Introduction to Molecular Regulation and Signaling

Question 1

Embryonic development is directed by _______ that contain all of the information required to make an individual.

Answer 1

genomes

Question 2

The information in encoded in DNA in sequences that code for proteins

Answer 2

genes

Question 3

There are approximately how many genes in the human genome?

Answer 3

23,000

Question 4

What are the several levels gene expression can be regulated?

Answer 4

1) Different genes may be transcribed
2) DNA transcribed from a gene may be selectively processed to regulate which RNAs reach the cytoplasm to become messenger RNAs (mRNAs)
3) mRNAs maybe be selectively translated
4) proteins made from mRNAs may be differentially modified

Question 5

proteins (mostly histones)

Answer 5

chromatin

Question 6

basic unit of structure of genes

Answer 6

nucleosome

Question 7

What is each nucleosome composed of

Answer 7

an octamer of histone proteins and approximately 140 base pairs of DNA

Question 8

Nucleosomes themselves are joined into clusters by binding of DNA existing between nucleosomes (_______) with other histone proteins(_______)

Answer 8

Linker DNA and H1histones

Question 9

Chromatin appears as beads of nucleosomes on a string of DNA when the nucleosome is inactive

Answer 9

Heterochromatin

Question 10

In the uncoiled state, chromatin is referred to as

Answer 10

euchromatin

Question 11

Genes reside within the DNA strand and contain regions which can be translated into proteins

Answer 11

exons

Question 12

What is interspersed between exons and not transcribed into proteins?

Answer 12

introns

Question 13

What is interspersed between exons and not transcribed into proteins?

Answer 13

introns

Question 14

A typical gene includes:

Answer 14

A promoter region that binds RNA polymerase for the initiation of transcription; a transcription initiation site; a translation initiation site to designate the first amino acid in the protein; translation termination codon; and a 3’ untranslated region

Question 15

What is the site called for the promoter region, where the RNA polymerase binds, usually contains the sequence TATA?

Answer 15

TATA box

Question 16

regulatory elements of DNA that activate utilization of promoters to control their efficiency and the rate of transcription from the promoter

Answer 16

Enhancers

Question 17

can reside anywhere along the DNA strand and do not have to reside close to a promoter.

Answer 17

Enhancers

Question 18

Sometimes enhancers can inhibit transcription and are called

Answer 18

silencers