Chromosomes and Cell Division Flashcards Preview

Principles of Disease HQ > Chromosomes and Cell Division > Flashcards

Flashcards in Chromosomes and Cell Division Deck (15)
Loading flashcards...
1

What is a telomere?

DNA at the end of the chromosome, solution to the end replication problem

2

What is the end replication problem?

Telomeres get shorter through generations
Eroded DNA part is added back on to the telomere using RNA template

3

What is a centromere?

Repeated satellite DNA around the centre of a chromosome
Location of kinetochore

4

What is the function of the kinetochore?

Protein complex that forms tubules for spindle attachment via microtubules

5

What occurs during the S stage of interphase?

DNA replication

6

What occurs during the G1 stage of interphase?

Cell growth

7

What occurs during the G2 stage of interphase?

Cell preparing to divide

8

Give two types of extragenic DNA

Satellite DNA
Minsatellite DNA

(repeat after a different number of base pairs)

9

What is a histone?

A protein that that DNA wraps itself around to form a chromatin fibre

10

What is a nucleosome?

A solenoid structure formed when histone/DNA complexes are further packaged

11

Give the three types of chromosome structure in terms of p arm and p arm lengths

Metacentric - p=q; central centromere
Submetacentric - p

12

Describe how a karyotype is obtained?

- blood sample removed of RBCs
- culture medium added
- incubation
- colchioine added (pauses mitosis via microtubule inhibition)
- WBCs removed
- hypotonic saline added
- spread/fix/photograph

13

What is FISH?

Fluorescent in situ hybridation
To look at chromosome sequence using different probes

14

Name three types of FISH probes

Centromeric - chromosome number

Telomeric - subtelomeric rearrangements

Whole Chromosome - dyes to highlight repeated sequences

15

Describe X-inactivation in female mammals

One X strand is randomly inactivated in the uterus

Prevents expression of double X characteristics