Adaptation, Acclimation and Plasticity

Question 1

What is an adaptation?

Answer 1

A trait that increases the overall fitness of an organism

Question 2

What is an adaptation?

Answer 2

A trait that increases the overall fitness of an organism

Question 3

How are traits passed on?

Answer 3

If the trait is beneficial, organisms will survive to reproduction and trait is passed on to the offspring. Trait is selected for and is genetically determined, therefore heritable

Question 4

How are traits passed on?

Answer 4

If the trait is beneficial, organisms will survive to reproduction and trait is passed on to the offspring. Trait is selected for and is genetically determined, therefore heritable

Question 5

What is plasticity?

Answer 5

The ability of living organisms to change their state in response to any stimuli. Occurs at any level of complexity

Question 6

What is acclimatisation?

Answer 6

Physiological compensatory response to the environment. It isn’t heritable. May be immediate of build over time. Is often experimental

Question 7

What is any example of plasticity?

Answer 7

Rock hopper penguins are present at a variety of climates, from subtropical to subarctic climates, which os due to the species ability to express different strategies and foraging behaviour

Question 8

Whats the difference between acclimation and acclimatisation?

Answer 8

Acclimation is under experimental condition e.g. in the lab, acclimatisation is natural

Question 9

What happens to barometric pressure and atmospheric oxygen at high altitudes?

Answer 9

Both are low, meaning fewer oxygen molecules in a breath of air

Question 10

How is oxygen transported round the body?

Answer 10

Oxygen from the lungs binds to harm groups in haemoglobin. There are 4 binding sites on each Hb, Oxygen is released from the haemoglobin into the issues that need it. Red blood cells transport oxygen around he body.

Question 11

What is oxygen saturation?

Answer 11

The % of haemoglobin binding sites that carry oxygen

Question 12

What is the haemoglobin oxygen affinity?

Answer 12

how readily hemoglobin acquires and releases oxygen molecules into the fluid that surrounds it

Question 13

What happens to oxygen transport at high altitudes?

Answer 13

Oxygen transport system must respond to maintain sufficient tissue oxygen concentration, otherwise hypoxia may occur

Question 14

What are the questions asked in the case study of Andeans and Tibetans living at high altitudes?

Answer 14

Do the Tibetans and Andeans have the same/different physiological responses to low atmospheric oxygen?
Are these responses heritable?
How does the measured response influence fitness?

Question 15

How long have the Andeans and tibetans lived at 4000m for?

Answer 15

Andeans for 13 000 years, tibetans for 23 000 years

Question 16

What is erythrocytosis?

Answer 16

an increase in the number of circulating red cells above the gender-specific normal level.

Question 17

What did they find when measuring the degree of physiological stress in [Hb] shown by the Andeans and Tibetans?

Answer 17

Andeans had higher [Hb] than their closest ancestors living at low altitudes
No difference in [Hb] between Tibetans living at high altitude and their closest ancestors living at low altitudes

Question 18

What did they find when measuring the degree of physiological stress in oxygen saturation shown by the Andeans and Tibetans?

Answer 18

Andeans and Tibetans had lower oxygen saturation than their closest ancestors living at low altitudes
Andeans had higher oxygen saturation than Tibetans, suggests Andeans were less stressed by hypoxia at the same altitude

Question 19

Do tibetans and andeans have the same/different physiological responses to low atmospheric oxygen?

Answer 19

No, tibetans had a similar [Hb] saturation to lowlanders, whereas andeans had high, which shows that elevation in [Hb] is not a universal response to high altitude hypoxia

Question 20

What are the downstream consequences of hypoxia?

Answer 20

Higher [Hb] -> viscous blood -> strains heart. Its a better to deal with hypoxia, but is a trade off effect

Question 21

Are responses in [Hb] heritable?

Answer 21

Both Tibetans and Andeans had high heritability
Potential for natural selection to act in both
samples

Question 22

Are responses in oxygen saturation heritable?

Answer 22

No significant heritability in the Andean sample

Significant heritability in the Tibetan sample

Question 23

How was oxygen saturation heritable in the Tibetan sample?

Answer 23

Dominant autosomal gene for oxygen saturation
Confers 5 – 6% higher oxygen saturation
Individuals with 1 or 2 copies of this allele
experience less physiological hypoxic stress than those who are homozygous recessive at this locus

Question 24

What data was collected from the Tibetan region?

Answer 24

Oxygen saturation
Genealogy
Female fertility

Question 25

How does the measured response influence fitness?

Answer 25

No association between presence of
oxygen saturation gene and the number
of pregnancies or number of live births
Homozygous recessive mothers had lower
number of surviving children (~1.6) compared to mothers with the oxygen saturation gene (~3.7)
Increased infant mortality rates in homozygous recessive mothers