LECTURE IX

Question 1

50% of genes in common

parents, dizygotic, or siblings and children

Answer 1

first degree relatives

Question 2

25% of genes in common

grandparents, aunts, uncles, nephews, nieces, and grandchildren

Answer 2

second degree relatives

Question 3

12.5% of genes in common

great grandparents, great grand children, first cousin

Answer 3

third degree relatives

Question 4

100% of genes in common

Answer 4

monozygotic twins

Question 5

a trait whose expression varies gradually between extremes

Answer 5

continuous trait

Question 6

a feature which at one extreme of expression manifests as a disorder

Answer 6

quasi continuous trait

Question 7

height, weight, intelligence, total ridge count, RBCs, blood pressure, skin colour

are examples of continuous or quasi continuous trait?

Answer 7

continuous trait

Question 8

sex influenced trait 2:1 M:F
both genetic and environmental etiology
bilateral in 50% of cases
often the orthopedic deformities or neurologic defects

Answer 8

talipes equinovarus or club foot

Question 9

trisomy 21 is what disease?

Answer 9

Down syndrome phenotype

Question 10

45XO is what disease?

Answer 10

Turner syndrome phenotype female

Question 11

5p (del) is what syndrome?

Answer 11

Cri-du-chat syndrome

Question 12

what are the types of chromosomal abnormalities?

Answer 12

constitutional vs acquired

homogenous vs mosaic

numerical vs structural

Question 13

what type of chromosomal abnormalities is this:

all cells have it from the time point zero

Answer 13

constitutional

Question 14

what type of chromosomal abnormalities is this:

some cells have the chromosomal abnormality and so once this carries over to organ development it carries on in that lineage of cells

Answer 14

acquired

Question 15

what type of chromosomal abnormalities is this:

karyotyped cells have this chromosomal abnormality

Answer 15

homogenous

Question 16

what type of chromosomal abnormalities is this:

only a portion of chromosome have triploid vs normal diploid of chromosomes

Answer 16

mosaic

Question 17

what type of chromosomal abnormalities is this:

unbalanced chromosomal abnormality

Answer 17

numerical

Question 18

what type of chromosomal abnormalities is this:

more or less than that amount

Answer 18

structural

Question 19

what type of rearrangement is this?

individual still has full complement in cells

may not be abnormal phenotype in individual

often identified in offspring

Answer 19

balanced rearrangements-balanced carrier

Question 20

what type of rearrangement is this?

phenotype likely to be abnormal due to a deletion or duplication

often produces abnormal fetus

duplications are comparable to a partial trisomy so,

deletion to a partial monosomy

Answer 20

unbalanced rearrangements

Question 21

name this type of structural abnormality?

involves the exchange of segments from two nonhomologous chromosomes

Answer 21

non homologous reciprocal translocations

Question 22

name this type of structural abnormality?

occur when part of a chromosome is missing, a part of a chromosome is extra, or a part has switched places with another part

Answer 22

deletions

Question 23

name this type of structural abnormality?

if the chromosome splits transversely rather than longitudinal

Answer 23

isochromosomes

Question 24

name this type of structural abnormality?

this can happen across the centromere or within the same arm, name two specific types

Answer 24

pericentric and paracentric inversions

Question 25

name this type of structural abnormality?

a major mechanism through which new genetic material is generated during molecular evolution. … Common sources of gene duplications include ectopic recombination, retrotransposition event, aneuploidy, polyploidy, and replication slippage.

Answer 25

duplication

Question 26

name this type of structural abnormality?

an aberrant chromosome whose ends have fused together to form a ring.

Answer 26

ring formation