Genetics Exam 4 Review Part 1

Question 1

Gene Regulation

Answer 1

levels of gene expression under different conditions

Question 2

Constitutive Genes

Answer 2

unregulated genes that have constant levels of expression

Question 3

Gene Regulation Influences

Answer 3

• metabolism
• environmental stress
• cell division

Question 4

Regulatory Transcription Factors

Answer 4

influences transcriptional regulation

Question 5

Repressors

Answer 5

transcription factor that inhibit transcription (negative control)

Question 6

Activator

Answer 6

transcription factor that increase transcription (positive control)

Question 7

Inducers

Answer 7

1. bind to repressors and prevent them from binding to DNA
2. bind to activators causing them to bind to DNA

Question 8

Iac Operon

Answer 8

• Lactose
• consist of genes that control transcription
• consist of lacZ, lacY, lacA

Question 9

lacI gene

Answer 9

• has its own promoter
• codes lac repressors

Question 10

lac operon: repressor

Answer 10

regulated by repressor protein (coded by lacl gene)

Question 11

lac operon: inducer

Answer 11

• allolactose
• binds to repressor to prevent the repressor from preventing transcription
• allows transcription to occur

Question 12

Allolactose

Answer 12

Produced by B-galactosidase interacting with lactose

Question 13

lacl- (mutant)

Answer 13

• transcription/expression always occurs
• lacl doesnt make repressor protein due to inability to bind to proper sequence

Question 14

trans-effect

Answer 14

genetic regulation occurs with DNA segments not adjacent to one another

ex: lac operon/lac repressor

Question 15

cis-effect

Answer 15

genetic regulation occurs with adjacent DNA sequences

ex: lac operon

Question 16

Gene Expression

Answer 16

information within a gene is able to synthesize RNA and polypeptides (phenotype)

Question 17

Domains

Answer 17

Regions of transcription factor protein clumping

Question 18

Motif

Answer 18

small part of domain that has similar structure to other motifs

Question 19

Steroid Receptors

Answer 19

transcription factors that respond to steroid hormones… goal is to effect gene transcription

Question 20

Steroid Hormone Cycle

Answer 20

steroid hormone -> goes to endocrine gland -> secreted in blood stream -> taken by cells that respond to specific hormone

Question 21

Glucocorticoid

Answer 21

• promote glucose utilization/protein breakdown/fat mobilization

Question 22

How does the Steroid Glucocorticoid affect gene regulation?

Answer 22

1. binds to receptor units
2. enters nucleus
3. binds to GRE
4. activates gene expression

Question 23

CREB Protein

Answer 23

Activated by cAMP

Question 24

CREB Protein Cycle

Answer 24

2. activated by cAMP
3. Binds forming CBP
4. increases transcription of adjacent gene (controls rate of transcription)

Question 25

Non Coding RNA

Answer 25

- 7,000-10,000 in Human Body - more abundant than mRNA

Question 26

Crispr/Cas System

Answer 26

- defends against foreign invaders - utilizes non coding RNA -provides bacteria with defense against bacteriophages

Question 27

Exposure

Answer 27

baceriophages infects a bacteria cell

Question 28

Adaptation

Answer 28

1. Cas1/Cas2 form protein complex that cleaves bacteriophages 2. bacteriophages placed in crispr gene

Question 29

Expression

Answer 29

1. tracrRNA/pre-cRNA form a complex and cleaves cRNA 2. tracrRNA/cRNa bing to cas9 gene, which binds to bacteriophages DNA (complementary base pairing ) 3. bacteriophages is cleaved by cas9 gene preventing function

Question 30

Different Parts of Crisper/Cas System

Answer 30

Cas1/Cas2 - Complex tracrRNA/pre-cRNA tracrRNA/cRNA - complex tracrRNA/cRNA/cas9 - complex

Question 31

Crispr/Cas System and Targeting

Answer 31

cas9 is able to bind to bacteriophages because of its complementary base pairings at the spacer... cRNA helps cas9 find proper DNA sequence

Question 32

mutation

Answer 32

-heritable change in genetic material -more likely to be harmful - foundation for evolutionary change

Question 33

point mutation

Answer 33

change in a single base pair ( base substitution )

Question 34

point mutation: transition

Answer 34

change of base pair within pyrimidine or purine

Question 35

point mutation: transversion

Answer 35

change of base pair from pyrimidine to purine or vice versa

Question 36

Silent Mutations

Answer 36

do not alter amino acid sequence due to degrancry of genetic code

Question 37

missense mutation

Answer 37

alter amino acid sequence

Question 38

neutral missense mutation

Answer 38

alters amino acid sequence but has no effect on protein function

Question 39

nonsense mutation

Answer 39

base substitution that produces a stop codon

Question 40

frame shift mutation

Answer 40

addition or deletion of a number of nucleotides (that is not equal to three) shifting the reading frame