Lec 9 - Chromsomes

Question 1

describe normal functions of protein factors associated with chromatin
diseases such as ATR-X, ICF, RETT, and Rubinstein-Taybi syndromes.

Question 2

explain the key differences between facultative and constitutive
heterochromatin.

Question 3

epigenetic regulation and genetic regulation.

Question 4

describe the types of histone modifications and responsible enzymes.

Question 5

explain the histone modification state typical of euchromatin and
heterochromatin.

Question 6

discern heterochromatin from euchromatin on the basis of DNA
sequences, their modification state and replication timing

Question 7

describe marker proteins typical of heterochromatin and their functions.

Question 8

indicated that she had apparently normal development until 18 months and had
normal head circumference at birth. But between 3 months and 4 years, the rate of
head growth was noticeably decelerated, with severely impaired expressive
language, repetitive hand movements, shaking of the torso, and toe-walking. There
was no family history of her condition and cytogenetic analysis did not reveal any
apparent anomaly in chromosome morphology. Genetic examination revealed a
mutation in Methyl-CpG binding protein 2 (MeCP2) which is consistent with ______

Answer 8

Rett
Syndrome.

Question 9

Diseases associated with- and caused by defects in chromatin regulators

Answer 9

Neurodevelopmental and psychiatric disorders including autism spectrum
disorder (ASD), Schizophrenia, as well as many congenital anomalities
including neuronal and heart defects

Question 10

Distinguish nucleoids and nucleosomes.

Answer 10

Nucleoid =
nucleosome = DNA + 1 histone octomer

Question 11

what is the highest level of packing of genomic DNA

Answer 11

metaphase chromosomes

Question 12

centromere and telomere sequenses

Answer 12

centromeres - A+T rich 171 bp sequences called alpha satellite DNA

Human telomeres, 5-15 kb in size,
consist of hexameric TTAGGG repeats