MENDELIAN GENETICS & INHERITANCE PATTERNS

Question 1

MENDEL’S LAW

Answer 1

Law of segregation
Law of independent assortment
Law of complete dominance

Question 2

unit of heredity

Answer 2

Gene

Question 3

different form of the same gene

Answer 3

Allele

Question 4

genes that have identical traits (TT)

Answer 4

Homozygous

Question 4

a trait that always appears

Answer 4

Dominant

Question 5

a variant that is masked by the presence of a dominant trait but reappears in subsequent generations

Answer 5

Recessive

Question 6

alleles that have different traits (Tt)

Answer 6

Heterozygous

Question 7

produced an offspring called the F1 generation (Filial generation).

Answer 7

Parental generation (P-generation)

Question 8

F1 self-fertilization producing

Answer 8

F2 (Filial 2 generation)

Question 9

The law of segregation predicts that the phenotypes of the F2 generation will be tall and dwarf in a ratio of?

Answer 9

3:1

Question 10

An easy way to predict the outcome of simple genetic crosses and self-fertilization experiments

Answer 10

Punnett Square

Question 11

Punnett square is originally proposed by ___________

Answer 11

Reginald Punnett

Question 12

Genotypes of a Punnett square

Answer 12

TT, (2) Tt, tt

Question 13

Two different genes randomly assort their alleles during the
formation of haploid cells.

Answer 13

LAW OF INDEPENDENT ASSORTMENT

Question 14

Genes of organism

Answer 14

Genotype

Question 15

Observable trait of organism

Answer 15

Phenotype

Question 16

The independent assortment has _________ ratio is the expected outcome when heterozygotes for two traits are allowed to self-fertilize.

Answer 16

9 : 3 : 3 : 1 ratio

Question 17

is a condition in which the
phenotype of a heterozygote is intermediate between the
corresponding homozygous individuals.

Answer 17

Incomplete dominance

Question 18

The phenomenon in which a heterozygote has greater reproductive success compared with either of the corresponding homozygotes is called

Answer 18

overdominance, or
heterozygote advantage.

Question 19

Defect in hemoglobin

Answer 19

Sickle anemia

Question 20

two alleles are both expressed in the heterozygous individual
is called

Answer 20

codominance

Question 21

relates the behavior of chromosomes to the Mendelian inheritance traits

Answer 21

CHROMOSOME THEORY OF INHERITANCE

Question 22

When studying human traits, however, researchers cannot control parental crosses. Instead, they must rely on the information contained within family trees, also called

Answer 22

Pedigrees/Pedigrees of Analysis

Question 23

Follow the well-known mendelian patterns of inheritance.

Answer 23

Single-gene defects (mutations)

Question 24

Mutations involving single genes follow one of three patterns of inheritance:

Answer 24

Autosomal dominant, Autosomal recessive, or X-linked.

Question 25

A single-gene mutation may have many phenotypic effects

Answer 25

Pleiotropy

Question 26

mutations at several genetic loci may produce the same trait

Answer 26

Genetic Heterogeneity

Question 27

Disorders of autosomal dominant inheritance are manifested in the heterozygous state, so at least one parent in an index case usually is affected.

Answer 27

Autosomal Dominant inheritance

Question 28

A ___ reduction in the normal gene product is associated with clinical signs and symptoms.

Answer 28

50%

Question 29

Proteins

Answer 29

membrane receptors, transport proteins, sturctural proteins

Question 30

An affected person has at least one affected parent An affected person has at least a ___ chance of passing the disorder to their children

Answer 30

50%

Question 31

Disorders of autosomal recessive inheritance are manifested in the homozygous state. They occur when both of the alleles at a given gene locus are mutants.

Answer 31

Autosomal Recessive inheritance

Question 32

IN Autosomal Recessive inheritance, In many cases, ______are affected by the mutation

Answer 32

enzymes

Question 33

Linked to mutations in genes on the X chromosome. The _____________ alleles can be dominant or recessive.

Answer 33

X-linked inheritance

Question 34

Heterozygous female carriers transmit them only to

Answer 34

sons

Question 35

An affected male does not transmit the disorder to sons, but

Answer 35

all daughters are carriers.

