Lecture 2 Genetics

Question 1

DNA

Answer 1

Deoxyribonucleic acid

Double helix composed of nucleotides and nitrogen bases

Question 2

Gene

Answer 2

Blueprint for producing protein

Question 3

Chromosome

Answer 3

46 in total (23 pairs)

Large unit of heredity composed of thousands of base pairs

Question 4

Autosomal

Answer 4

Chromosome that isn’t a sex chromosome (chromosome 1-22)

Question 5

Locus

Answer 5

Location of a gene in a chromosome

Question 6

Alleles

Answer 6

Matching pairs of genes the same trait in the same location in a pair of chromosomes

Question 7

Homozygote

Answer 7

A pair of alleles is identical

Question 8

Heterozygote

Answer 8

A pair of alleles is different

Question 9

Genotype

Answer 9

genetic pattern (Bb)

Question 10

Phenotype

Answer 10

Expression if gene (physical feature)

Question 11

Dominant

Answer 11

Will be seen if one copy is present

Question 12

Recessive

Answer 12

Manifiest if identical pair is present

Question 13

Carrier

Answer 13

Person with one recessive gene and trait isn’t expressed

Question 14

Genomics

Answer 14

Study of multiple genes and their interactions

Question 15

Pharmacogenomics

Answer 15

Study of how genes influence an individuals response to medications

Question 16

Penetrance

Answer 16

Ration of how many person with phenotype have genotype

Question 17

Expressivity

Answer 17

Disorder can be expressed more or less severely in different individuals

Question 18

Polygenic/ multi factorial disorders

Answer 18

Multiple imperfect genes stimulated by environmental factors expressing an undesirable treat

Question 19

Epigenetics

Answer 19

Study of heritable changes in gene expression that don’t involve DNA alterations

Question 20

Chromosome disorders

Answer 20

Changes in # or structure of chromosome

Question 21

Gene expression

Answer 21

Whether gene will be active or not

Question 22

Translocation

Answer 22

When one part of chromosome breaks off and connects to another chromosome

Question 23

Repression

Answer 23

Gene expression is decreased

Question 24

Mutations

Answer 24

Accidental errors in duplication or destruction of parts of genetic code

Question 25

Somatic mutations

Answer 25

Alterations in genetic code of body’s somatic cells

Question 26

Mosaic

Answer 26

Cells with different #s of chromosomes within the same individual

Question 27

Autosomal dominant inheritance

Answer 27

Single gene disorder when defective allele is dominant and overrides normal allele Signs and symptoms occur later on 50% chance of inheriting Ex: Huntington, neurofibromatosis, Marfan syndrome, familial hypercholesterolemia

Question 28

Huntington’s Disease

Answer 28

Defect on chromosome 4 causing CAG to repeat causing overproduction of “Huntington” chemical causing progressive brain damage

Question 29

Huntington disease side effects

Answer 29

``` Chorea (movement) Parkinsonism features Ridged Severe depression/sucidal thoughts common Meds used but no cure ```

Question 30

Neurofubromatosis (NF)

Answer 30

Autosomal dominant Rumors grow on nerves and decrease prod. of proteins “Elephant man syndrome”

Question 31

Marfan syndrome

Answer 31

Autosomal dom. Disorder Connective tissue disorder w/abnormalities in skeletal and cardiovascular systems Common in males Scoliosis, kyphosis, long arms, visual probs, pingeon chest, etc

Question 32

Familial hypercholesterolemia

Answer 32

Autosomal dom. Disorder Absent or dysfunctional LDL receptors by mutation of 19p gene locus Unable to remove LDL

Question 33

Autosomal recessive inheritance

Answer 33

``` Must have 2 copies of allele to be seen Children who have become carriers More prominent in children 25% chance of inheritance Ex: Phenylketonuria (PKU), Sickle cell, tay-Sachs, cystic fibrosis, thalassemia ```

Question 34

Phenylketonuria (PKU)

