Lecture 12: Multiple Alleles

What is the diploid state in terms of gametes?

Gametes are haploid and come together to form a diploid individual.

What are homologous chromosomes?

Chromosomes that are similar but not always identical to each other.

What are sister chromatids?

Sister chromatids are identical copies of a chromosome.

What did Mendel recognize in his pea plants?

Mendel recognized that traits were inherited as discrete units called genes.

What is the genotype for green peas according to Mendel's observations?

Big G, Big G or Big G, little g.

What is the phenotype for yellow peas?

Little g, little g is the only way to get the yellow color.

What defines the dominant allele in a simple Mendelian dominance scenario?

The presence of one copy of the dominant gene product covers up the phenotype of the recessive allele.

What is the phenotypic ratio observed in a typical Mendelian cross?

A 3:1 ratio for dominant to recessive traits.

What are multiple alleles?

More than two alleles for a gene that can exist within a population.

What blood types are determined by multiple alleles in the ABO system?

A, B, and O blood types.

What does the A allele code for in terms of blood type?

The A allele codes for the A antigen present on red blood cells.

What type of antibody does type A blood produce?

Type A blood produces anti-B antibodies.

Why is type O blood considered the universal donor?

Type O blood does not have A or B antigens on its surface, making it compatible with any blood type.

What indicates a positive RH factor in blood typing?

The presence of the D antigen.

What is hemolytic disease of the newborn?

A condition that can occur when an RH-negative mother has an RH-positive baby.

What does the probability of offspring being type A entail in genetics?

It involves calculating ratios based on parental genotypes.

What method is used to calculate the probability of offspring blood types?

The multiplication rule in genetics.

What is the key takeaway regarding inheritance patterns in blood groups?

Understanding dominance, codominance, and multiple alleles is crucial for determining blood types.