Genetics Exam 4 (Final)

Question 1

What is Chromatin?

Answer 1

Eukaryotic DNA combines with histone and non-histone proteins to from chromatin

Question 2

What is Nucleosomes

Answer 2

DNA wound on histones

Question 3

What does Chromatin structure do?

Answer 3

permits or inhibits transcription, replication and DNA repair

Question 4

What is Epigenetics?

Answer 4

heritable changes in gene expression that does not involve changes to the DNA sequence

Question 5

What does acetylation of histones do?

Answer 5

allows DNA to be more accessible

Question 6

what does DNA methylation do?

Answer 6

DNA methylation of cytosine bases adjacent to guanine nucleotides- CpG islands

Question 7

what are examples of epigenators?

Answer 7

nicotine, stress, infection, carcinogens, inflammation

Question 8

what are some maintainers

Answer 8

DNA methylases
Histone acetylases
Histone deacetylases

Question 9

How does epigenetics work?

Answer 9

a epigenator reaches a receptor, which through signal transduction reaches an initiator which either opens or closes genes

Question 10

Open v closed genes

Answer 10

open- DNA is unmethylated and histones are acetylated, genes can be transcribed

closed- DNA is methylated and histones are (not?) acetylated
genes cannot be transcribed

Question 11

What is a Barr Body

Answer 11

unactivated X chromosome

Question 12

What is that one equation?

Answer 12

1=p^2 + 2pq + q^2

p^2= homozygous dominant allele pair freq
q^2= homozygous recessive allele pair freq