Genetics L1 - Genetic Diseases

Question 1

What are homeobox genes?

Answer 1

Are a large group of similar genes that direct the formation of many bodily structures during early embryonic development.

Question 2

What is known as the master gene?

Answer 2

Homeobox gene

Question 3

What is mesenchyme?

Answer 3

A loosely organised, mainly mesodermal embryonic tissue which develops into connective and skeletal tissue, including blood and lymph.

Question 4

What is ectomesenchyme?

Answer 4

A form of mesenchyme, in the embryo consisting of neural crest cells, forms the tissues of the neck and cranium

Question 5

What is a pleiotropic gene?

Answer 5

Is a singular gene that influences two or more seemingly unrelated phenotypic traits.

Question 6

What is the function of the MSX1 gene?

Answer 6

The MSX1 gene provides instructions for making a protein that regulates the activity of other genes. The MSX1 gene is part of a larger family of the homeobox gene

Question 7

What is the function of the MSX2 gene?

Answer 7

The MSX2 protein is part of a chemical signalling pathway known as the bone morphogenic protein pathway.

Question 8

What are the three modes of inheritance of disease on a single gene?

Answer 8

Dominant

Recessive

X-linked

Question 9

The probability that presence of disease genotype will cause disease is defined as.

Answer 9

Penetrance.

Question 10

Variation in the severity of expression of a particular gene is known as.

Answer 10

Expressivity – Treacher Collins Syndrome has different variations of severity of the penetrance.