Lecture 16

Question 1

What do chromatin, histones and nucleosomes consist of?

Answer 1

Chromatin: DNA and associated proteins
Histones: groups of highly conserver proteins
nucleosomes: repeating subunits of DNA and histones

Question 2

What are the different chromosome organization levels?

Answer 2

Lowest: Nucleosomes
higher: Chromatin loops

Question 3

What is altered to change the character of nucleosomes? Where does the modification take place?

Answer 3

Histone modification on the histone tails

Question 4

what is DNA wrapped around in nucleosomes?

Answer 4

a core complex comprised or histones

Question 5

What protein holds replicated DNA molecules together during mitosis & maintains DNA loops?

Answer 5

Cohesin

Question 6

what is the difference between Euchromatin, heterochromatin, Constitutive heterochromatin and Facultative heterochromatin?

Answer 6

Euchromatin: disperse state after mitosis

Heterochromatin: condensed during interphase

Constitutive heterochromatin: condensed all the time. frequent around centromeres and telomeres

Facultative heterochromatin: inactivated during certain phases, found in one of the X chromosomes to inactivate it