Lecture 13- Chromosomes

Question 1

What did the Chromosomal Theory of Inheritance state?

Answer 1

Genes are found at specific locations (loci) on chromosomes & the behavior of chromosomes during meiosis can explain Mendel’s laws of inheritance

Question 2

On which chromosome is the SRY gene found? What does it code for?

Answer 2

Y chromosome / codes for testes

Question 3

What does it mean for a trait to be the wild type?

Answer 3

Wild type (w+) refers to the phenotype of the typical form of a species as it occurs in nature

Question 4

What does it mean for a trait to be the mutant type?

Answer 4

Mutant type (w) refers to a phenotype that differs from the normal

Question 5

What are linked genes? What is their significance?

Answer 5

When genes are close together on the same chromosome, they are said to be linked. Due to their close proximity, linked genes with be inherited as a unit more frequently than not. Linked genes violate Mendel’s Law of Independent Assortment

Question 6

What is a barr body?

Answer 6

Inactivated X-chromosome in cells with more than one X-chromosome

Question 7

What is X-inactivation?

Answer 7

X-inactivation is a random process by which X-chromosomes are rendered inactive in cells with more than one X-chromosome

Question 8

What type of fruit fly did Thomas Hunt Morgan use in his experiments?

Answer 8

Drosophila melanogaster