16
Q

Why package DNA?

A

DNA neutralised and takes up less space

Inaccessible until required

17
Q

Metacentric

A

Similar p and q length

18
Q

Submetacentric

A

Slightly offset

19
Q

Acrocentric

A

Q much larger than p and no coding DNA

20
Q

FISH

A

Look for specific area of interest in karyotype

Label with fluorescent dye

21
Q

What can FISH be used for

A

Centromeric - chromosome number

Telomeric, unique sequence or whole chromosome differences

22
Q

Meiosis

A

Diploid => haploid

Recombination occurs => genetic diversity

23
Q

Oogenesis

A

Egg formation 10-50 years

20-30 mitoses and 1 egg with 3 polar bodies

24
Q

Spermatogenesis

A

60-65 days so more chance of mutation

4 spermatids and 100-200 million per ejaculate

25
Q

Do mitochondria come from only mum or dad?

A

Mum

26
Q

What is a barr body?

A

X inactivation occurs in females and the barr body is the inactive x chromosome