Genetics:

Question 1

Genetics & Genomics Definition:

Answer 1

Genetics: study of biologic hereditary

Genomics: field of genetics concerned w/ structural and functional studies of the genome

Question 2

Human Genome Project

Answer 2

Sequence and map the genome of our species 1990-2003

Notable for ethical, legal, social implications/Transparencies/legal designation of human genes as naturally occurring not subject to patent

Only found about 24,000 genes

Much of genome made up of DNA that doesn’t code for protein (noncoding sections act as switches to regulate when and where coding genes are activated)

Question 3

Pharmacogenomics:

Answer 3

uses individual’s genome to determine whether or not a therapy would work

Question 4

Precision Medicine:

Answer 4

Using someones genome as a roadmap for patients clinical care
Oncology especially

Question 5

Newborn Screening:

Answer 5

Every baby tested at birth for 29-50 severe, inherited, treatable genetic diseases
Whole genome would give enable clinicians to look for mutations

Question 6

First job of DNA in genome is?

Answer 6

Fetal Development

Once formed, DNA in genome is interpreted to make protein which direct somatic growth and homeostasis processess

Question 7

Where does protein synthesis occur?

Answer 7

Occurs in RNA Transcription phase which occurs in the nucleus

Question 8

Where does Translation occur?

Answer 8

occurs in cytoplasm and proteins are generated using mRNA as a template

tRNA brings corresponding amino acids to the protein chain

Binds 5’ end of mRNA chain

Moves along until encounters stop codon AUG

Question 9

What are chromosomes?

Answer 9

Units of DNA/histones called nucleosomes which winds together to form chromatin fiber
Somatic Cells- 46 chromosomes (23 pairs)
Gamete Cells- 23 chromosomes

Question 10

Chromosome markings:

Answer 10

Short arm= P
Long arm= Q
Centromere= attach chromatids
Telomere=region containing multiple base pairs

Question 11

What mutation is transmitted to offspring?

Answer 11

gametes

Question 12

Silent/Missense/Nonsense/Frameshift mutations:

Answer 12

-Silent: Doesn’t change amino acid sequence of a gene

-Missense: results in single amino acid change in translated gene product

-Nonsense: mRNA stop codon produces premature stop
or removes stop

-Frameshift: alteration of DNA addition or deletion of base pair occurs

Question 13

Gain of function:

Answer 13

Assoc. with dominant disorders
production of new proteins
over-expression of protein product

Question 14

Loss of function:

Answer 14

Assoc. with Recessive disorders
Loss of 50% of protein product
(may not be adequate for normal function)

Question 15

Single Gene Disorders (inherited):

Answer 15

Autosomal Dominant/Recessive and sex-linked

Question 16

Incomplete Dominance:

Answer 16

Trait inherited in a dominant manner but is less severe than expressed in parent

Question 17

Co-dominance:

Answer 17

Ability to detect expression of 2 alleles (mixed)

Question 18

Autosomal disorders:

Answer 18

Occurs as a result of mutation in genes with loci on chromosomes 1-22
Males/females equally affected
Equal transmission

Question 19

Autosomal Dominant Disorder:

Answer 19

Most common
Between unaffected homozygous parent and affected heterozygous parent (Aa)
Expressed equally
Gain of function
Ex: achondroplasia (over express chondrocytes-inhibit growth)
Age Dependent: Huntington’s disease/Familial cancers

Question 20

Autosomal Recessive Disorders:

Answer 20

Most common situation is union between two unaffected heterozygous parents
expressed equally in M/F
Loss of function
Ex: cystic fibrosis, sickle cell disease, tay-sach’s

Question 21

Sex Linked Disorders:

Answer 21

On X or Y chromosome
usually effects son
usually only given by mom

Question 22

X-linked Recessive Disorders:

Answer 22

Most common situation is union between an unaffected carrier female and affected male
examples: hemophilia, duschenne muscle dys, SCID, color blindness

Question 23

Penetrance

Answer 23

Probability that an individual will express a given phenotype given that individual possesses a predisposing genotype
all or none concept
may be influenced by environmental factors

Question 24

Reduced penetrance:

Answer 24

condition not manifested in all individuals with predisposing genotype