Chromosome Structure

Question 1

Types of Chromatin?

Answer 1

Heterochromatin (condensed)
Euchromatin (open)

Question 2

Arms of a chromosome?

Answer 2

q is long
p is short

Question 3

Wheres heterochromatin found in a chromosome?

Answer 3

Around centromere & telomeres

Question 4

Why package DNA?

Answer 4

• Condenses it
• neutralises -ve DNA with +ve histones

Question 5

Kinetochore?

Answer 5

Part of centromere that binds to spindle fibre microtubules
Protein complex

Question 6

How does hte lagging strand replicate DNA?

Answer 6

• DNA replicated in bits called okazaki fragments
• Each fragment started by a RNA primer
• End of replication each primer converted to DNA & fragments combined by DNA ligase

Question 7

Why do telomers shortedn during DNA replciaiton?

Answer 7

Because last RNA primer cant be converted to DNA so is lost

Question 8

Whats telomere shortening associated with?

Answer 8

Aging related diseases

Question 9

How could we counteract aging?

Answer 9

Sufficient concentrations of telomerase could counteract telomere shortening effectively immortalising cells

Question 10

What are the 4 phases of cell division?

Answer 10

G1
S
G2
Mitosis

Question 11

What occurs during the G1 phase?

Answer 11

Cell grows
Prepares precurosrs of DNA synthesis

Question 12

What occurs during S phase?

Answer 12

DNA replication

Question 13

What happens during G2?

Answer 13

Cell Growth
Prep for mitosis

Question 14

What are the phases of mitosis?

Answer 14

Prophase
Metaphase
Anaphase
Telophase
Cytokinesis

Question 15

What happens in prophase?

Answer 15

• Chormosomes condense
• Nuclear membrane dissapears
• Spindle fibres from centrioles

Question 16

What happens in metaphase?

Answer 16

• Chromosmes align at equator
• Spindle fibres attach to kinetochore of centromer by microtubules

Question 17

What happens in Anaphase?

Answer 17

• Sister chromatids seperate
• Move to opposite ends of cell

Question 18

Telophase?

Answer 18

2 new diploid nuclei form

Question 19

Cytokinesis?

Answer 19

Typically starts mid telophase
Cytoplasm seperates