Week 11 - Genes and Inheritance lecture 2 - Pedigrees

Question 1

What are the basic patterns of inheritance (6)

Answer 1

• Autosomal recessive
• Autosomal dominant
• X-linked recessive
• X-linked dominant
• Y-linked
• Mitochondrial inheritance

Question 2

What is an example of autosomal recessive inheritance pattern

Answer 2

cystic fibrosis- genetic disorder that primary affects the lungs and digestive system due to impacted ion channels

Question 3

What is an example of autosomal dominant inheritance pattern

Answer 3

Huntington’s disease - a form of brain damage due to trinucleotide slippage (a repeated nucleotide sequence was replicated too many times)

Question 4

What is an example of X-linked recessive inheritance pattern

Answer 4

Red-green colour blindness: this affects more males (8%) than females (0.5) due to males being more likely to gain x linked recessive traits due to them only having one x chromosome

Question 5

What is an example of x-linked dominance inheritance pattern

Answer 5

X-linked hypophosphatemia - mutation of X-chromosome located PHEX protein result in abnormal absorption of Vitamin D - leading to Rickets

Question 6

Explain Y-linked inheritance pattern

Answer 6

Since the Y chromosome is only passed from fathers to their sons, Y-linked traits or disorders are only inherited by males. If a male has a Y-linked trait or disorder, he will pass it on to all of his male offspring.

Question 7

Explain mitochondrial inheritance

Answer 7

The transfer of mitochondrial genetic information which can only be passed on by the mother to her children. Hence all of her children will exhibit the trait

Question 8

What is multifactorial inheritance and what pattern will it eventually form

Answer 8

Multifactorial inheritance refers to the inheritance pattern of traits or disorders that are influenced by multiple genetic and environmental factors.

With multiple cross breeding multifactorial inheritance will result in a normal distribution of phenotypes.

Question 9

What is the small variation in genetically identical genotypes due to

Answer 9

environmental variation

Question 10

What is genetic heritability

Answer 10

Genetic heritability is the proportion/percentage of which the phenotype/trait is due to the genetics of an individual.
Shown through the twin study