Drosophila Genetics

Question 1

How long does it take for Drosophila to develop from an egg to an adult?

Answer 1

4 Days.

Question 2

Homeotic Transformation

Answer 2

One body part is replaced by another (e.g. antennae become legs).

Question 3

Balancer Chromosomes:

Answer 3

1. Carry a dominant marker mutation
   2 Are homozygous lethal
2. Carry chromosomal inversions, and these suppress crossing over events in meiosis

Question 4

Hox Genes

Answer 4

Regulate the identity of body parts. They are expressed in spatially restricted domains. The order of Hox genes parallels the order of body parts in which they are expressed.

Question 5

Antennapedia complex

Answer 5

Cluster of genes responsible for the front of the body

Question 6

Bithorax Complex

Answer 6

Cluster of genes responsible for the back of the body

Question 7

Bicoid

Answer 7

A gene that is required for the “head” (anterior sections)

Question 8

Nanos

Answer 8

A gene that is required for the anterior sections

Question 9

Bicoid mRNA and protein forms a gradient from?

Answer 9

Anterior to Posterior

Question 10

Nanos mRNA is localized where? And the protein forms a gradient from?

Answer 10

Posterior to Anterior

Question 11

Expression of anteroposterior-axispatterning proteins (Segmentation Genes)

Answer 11

Gradient: Bicoid and nanos establish a gradient.

Gap Genes: Subdivide the embryo along the anterior/posterior axis and encode transcription factors that regulate the expression of the gap genes.

Pair Rule: Divide the embryo into pairs of segments and encode transcription factors that regulate the expression of the segment polarity genes.

Segment Polarity: Set the anterior/posterior axis of each segment.