Final Review

Question 1

What determines if you are male or female?

Answer 1

Presence of SRY gene

Question 2

If male doesn’t have sry gene then they develop as

Answer 2

Female

Question 3

What is the difference between post transcriptional modifications and post translational modifications

Answer 3

Post Transcriptional - g cap, poly A tail, splicing
Post Translational - phosphorylation, methylation, acetylation, proteolysis, glycosylation

Question 4

How do we initiate transcription

Answer 4

Attach to Promoter

Question 5

What is special about the promoter, what is found within it

Answer 5

Transcription factors bind to TATA box, CpG islands

Question 6

Difference between DNA methylation and histone

Answer 6

DNA methylation - decrease transcription
Histone Methylation - increases transcription

Question 7

polymorphism

Answer 7

DNA variation that is really common

Question 8

Penetrance vs Variable Expressivity

Answer 8

Penetrance - Proportion of individuals with a certain genotype that shows the expected phenotype
Variable Expressivity - Variable degree to which the genotype can be expressed in an individual

Question 9

X-
XXY-
XXX-
XYY-

Answer 9

X- turner syndrome
XXY- kinefelter syndrome
XXX- normal
XYY- normal

Question 10

Role of SRY gene in sex determination

Answer 10

Embryo develops testies, no SRY develops ovaries

Question 11

What are the 3 main types of inheritance of mitochondria and chloroplast DNA

Answer 11

Maternal organelles in offspring derived from the mother
Paternal from father
Biparental from either the mother or the father

Question 12

What is the difference between DZ and MZ twins

Answer 12

DZ - fraternal
MZ - identical

Question 13

How to do concordance rate?

Answer 13

36 MZ twins both with, 40 MZ twins half with, 336 MZ twins neither
36(36+40)=47%

Question 14

Hybrid Vigor

Answer 14

cross between two different true breeding homozygotes result in stronger phenotype

Question 15

Epigenetics

Answer 15

changes in expression in a gene of set of genes without a change in DNA sequence, changes are HERITABLE and stable, but are REVERSIBLE

Question 16

What are epigenetics’ two main processes

Answer 16

DNA methylation, chromosomal protein alteration

Question 17

Cytosine residues in DNA can be modified by the _____ addition of a _______ group

Answer 17

covalent, methylation

Question 18

Clusters of CpG sites in the genome are called?

Answer 18

CpG islands, they are often found in promoters that are unmethylated

Question 19

Effects of DNA methylation

Answer 19

attracts proteins that are involved in the repression of transcription
important for development
cause cancer mutations

Question 20

What is chromatin remodeling

Answer 20

changes in chromatin structure

Question 21

Acetyltion of histones modifies nucleosomes to make DNA more accessible results in ___________. Histones are demethylated nucleosomes that remain intact holding DNA compact results in ____________.

Answer 21

Increased transcription
Blocked transcription

Question 22

Euchromatin vs Heterochromatin

Answer 22

Euchromatin - diffuse and light; contains DNA that is transcribed into mRNA
Heterochromatin - condensed and dark; DNA not transcribed, heavy methyls

Question 23

Barr Bodies can be seen…

Answer 23

in interphase in human females (cheek cells)

Question 24

Xist

Answer 24

non-coding RNA on the X chromosome
major effector of the X-inactivation process.

Question 25

3 Things in X-Inactivation

Answer 25

early in development, random inactivation, result in clones (Ex: Calico Cat)

Question 26

DNA sequences regulate rate of transcription what are two examples of them

Answer 26

Promoters: directly in front of the gene Enhancers: farther away Both are DNA sequences

Question 27

What are the two examples of transcription factors. They must assemble on the chromosome before RNA polymerase can bind to promoter

Answer 27

General and regulatory

Question 28

_______ binds to the TATA box; then other transcription factors bind, forming a transcription complex

Answer 28

TFIID TF interacts with RNA polymerase

Question 29

Transcription factors regulate the rate of transcription

Answer 29

true

Question 30

Positive and negative regulator examples

Answer 30

positive - enhancers, gene is not normally transcribed activator binds to stimulate transcrption negative - silencers, gene is normally transcribed but binding of repressor prevents transcription

Question 31

Can multiple genes be regulated at the same time

Answer 31

yes

Question 32

Enzyme changes nucleotide sequences. RNA editing --> ________. They are NOT _________. Goes to specific locations and changes _____.

Answer 32

change mRNA, splicing, one

Question 33

miRNA this is post transcriptional

Answer 33

small regulatory of noncoding RNA important for gene expression

Question 34

RISC complex

Answer 34

uses the siRNA or miRNA as a template for recognizing complementary mRNA

Question 35

What are the three ways to regulate mRNA translation:

Answer 35

miRNA, 5' end if G cap is not present at mRNA translation, repressor proteins block translation directly

Question 36

Protein Modifications: Proteolysis, glycosylation, phosphorylation

Answer 36

Proteolysis - cleaving by proteases Glycosylation - addition of sugars to form glycoproteins Phosphorylation - addition of phosphate groups by kinases

Question 37

How do CDKs get actively degraded

Answer 37

they are tagged with ubiquitin which binds to proteasome complex and are digested

Question 38

Promoter gene expression depends on...

Answer 38

promoter, enhancers and multiple transcription factors

Question 39

What is the most efficient way to regulate gene expression

Answer 39

mRNA transcription

Question 40

a clustor of gene with a single promoter is an ______

Answer 40

operon

Question 41

An operon consists of

Answer 41

a promotor, two or more protein coding genes, an operator (operator binds to a repressor protein which blocks transcription

Question 42

Lac Operon is always off or on?

Answer 42

OFF it is inducable (need receptor to turn on)

Question 43

How does lac work?

Answer 43

Lactose trigger on, binds to repressor, chhanges shape, falls off, translation ocurs

Question 44

Mutation in LacI would always be ___ because repressor won't be able to be made

Answer 44

off

Question 45

Operator is mutated in LacI would cause it to be ___

Answer 45

ON, because it is only when the promoter is mutated that the LacI is off

Question 46

The repressor protein has two binding sites:

Answer 46

one for operator one for inducer

Question 47

Inducer:

Answer 47

compound that inhibits gene expression by inhibiting a repressor

Question 48

Activator:

Answer 48

Binds DNA directly to influence RNA polymerase

Question 49

If the inducer is absent operon is ___

Answer 49

off, when bound it is on and the inducer binds changing the shape of the repressor

Question 50

_______ binding next to the lac operon promoter activates the operon

Answer 50

CRP-cAMP