Suggest how hypoxia may have evolved
- Survival advantage at higher altitudes
- Natural selection worked on the gene
- Gene is heritable
What is a negative consequence of higher haemoglobin levels?
- Blood is more viscous
- Strains heart
The Tibetans had higher nitric oxide levels- what is the advantage of this at high altitudes?
- Increased vasodilation
- Greater area for blood to pass through
- Oxygen more easily transported to tissues
In the case study of living at high altitudes what did the andeans and tibetans haemoglobin and oxygen saturation levels show?
Andeans
- Increased haemoglobin concentration
- Low oxygen saturation
Tibetans
- Low oxygen saturation but not as low as Andeans due to length lived there being double
What is hypoxia?
A deficiency of oxygen reaching the tissues
What is the difference in pressure and atmospheric oxygen levels at high and low altitude?
High altitude- low pressure, low oxygen
Low altitude- high pressure, high oxygen
What is plasticity and 2 facts about it?
Plasticity= Ability of living organisms to change their ‘state’ in response to any stimuli
1) Occurs at any level of complexity
2) Limited
What is accumulation and 2 facts about it?
Accumulation= Physiological compensatory response to environmental change
1) Short term response
2) Not heritable
What is the definition of an adaption?
A trait that increases the fitness of an organism in its environment
