Science module 10 alleles and shit

What is an alternative form of a gene?

Allele

What does it mean if an organism is homozygous for a trait?

It has two matching alleles.

What does Mendel’s law of segregation state?

Alleles separate from each other.

What does Mendel’s law of independent assortment state?

Alleles assort independently into gametes.

In a Punnett square, what is the ratio of genotypes and phenotypes?

It depends on the specific cross, but typically includes homozygous dominant, heterozygous, and homozygous recessive outcomes.

What is the genotype of the other parent in a cross where one parent is homozygous dominant?

It depends on the alleles involved, but it could be heterozygous or homozygous recessive.

What do pedigree charts show?

How alleles are passed from generation to generation.

What do Roman numerals in a pedigree diagram represent?

The generation number.

What do circles and squares represent in a pedigree chart?

Circles = females, squares = males.

What do shaded symbols in a pedigree chart mean?

Half shaded = carrier; Fully shaded = affected by disorder.

In incomplete dominance, what is the phenotypic ratio?

1 red: 2 pink: 1 white.

What does codominance mean?

Both alleles are fully expressed.

If a disease is codominant, which offspring display both traits?

Heterozygous individuals (e.g., Hb^A Hb^S for sickle cell trait).

How many alleles determine human blood type?

Three (A, B, O).

What is the genotype for Type O blood?

ii (recessive).

What is an example of a heterozygous blood genotype?

IAi or IBi.

Why are males more likely to have sex-linked disorders?

They only need one affected allele, while females need two.

Do linked genes segregate independently?

No, if they are very close together on the same chromosome, they tend to stay together.