Genetic Lecture

Question 1

Excessively salty sweat is a symptom??

Answer 1

Cystic fibrosis

Question 2

Define genetics

Answer 2

Determined or influenced by gene(s)

Question 3

Define genetic disease

Answer 3

Disease or disorder that is inherited genetically

Question 4

What are major areas of genetics?

Answer 4

Transmission Genetics
Population genetics (polymorphism)
Quantitative genetics

Question 5

Define transmission genetics

Answer 5

Transfer of genetic information from gene to next generation

Question 6

Define population genetics

Answer 6

Genetic diversity at the individual, population and species level

Question 7

Define quantitative genetics

Answer 7

Genes results in distribution of phenotypic values

Question 8

Define penetrance

Answer 8

The percentage of individuals carry an autosomal dominant gene and expressing the trait

Question 9

Define variable expressivity

Answer 9

Variable expression of autosomal dominant trait in affected individuals

Question 10

Define genetic hetweogeneity

Answer 10

Production of a given trait by different mutations at multiple loci

Question 11

Define pleiotropism

Answer 11

Multiple end effects of a single mutant gene

Question 12

Define polymorphism

Answer 12

Multiple allelic form of a single gene

Question 13

What is gene regulation?

Answer 13

DNA –> pre-mRNA –> mRNA

Question 14

What is alternative gene splicing?

Answer 14

Gene –> gene product

• Single gene can create multiple proteins due to alternative splicing
• Gene consist of exons and introns, mRNA consists of exons
• From a single gene it can produce multiple forms of mRNA (it can transcribe multiple forms of mRNA due to alternative splicing)

Question 15

What is gene activation?

Answer 15

New synthesis, dissociation, modification, ligand binding

Question 16

What is gene inactivation?

Answer 16

Competition (change affinity or have excess of substrate, competitor competes with substrate)
Squelching
Quenching (decreasing activity or slowing down)
Direct

Question 17

What is microRNA?

Answer 17

Translational repression

Question 18

Define dicer

Answer 18

dices dsRNA to little RNA or miRNAs

Question 19

What is small interfering RNA?

Answer 19

target mRNA cleavage

Question 20

What is transacting siRNA?

Answer 20

mRNA cleavage

Question 21

What is small-scan RNA?

Answer 21

DNA elimination

Question 22

What is repeat-associated siRNA?

Answer 22

Transcriptional silencing

Question 23

What is Piwi-interacting RNA?

Answer 23

Transposon control in germ cells

Question 24

Define mutation

Answer 24

Permanent changes in the DNA
Uncoded or unprogrammed changes
Relatively rare, unusual changes

Question 25

Define germ cell mutations

Answer 25

Transmitted to the progeny | - Transmitted leads to hereditary diseases

Question 26

Define somatic cell mutations

Answer 26

No transmitted | - Leads to disease such as cancer, congenital, malformation

Question 27

Define genome mutations

Answer 27

Loss or gain of chromosomes usually lead to death

Question 28

Define chromosome mutations

Answer 28

Rearrangement of genetic material

Question 29

Define gene mutations

Answer 29

Partial or complete deletion of a gene or affect a single base

Question 30

How do cells undergo new mutations?

Answer 30

``` Mistakes during DNA copying Cell division (spontaneous mutations or environmentally caused mutations) ```

Question 31

Gene mutations occur?

Answer 31

Coding sequences | Non-coding sequence

Question 32

Mutations are affected by?

Answer 32

``` Addition Deletion Replacement Transposition Inversion ```

Question 33

Define Single Base Deletion

Answer 33

CAC to CAT change alters the reading frame (frame shift mutations) - Affects the AA sequence of glycosyltransferase genes

Question 34

Define point mutation

Answer 34

Single base pair change in the DNA alters the meaning of the genetic code, leading to replacement of flutamic acid by valine in the polypeptide chain - Beta thalassemia

Question 35

What causes beta thalassemia?

Answer 35

Caused by mutations in the HBB gene | - Inherited blood disorder that reduces the production of hemoglobin; without enough RBC cannot bind enough oxygen

Question 36

Define three-base deletion

Answer 36

Common cystic fibrosis allele results in synthesis of a protein that is missing amino acid 508 --> bc the deletion is a multiple of three, this is not a frameshift mutation

Question 37

Define Tay-Sachs

Answer 37

Lipid disorder in which significant accumulation of a fatty substance called ganliodises in the brain caused by insufficient activty of hexosaminidase A that catalyzes the biodegradation of gangliosides - For base insertion alters the reading frame , causing premature termination of protein synthesis

Question 38

Mutations in DNA leads to defects in?

Answer 38

Transcription Translation Post-translational processing Abnormal protein

Question 39

What defects cause abnormal protein synthesis to lead to loss of function?

Answer 39

``` Enzyme defects Accumulation of substrate Metabolic block Inactivation of corrosive substrates Defects in receptors and transport systems Alterations in key structural proteins Adverse reactions to the drugs Activation of protoncogenes Inactivation of tumor suppreser genes ```