genetics - exam 2

Question 1

phenotype

Answer 1

observable physical characteristics of an organism

Question 2

genotype

Answer 2

genetic makeup of an organism

Question 3

sex-linked

Answer 3

a gene located on a sex chromosome

Question 4

autosome

Answer 4

any chromosome other than a sex-linked chromosome

Question 5

agenesis

Answer 5

failure of an organ to develop

Question 6

atresia

Answer 6

failure of a normal body opening or tube to form

Question 7

example of atresia

Answer 7

trachea-esophageal atresia

Question 8

hypoplasia

Answer 8

smaller than normal organs

Question 9

examples of hypoplasia

Answer 9

fetal alcohol syndrome, mental retardation, indistinct philtrum, maxillary hypoplasia

Question 10

ectopia

Answer 10

abnormal location of an organ or tissue

Question 12

examples of ectopia

Answer 12

ectopia cordis + cryptorchidism

Question 13

syndactyly

Answer 13

fingers fused together, failure of apoptosis to occur

Question 14

common teratogens that cause developmental defects

Answer 14

alcohol, thalidomide, diethyl stillbestrol, TORCH infection, treponema

Question 15

developmental defects alcohol causes

Answer 15

mental retardation

Question 16

developmental defects thalidomide causes

Answer 16

phocomelia

Question 17

developmental defects di-ethyl stillbestrol causes

Answer 17

vaginal adenocarcinoma

Question 18

developmental defects TORCH infections cause

Answer 18

brain infections, heart defects, cataracts, deafness

Question 19

developmental defects treponema causes

Answer 19

blindness + deafness

Question 20

3 modes of inheritance of genetic disorders

Answer 20

autosomal, sex-linked, polygenic inheritance

Question 21

autosomal disorder

Answer 21

mutations of genes located on any chromosome except sex chromosomes

Question 22

what is the chance of inheriting an autosomal dominant disorder

Answer 22

50% if 1 parent has the gene

Question 23

what is the chance of inheriting an autosomal recessive disorder

Answer 23

25% chance if both parents have the gene

Question 24

sex-linked disorders

Answer 24

disorder linked to sex chromosomes

Question 25

aneuploidy

Answer 25

abnormal number of chromosomes that is not a multiple of the normal haploid

Question 26

examples of aneuploidy

Answer 26

turner syndrome + down syndrome

Question 27

polyploidy

Answer 27

chromosome is 2x or more than the normal haploid number

Question 28

deletion chromosomal disorder

Answer 28

loss of a portion of a chromosome

Question 29

translocation chromosomal disorder

Answer 29

segment of one chromosome is transferred to another chromosome after both chromosomes are broken

Question 30

point mutations chromosomal disorders

Answer 30

change in a single nucleotide

Question 31

frameshift mutation chromosomal disorder

Answer 31

base pair insertions/deletions that change the codon reading frames

Question 32

what is an example of a DNA point mutation

Answer 32

sickle cell disease + hereditary hemochromatosis

Question 33

what is an example of a frame shift mutation

Answer 33

tay sachs disease + cystic fibrosis

Question 34

down syndrome chromosome abnormality

Answer 34

extra copy of chromosome 21

Question 35

down syndrome physical features

Answer 35

monogoid facies, epicanthic folds, transverse palmar crease, longitudinale crease

Question 36

klinefelter syndrome chromosome abnormality

Answer 36

2 x chromosomes + 1 y chromosme

Question 37

klinefelter syndrome physical features

Answer 37

tall, thin, no facial hair, some breast tissue, less developed testes

Question 38

turner syndrome chromosomal abnormality

Answer 38

only 1 sex chromosome (x)

Question 39

turner syndrome physical features

Answer 39

short stature, web neck, widely spaced nipples, underdeveloped breasts

Question 40

what are 3 examples of sex-linked recessive disorders

Answer 40

duchenne muscular dystrophy, hemophilia A/B, lesch-nyhan syndrome

Question 41

an absence of what defective protein leads to a condition with progressive weakness? what is the condition?

Answer 41

dystrophin, duchenne muscular dystrophy

Question 42

Hemarthrosis in hemophilia is due to a lack of which substance

Answer 42

factor VIII + IX

Question 43

What condition is related to a uric acid accumulation and may be associated with self-mutilation?

Answer 43

lesch-nyhan syndrome

Question 44

What is the only sex linked dominant disorder?

Answer 44

vitamin d-resistant rickets

Question 45

True or False. A child who has bow legs, bone pain and a developmental delay with walking should be supplemented with vitamin D.

Answer 45

false

Question 46

How does the sickle cell trait express itself in an otherwise asymptomatic individual?

Answer 46

scuba diving + high altitudes

Question 47

What is the pathogenesis in adult polycystic kidney disease?

Answer 47

failure of secretory + excretory parts of the developing kidney to connect

Question 48

Lens ectopia, arachnodactyly and blood vessel defects are features of which autosomal dominant disorder?

Answer 48

marfan's syndrome

Question 49

Which autosomal dominant condition is associated with increased elasticity of the skin, hypermobile joints and a predisposition to early onset joint degeneration?

Answer 49

ehlers-danlos syndrome

Question 50

What is the chromosomal structural abnormality associated with brittle bone disease?

Answer 50

defective collagen synthesis type 1

Question 51

Which category of autosomal recessive disorder does McArdle disease belong to?

Answer 51

glycogen storage disorders

Question 52

Accumulation of which substance leads to this disorder, and where is the accumulation occurring?

Answer 52

glycogen

Question 53

Thalassemia belongs to which category of autosomal recessive disorder

Answer 53

hemopoietic disorders

Question 54

Which lysosomal storage disease leads to an accumulation of gangliosides in the brain and spinal cord, and is associated with a poor prognosis?

Answer 54

tay-sachs disease

Question 55

An accumulation of what substance is seen in an autosomal recessive disorder characterized by ataxia, cirrhosis and splenomegaly? what is the disorder

Answer 55

sphingomyelin; niemann-pick disease

Question 56

In which autosomal recessive metabolic condition is a Guthrie test performed?

Answer 56

phenylketonuria

Question 57

Ochronosis seen in alkaptonuria is an accumulation of which substance?

Answer 57

homogentisic acid

Question 58

Which gene is defective in an autosomal recessive metabolic disorder associated with frequent sinus and lung infections, and steatorrhea?

Answer 58

cystic fibrosis

Question 59

True or False. Pyruvate Kinase deficiency is associated with hemolytic anemia.

Answer 59

true

Question 60

What are some clinical features seen with Sickle Cell Disease?

Answer 60

jaundice, anemia, fatigue, painful bone crisis, hepatosplenomegaly, priapism

Question 61

Which specific autosomal recessive hemopoietic disorder is associated with anemia that is hypochromic and microcytic, in a person of mediterranean descent?

Answer 61

thalassesmia

Question 62

Excessive absorption of which substance leads to low hepcidin in hereditary hemochromatosis?

Answer 62

iron

Question 63

Explain polygenic inheritance

Answer 63

small variations in many genes that add up + increase the risk

Question 64

examples of polygenic inheritance

Answer 64

hypertension, diabetes mellitus type 2, depression, schizophrenia