Blood Group Genetics and Alleles

The video tutorial discusses the concept of multiple alleles in genetics, explaining that while most genetic systems have two alleles for a character, some have more, known as multiple allelism. The blood group system is used as an example, with three alleles (IA, IB, and i) determining blood types. The video explains how these alleles combine in individuals to form different blood groups, illustrating concepts like codominance. It emphasizes that multiple alleles exist in populations, not individuals, and summarizes the possible allele combinations and resulting phenotypes.

What is the typical number of alleles for a genetic character?

• Two

• One

• Four

• Three

What term is used when more than two alleles exist for a character in a population?

• Codominance

• Homozygosity

• Multiple allelism

• Recessiveness

Which of the following is NOT an allele in the blood group system?

• i

• IB

• IA

• IC

What does the allele 'i' in the blood group system produce?

• Both Antigen A and B

• No antigen

• Antigen B

• Antigen A

How many alleles does an individual have for the blood group system?

• One

• Four

• Two

• Three

Which blood group results from the genotype IAIB?

• A

• B

• O

• AB

What is the blood group of a person with the genotype ii?

• A

• B

• AB

• O

What is the term for when both alleles express themselves in a heterozygous individual?

• Codominance

• Incomplete dominance

• Recessiveness

• Dominance

In the context of blood groups, what does codominance mean?

• One allele suppresses the other

• Neither allele is expressed

• Both alleles are expressed equally

• Only one allele is expressed

How many alleles are present in the human population for the blood group system?

• Four

• One

• Two

• Three