Mendelian Genetics and Blood Type Inheritance

The video introduces Mendelian genetics, explaining that human cells have 46 chromosomes, with 23 inherited from each parent. It defines alleles as sections of chromosomes coding for specific genes. Using blood type as an example, it explains homozygous and heterozygous conditions, dominant and recessive alleles, and the difference between genotype and phenotype. The video also demonstrates how to use a Punnett square to predict genetic inheritance, showing how different genotypes can result in the same phenotype.

How many chromosomes do human cells typically contain?

• 23

• 92

• 46

• 69

What is an allele?

• A type of cell

• A section of a chromosome coding for a specific gene

• A pair of chromosomes

• A dominant trait

Which blood type alleles are considered dominant?

• B and O

• A and O

• A and B

• O and AB

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

• They have no alleles for a trait

• They have two identical alleles for a trait

• They have a recessive trait

• They have two different alleles for a trait

In genetics, what does the term 'heterozygous' refer to?

• Having two identical alleles

• Having a dominant trait

• Having two different alleles

• Having no alleles

What is the difference between genotype and phenotype?

• Genotype is dominant, phenotype is recessive

• Both are the same

• Genotype is the physical trait, phenotype is the genetic code

• Genotype is the genetic code, phenotype is the physical trait

Which of the following is an example of a phenotype?

• AA

• Genotype

• AO

• Blood type A

What tool is used to predict the possible genotypes of offspring?

• Allele grid

• Chromosome chart

• Genetic map

• Punnett square

If a child inherits an AO genotype, what will their blood type phenotype be?

• Type B

• Type A

• Type AB

• Type O

What percentage of children will have blood type O if both parents have AO genotypes?

• 0%

• 25%

• 75%

• 50%