Dr. HSA explains genetic disorders, focusing on modes of inheritance. The video covers chromosome structure, alleles, and karyotypes. It details autosomal dominant and recessive inheritance, as well as X-linked dominant and recessive patterns, using examples to illustrate each concept.

What is the primary function of chromosomes in cells?

• To contain DNA and genes

• To replicate proteins

• To transport nutrients

• To store energy

What are alleles?

• Identical genes on different chromosomes

• Alternative forms of a gene at the same locus

• Proteins that bind to DNA

• Mutations in the DNA sequence

In autosomal dominant inheritance, what is the chance of an affected parent passing the mutation to their offspring?

• 50%

• 100%

• 75%

• 25%

Which of the following is true about autosomal recessive inheritance?

• Only one mutated gene is needed for the disorder to manifest

• It affects only males

• It may skip generations

• It requires a Y chromosome

What is the probability of offspring being carriers if both parents are carriers of an autosomal recessive disorder?

• 25%

• 75%

• 0%

• 50%

In X-linked dominant inheritance, what is the chance of a mother with the disorder passing it to her children?

• 25%

• 50%

• 75%

• 100%

If a father has an X-linked dominant disorder, which of his children will be affected?

• 50% of sons

• 50% of daughters

• All daughters

• All sons

In X-linked recessive inheritance, why are males more frequently affected?

• They have two X chromosomes

• They inherit the disorder from their fathers

• They have only one X chromosome

• They are carriers of the disorder

What happens to the daughters if the father has an X-linked recessive disorder and the mother is normal?

• All daughters are affected

• All daughters are carriers

• 50% of daughters are affected

• 50% of daughters are carriers

In X-linked recessive disorders, why is male-to-male transmission not observed?

• Fathers pass the Y chromosome to their sons

• The disorder is only passed through the Y chromosome

• Males do not have X chromosomes

• The disorder is only passed through mitochondrial DNA