W1: Molecular Genetics

Question 1

Create a sentence with word bank below:

Histone, DNA, acetylation, HAT, HDAC

Answer 1

When histone undergoes acetylation by HAT, DNA is more accessible (expression increased). HDAC does the opposite (deacetylase).

HAT - histone acetyltransferase
HDAC - histone deacetylase

Question 2

__ recognize DNA elements in promoters and/or enhancers

Answer 2

TF

Question 3

State function of each:

RNA Polymerase I, II, III

Answer 3

I - synthesis of most rRNAs

II - synthesis of mRNA
(“M” middle, II in between I and III)

III - synthesis of 5S rRNA and all tRNA
(“T” for three)

Question 4

Two functional regions of TF are:

Answer 4

DNA binding domain, activator/repressor domain

Question 5

Function of miRNA is to ___.

Answer 5

Control gene expression (inhibition of post-transcriptional activity by binding; important in development)

Question 6

Histones are +/- charged, neutralizing the +/- charged DNA backbone.

Answer 6

+,-

Question 7

HDAC deregulation in seen in __ cells.

Answer 7

cancer

Question 8

HDAC silences/activates DNA transcription.

Answer 8

Silence

Question 9

DNA is usually methylated at __ base.

Answer 9

cytosine

Question 10

___ ___ are DNA regions with high frequency of CG repeats, usually methylated at the __ nucleotide.

Answer 10

CpG islands, C

Question 11

Methylation means activation/inhibition.

Answer 11

inhibition (silence)

Question 12

CpG islands are highly methylated repeat CpG sequences usually found in ___ regions.

Answer 12

Promoter (regulatory)

methylation provides stability

Question 13

CpG dinucleotides (CG sites) are methylated by ___.

Answer 13

DNMT (DNA methyltransferase)

Question 14

___ is a DNA repair protein on guanine nucleotide.

Answer 14

MGMT - methylguanine-DNA methyltransferase

Question 15

If MGMT promoter is methylated, gene will be ___, allowing damage to occur.

Answer 15

silenced

MGMT - methylguanine-DNA methyltransferase; a DNA repair protein

Question 16

DNA methylation occurs on ___ residue of CG nucleotides (aka __).

Answer 16

Cytosine, CpG

Question 17

Transcriptional repression of DNA methylation is mediated by ___.

Answer 17

MBD (methyl-CpG-binding domain)

Question 18

Epigenetic drugs include demethylating and HDAC inhibitors. What are their effects on DNA?

Answer 18

Demethylation - activate

HDAC inhibit - activate

Question 19

Default developmental pathway is M/F unless the ___ gene is present.

Answer 19

Female, SRY

Question 20

Female meiosis beings in ___ as a ___.

Answer 20

Utero, fetus

Question 21

Male meiosis begins at ___ and continues throughout adult life.

Answer 21

puberty

Question 22

Many oocytes in the female fetus undergo meiosis I by ___ of fetal life.

Answer 22

The end of 1st trimester

Question 23

By birth, all oocytes have reached ___ _ of meiosis and are primary/secondary oocytes.

Answer 23

Prophase I, primary

Question 24

Primary oocytes remain in meiotic arrest at __ _ for decades until puberty.

Answer 24

Prophase I

Question 25

In females, meiosis II is initiated and proceeds to ___ _ during ___.

Answer 25

Metaphase II, ovulation

Question 26

In the female body, meiosis II is complete when ___ occurs

Answer 26

Fertilization

Question 27

Differentiation of gonads occur in __ week of gestation.

Answer 27

week 6

Question 28

By birth, all oocytes are at meiotic arrest at ___ of meiosis I/II.

Answer 28

Prophase, I.

Question 29

In females, meiosis I/II is completed when follicles mature prior to ovulation.

Answer 29

I

Question 30

During ovulation, meiosis I/II is initiated and come to a second meiotic arrest at ___.

Answer 30

II, metaphase

Question 31

First meiotic arrest: ___ I (released when follicles mature)

Second meiotic arrest: ___ II (released when ovum is fertilized)

Answer 31

Prophase

Metaphase

Question 32

Meiosis I/II is when diploid number is reduced to haploid.

Answer 32

I

Question 33

Crossover occurs during ___ _.

Answer 33

Prophase I

Question 34

Nondisjunction in meiosis I or meiosis II results in different consequences:

in meiosis I the resulting aneuploid germ cell will have both parental chromosomes present/absent, whereas in meiosis II two copies of one parental chromosome will be ___.

Answer 34

present,

duplicated

Question 35

Location of fertilization: __

Answer 35

Fallopian tube

Question 36

Metaphase II arrest is released (meiosis carried to completion) when ___ happens.

Answer 36

fertilization

Question 37

___ are enzymes that regulate histone by removing ___ group to condense/decondense histone and promote/silence transcription.

Answer 37

HDAC (histone deacetylase), acetyl, condense, silence