5.1.5 Homeobox Cuzzien

Question 1

What is a homeobox gene

Answer 1

Regulatory genes (180 base pairs long)
- they code for the homeodomain, which is a part of a regulatory protein and control body development
- they are highly conserved (similar across different organisms)

Question 2

What is the function of homeobox gene

Answer 2

• they control body development
  -pax 6 gene codes for eye development
• Homeobox genes are highly conserved
• they regulate mitosis and apoptosis
• respond to internal and external stimuli (stress)

Question 3

What are hox genes

Answer 3

Homeobox genes only found in animals. We have 39 in 4 different clusters. They are responsible for the position of body parts

Question 4

What is homeodomain

Answer 4

Proteins made by the homeobox, which bind to dna to switch on and off other genes thereby controlling the body plan of an organism

Question 5

What happens if mutation occurs in hox genes

Answer 5

It would be detrimental to organism and probably die

Question 6

Why do we use fruit flies to study homeobox

Answer 6

Small
Short life cycle
Easy to keep and breed
Cheap to buy
Not rare
Large cells

Question 7

What can impact the development of homeobox genes

Answer 7

Hormones can trigger certain genes to be turned on or off

External factors like temp

Or drugs like thalidomide

Question 8

WhaT is apoptosis triggered by

Answer 8

Transcription factors made by the hox genes which causes thr cytoskeleton to be broken down by enzymes / lysosomes which causes the cell to lose its shape forming ‘blebs’, which then break off to form segments which get digested by phagocytes