Question 36

is an autosomal dominant movement disorder associated with degeneration of the striatum (caudate and putamen).

Answer 36

HUNTINGTON’S DISEASE

Question 37

Pathogenesis of Huntington's disease

Answer 37

CAG trinucleotide repeat expansions in a gene located on 4p16.3 that encodes the protein huntingtin.

Question 38

Gene 4p16.3 code for the protein

Answer 38

Huntingtin

Question 39

Gene composition of Huntington's Disease

Answer 39

11-34 CAG

Question 40

CAG repeat expansion = more CAG =

Answer 40

Glutamine

Question 41

The HD is characterized by _______________ of all parts of the body

Answer 41

involuntary jerky movements

Question 42

_________________ movements of the extremities are typical. death after an average course of about 15 years

Answer 42

writhing movements

Question 43

The most common skeletal dysplasia and a major cause of dwarfism. autosomal dominant disorder resulting from retarded cartilage growth.

Answer 43

ACHONDROPLASIA

Question 44

The most common skeletal dysplasia and a major cause of___________.

Answer 44

dwarfism

Question 45

The most common skeletal dysplasia and a major cause of dwarfism. autosomal dominant disorder resulting from retarded

Answer 45

cartilage growth

Question 46

Defective gene of Achondroplasia

Answer 46

Fibroblast growth factor receptor 3 (FGFR3)

Question 47

inhibits bone growth

Answer 47

Fibroblast

Question 48

mutation results in a constitutively active receptor, thereby exaggerating this effect and suppressing growth.

Answer 48

Achondroplasia

Question 49

Shortened proximal extremities, a trunk of relatively normal length, and an enlarged head with bulging forehead and conspicuous depression of the root of the nose.

Answer 49

Achondroplasia

Question 50

is a “receptor disease” caused by loss-of-function mutations in the gene encoding the LDL receptor, which is involved in the transport and metabolism of cholesterol.

Answer 50

Familial hypercholesterolemia

Question 51

Familial hypercholesterolemia is a “receptor disease” caused by loss-of-function mutations in the gene encoding the _____________, which is involved in the transport and metabolism of cholesterol.

Answer 51

LDL receptor

Question 52

VLDL

Answer 52

ApoC, B-100, ApoE

Question 53

IDL

Answer 53

B-100, ApoE

Question 54

LDL

Answer 54

B-100

Question 55

FAMILIAL HYPERCHOLESTROLEMIA SYMPTOMS - twofold to threefold elevation of plasma cholesterol

Answer 55

Heterozygotes

Question 56

fivefold elevation

Answer 56

Homozygous

Question 57

Cholesterol deposits on skin and tendon sheaths

Answer 57

Xanthoma

Question 58

Formation of atherosclerosis resulting in coronary artery disease

Answer 58

HYPERTENSION

Question 59

Defects in the red cell membrane that lead to the formation of spherocytes, nondeformable cells that are highly vulnerable to sequestration and destruction in the spleen.

Answer 59

HEREDITARY SPHEROCYTOSIS

Question 60

PATHOGENESIS OF HERIDEITARY SPHEROCYTOSIS

Answer 60

Caused by inherited defects in the membrane skeleton, a network of proteins that stabilizes the lipid bilayer of the red cell.

Question 61

membrane skeleton a network of proteins that stabilizes the lipid bilayer of the red cell.

Answer 61

membrane skeleton

Question 62

major membrane skeleton protein.

Answer 62

Spectrin

Question 63

Mutations that cause hereditary spherocytosis most frequently involve____,_________,________

Answer 63

ankyrin, band 3, or spectrin.

Question 64

On smears, spherocytes are

Answer 64

dark red and lack central pallor.

Question 65

The characteristic features of Hereditary Spherocytosis are

Answer 65

anemia, splenomegaly, and jaundice.

Question 66

improves the anemia by removing the major site of red cell destruction.

Answer 66

Splenectomy

Question 67

Heme consists of a porphyrin ring coordinated with iron and is found mainly in hemoglobin.

Answer 67

PORPHYRIA

Question 68

Defects in the biosynthesis of heme result in a group of disorders known as

Answer 68

porphyrias