Chapter 6

Question 1

Genes

Answer 1

Units of heredity transmitted from one generation to another.
Genes are found on chromosomes

Question 2

Chromosomes

Answer 2

Long chains of molecules found in the cell nucleus, contains DNA
Each cell has 46 chromosomes (44 autosomes, 2 sex chromosomes)

Question 3

Alleles

Answer 3

Genes located at the same level in the two chromosomes of a pair, that determine the same function or characteristic

Question 4

Heterozygous

Answer 4

Two different genes at the allele level

Question 5

Homozygous

Answer 5

Identical genes at the allele level

Question 6

Dominant trait

Answer 6

Trait that shows clinically when it is carried by only one of a pair of homologous chromosomes (alleles)

Question 7

Recessive trait

Answer 7

Trait that shows clinically only if it has a “double dose” or is “homozygous” for the trait

Question 8

Trisomy 21 (Down syndrome)

Answer 8

Results from nondisjunction (chromosomes do not separate during meiosis)
30% have heart abnormalities
Extra autosome on 21st pair of chromosome
Fissured tongue, macroglossia, premature loss of teeth, hypodontia, periodontal disease, taurodont,
NO INCREASE RISK FOR CARRIES

Question 9

Turner’s syndrome

Answer 9

One extra autosome, 45 total chromosomes
Female phenotype with 44 autosomes and on,y one X chromosome (44XO)
Short, webbed neck, edema of hands and feet, aorta abnormalities
Underdeveloped ovaries and genitalia (can’t have kids)