Mitosis and apoptosis, and factors affecting the expression of regulatory genes

Question 1

What is apoptosis and mitosis?

Answer 1

• mitosis
  
  • results in cell division and proliferation
• apoptosis
  
  • programmed cell death

Question 2

WHat is the role of mitosis and apoptosis??

Answer 2

essential in shaping organisms

Question 3

WHat is the role of mitosis?

Answer 3

• increase the number of cells leading to growth

Question 4

What is the role of apoptosis?

Answer 4

• consider how a sculptors works to give shape to a block of wood or stone
  
  • the shape of the material is revealed as material is removed bit by bit
• this is one of the way apoptosis shapes different body parts
  
  • by removing unwanted cells and tissues
• cells undergoing apoptosis can also release chemical signals
  
  • stimulates mitosis and cell proliferation
  • leading to the remodelling of tissues

Question 5

What regulates mitosis and apoptosis?

Answer 5

Hox genes

Question 6

What are the general factors influencing the expression of regulatory genes

Answer 6

environment, both internal and external conditions

Question 7

WHat is stress?

Answer 7

• can be defined as the condition produced when the homeostatic balance within an organism is upset

Question 8

When do the factors have the largest influence?

Answer 8

greatest impact during the growth and development of an organism

Question 9

How did thalidomide cause deformities?

Answer 9

• prevented the normal expression of a particular Hox genes
• drugs can also affect the activity of regulatory genes
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Question 10

How is thalidomide used today?

Answer 10

• this property is being exploited to stop the development of some tumours
• it is believed that thalidomide prevents the formation of networks of capillaries
  
  • which are necessary for some tumours to grow and develop