DSA 2: Introduction to Genetics

Question 1

What is lyonization?

Answer 1

Random X-inactivation in genes

*calico cats

Question 2

Mosaicism

Answer 2

Different genotypes in an individual who has developed from a single fertilized egg

• errors in cell division
• different karyotypes: down, klinefelter, turner syndromes
• ratio of normal:abnormal cells determine severity of disease

Question 3

What is the totipotency of stem cells?

Answer 3

Pluripotent

Question 4

What diseases occur from mutations in hemoglobin

Answer 4

Thalassemia: underproduction of hemoglobin
Methemoglobinemia: cannot bind heme
Sickle Cell: mutated hemoglobin

Question 5

What is special about mitochondrial DNA?

Answer 5

• double-stranded circular
• no introns
• mutation rate is 10x higher than normal DNA
• inherited from maternal line exclusively
• lack of DNA repair mechanism

Question 6

When stem cells undergo mitosis, what do they produce?

Answer 6

One stem cell and one daughter cell