Ch9 - Homeotic Selector Genes

Question 1

Homeotic selector genes

Answer 1

after segmental boundaries are set, the characteristic structures of each segment are specified by homeotic selector genes

Question 2

2 regions of chromosome 3 have the most homeotic genes

Answer 2

• the Antennapedia complex

* the Bithorax complex

Question 3

The Antennapedia complex

Answer 3

give the identity of the head and thoracic segments

Question 4

The Bithorax complex

Answer 4

give identity to the
• 3rd thoracic segment
• abdominal segments

Question 5

3 thoracic segments

Answer 5

1. legs
2. legs and wings
3. legs and halteres

Question 6

The initial domains of homeotic gene expression is influenced by

Answer 6

gap genes and pair-rule genes

Question 7

All homeotic genes are regulated…

Answer 7

negatively by all the homeotic gene products expressed posterior to it

Question 8

Identities of segments must

Answer 8

be stabilized so differentiation can occur

Question 9

Transcription patterns stabilized…

Answer 9

locked into place by alteration of chromatin

Question 10

Transcription stabilization (chromatin) maintained by

Answer 10

Trithorax proteins

Question 11

Repression of homeotic genes maintained by

Answer 11

Polycomb proteins