36 Heredity

Flashcards on Heredity

Genotype

An individual’s genetic makeup (aa, Aa or AA).

Phenotype

Physical expression of an individual’s genotype (blue or brown eyes).

Autosomal dominant-recessive inheritance

Refers to alleles strictly dominant or recessive of non-sex chromosomes.

Punnett square

Used to predict possible genotypes of offspring between parents.

Homozygous

If 2 alleles code are the same for a trait.

Heterozygous

If 2 alleles are different for a trait.

Dominant alleles

Alleles that mask another in gene expression, represented with capital letters (A, B, C).

Recessive alleles

Alleles that are masked in gene expression, represented with lower case letters (a, b, c).

Incomplete Dominance

Heterozygous genotype results in a hybrid phenotype.

Codominance

Involves traits with multiple alleles where some alleles are equally dominant and equally expressed.

Sex-Linked Traits

Expressed on X or Y chromosome such as Duchenne muscular dystrophy, color blindness and hemophilia.

Polygenic Inheritance Patterns

Most inherited traits are controlled by effects of 2 or more genes such as eye color, height and skin color

Amniocentesis

Amniotic fluid withdrawn using needle inserted into amniotic cavity between 14-20 weeks of pregnancy.

Chorionic Villi Sampling

Occurs in week 10 and 12 of pregnancy chorionic villi tissue is withdrawn through vagina and uterus or by a needle through abdominal cavity.

Karyotype

Full set of 23 chromosome pairs can be arranged and displayed as a karyotype.