Human Genetics 1

Question 1

How has medicine shifted in the past thirty years?

Answer 1

The chief cause of death has gone from infectious diseases to chronic constitutional or hereditary diseases

Question 2

What is cytogenetics?

Answer 2

Study of chromosome structure and identification of microscopically visible abnormalities

Question 3

What is molecular genetics?

Answer 3

The study of the structure and function of genes

Question 4

What is biochemical genetics?

Answer 4

How genetic defects disrupt normal metabolism/cell control mechanisms

Question 5

What is population genetics?

Answer 5

The study of how allele frequencies change in a population.

Question 6

What is clinical genetics?

Answer 6

Diagnosis/detection of inherited disorders; treatment; risk assessment; genetic counseling; and pharmacogenomics

Question 7

What is Pharmacogenmoics?

Answer 7

The study of the role of inherited and acquired genetic variation in drug response

Question 8

What is the Law of segregation?

Answer 8

Each individual possesses two genes for a particular characteristic, only one of which can be transmitted at any one time

Only deals with one trait

Question 9

What codominance?

Answer 9

alleles are expressed independently of the presence of each other

E.g. A and B alleles in blood

Question 10

What is the law of independent assortment?

Answer 10

Members of different pairs of alleles are assorted independently into gametes, and subsequent pairing of male and female gametes is random.

Talks about two or more traits

Question 11

What are the five exceptions to the law of independent assortment?

Answer 11

Epistasis

Linkage

Genomic imprinting

Mitochondrial Inheritance

Germline mosaicism

Question 12

What is epistasis?

Answer 12

The situation in which one gene masks the expression of another.

E.g. blue eyes

Question 13

What is Gene linkage?

Answer 13

The greater association in inheritance of two or more nonallelic genes than is to be expected from independent assortment

Question 14

What is genomic imprinting?

Answer 14

the phenomenon whereby the degree to which a gene expresses itself depends upon the parent transmitting it

Question 15

What is mitochondrial inheritance?

Answer 15

The inheritance of a trait encoded in the mitochondrial genome

Question 16

What is germinal mosaicism?

Answer 16

when an individual is composed of two or more cell lines in their germ cell population, where these cell lines are of different genetic or chromosomal constitution

Question 17

What are the four main types of genetic diseases?

Answer 17

Single-gene disorders

Chromosome disorders

Multifactorial disorders

Somatic cell genetic defects

Question 18

Describe Single gene defects

Answer 18

Stem from polymorphisms or mutations in one gene, have modes of inheritance.

E.g. cystic fibrosis, sickle cell

Rare, affect 2% of the population sometime during lifetime

Question 19

Describe chromosome disorders

Answer 19

Defect is dues to an excess or deficiency of the genes contained in whole chromosomes or chromosome segments.

E.g. Down or Patau syndrome

Question 20

Describe multifactorial inheritance disorders

Answer 20

inheritance by a combination of genetic factors and in some cases also non-genetic factors, each with only a relatively small effect.

E.g. Alzheimer, COPD, diabetes

Recur within families but they do not show any particular pedigree pattern