Chapter 18

Question 1

Apply, interpret pedigree

Answer 1

Pedigree: Family tree that shows inheritance patterns over several generations

Look at the tree and see any affected and carrier

Question 2

CC recessive and dominant disorders

Answer 2

Autosomal Recessive Disorder

1. Need 2 mutated genes from each parent
2. Aa - heterozygous advantage/carrier
3. Homozygous recessive
   - aa - disease

Autosomal Dominant Disorder
1. Dominant causes the disease

Example: Polydactyly (P)
Pp x pp = 50% Infected

Question 3

CC, HD different types of disorders

Answer 3

changes to chromosome number (Aneuploidy: Extra or missing)

Due to Nondisjunction (Meiosis 1/2)
Monosomy: 2n-1 = missing 1 of a pair
Disomy: Typical state
Trisomy: 2n+1 = 3 chromosome (Ex: Trisomy 21 = down syndrome)

Aneuploidy of Sex Chromosomes (X0, XXY, and XYY)
Turner Syndrome: X0
Klinefelter Syndrome: XXY and XYY (Super Male)

changes to chromosome structure

Due to errors in Meiosis
1. Deletion (Missing)
2. Duplication
3. Inversion (Segment backwards)
4. Translocation (Segment moved)

genomic imprinting

Occurs during gamete formation
1. Often involves DNA methylation
2. 1 Allele silence and 1 expressed

Question 4

SEQ, CC genetic tests

Answer 4

Earlier test = better chance of prevention

1. Fetal Testing (Test done before birth)
   Ex: CVS and amniocentesis
2. Newborn Screening (Test done at birth)
   Ex: Metabolic disorder