Answer 34

Autosomal recessive disorder Metabolic disorder-by elevated levels of phenylalanine (toxic to brain) Seizures, hyperactivity, dec. pigmentation, mental retardation in untreated infants

Question 35

Sickle cell disease

Answer 35

Autosomal recessive disorder Abnormal sickle cell shape in hemoglobin Ridgid Can cause blockage

Question 36

Tay-Sachs disease

Answer 36

Lysosomal enzyme, mutation on chromosome 15 Destroys nerve cells in brain+spinal cord Ganglioside accumulates Red spot on retina, weakened muscles, seizures, vision and head lung loss Fatal by age 5

Question 37

Cystic fibrosis

Answer 37

Autosomal recessive disorder Defects in CFTR gene Thick mucous secretion No cure and expected to learn 30-40

Question 38

Thalassemia

Answer 38

Genes good for Hogan formation are missing S&S: anemia, fatigue, weakness, SOB, No cure but symptomatic treatment is

Question 39

X-linked disorders

Answer 39

Defect on X chromosome Males can’t be carriers but will be expressed since they only have one X and 50% chance of prod. Affected male Females have 2 X chromosome but recessive traits are inhibited and 50% chance prod, female carrier

Question 40

X- disorders examples

Answer 40

Fragile x- syndrome Hemophilia A Dúchenme dystrophy Glucose - 6- phosphate dehydrogenase deficiency (G6PD)

Question 41

Fragile X Syndrome

Answer 41

Don’t make FMR1 gene (needed for normal brain development) | Autistic behavior, developmental delays makes have long face and large mandible

Question 42

Hemophilia

Answer 42

Deficiencies of clotting factors cause failure in prod. clots

Question 43

Duchenne Muscular Dystrophy (DMD)

Answer 43

Generic disorder characterized by progressive muscle degeneration and ness from mutation in dystrophin gene

Question 44

G6PD deficiency

Answer 44

``` X linked disorder that’s the Most common enzyme disorder that primary affects men. Causes hemolysis (break apart RBC) ```

Question 45

Disjunction

Answer 45

Separation of homologous chromosomes to prod. 2 daughter cells with 23 chromosomes

Question 46

Nondisjunction

Answer 46

Pair of chromosomes fails to separate resulting in abnormal distribution of chromosomes in daughter cells

Question 47

Down Syndrome

Answer 47

``` Trisomy 21 (extra chromosome) Flattened facial profile, small hand and feet, protruding tongue ```

Question 48

Nondisjunction of sex chromosomes

Answer 48

Can cause individuals to be born female with one X (Turner syndrome) or extra C (Klinefelter syndrome)

Question 49

Turner Syndrome

Answer 49

Female with one X | Extra fold of skin on neck, short stature, heart defects, low hairline, early loss of Carina function

Question 50

Klinefelter syndrome

Answer 50

Males have extra X chromosome | Lack testes development; skeletal/cardiovascular abnormalities, feminine distribution, tall and lanky

Question 51

Multi factorial/ polygenic disorders

Answer 51

Two or more genes or gene loci influence the expression of gene trait Environmental triggers are thought to be necessary for the trait to be expressed Ex: cleft lip and palate, TEV,

Question 52

Cleft lip and palate

Answer 52

Incomplete closure of the maxillary facial bones | Cleft palate occurs when the tissue that makes up the roof of the mouth is not joined together

Question 53

Congenital talipes equivocaría (TEV)

Answer 53

Club foot | Foot deformity that causes the bones and tendons of the IV to turn in word

Question 54

Teratogen

Answer 54

Substance that produces abnormalities during embryonic or fetal development

Question 55

Fetal Alcohol Syndrome (FAS)

Answer 55

Exposure to excess maternal alcohol consumption while in utero throughout the entire pregnancy Born with restarted physical growth, intellectual disability, cardiac defects, and musculoskeletal abnormalities Mental retardation

Question 56

Thalidamide

Answer 56

A teratogenic drug given to pregnant women for morning sickness relief Babies born with deformed missing limbs (phocomelia)