Animals In The Extemes

Question 1

How is haemoglobin adapted at high altitude environments?

Answer 1

It has higher oxygen affinity

Question 2

Small animals have a large surface area to volume ratio, what are the issues with temperature and water?

Answer 2

Temperature: risk of overheating and temperature loss during nights

Water: larger surface area leads to increased evaporation

Question 3

What are the three main strategies in desert animals?

Answer 3

Evaders
Evaporators
Endurers

Question 4

What do evaders do?

Answer 4

Avoid exposure to extreme climates due to rhythmic activity patterns, burrowing, estivation (summer sleep)

Question 5

What do evaporators do?

Answer 5

Dependent on a reasonable water supply to allow them to cool down by the use of evaporation

Question 6

What do endurers do?

Answer 6

Usually large mammals and can tolerate high fluctuations in body temperature and hydration

Question 7

Where can microclimates in the desert occur?

Answer 7

10cm below the sand conditions are more stable

Question 8

What are some examples of locomotor tricks in desert animals?

Answer 8

Alternating feet in desert lizards, sidewinder snakes and cartwheeling desert spiders

Question 9

What are the morphological tricks of the desert snail in order to avoid over heating?

Answer 9

Highly reflective surface (95% reflection of sunlight)

Apex of shell is cooler inside and the snail will retract into this compartment during the day

Question 10

What is Allen’s rule?

Answer 10

Animals adapted to cold climates have shorter limbs and body appendages than animals adapted to warm climates

Question 11

What are the morphological tricks of the black tailed jackrabbit?

Answer 11

Specialised areas of bare skin which contains a network of blood vessels for heat exchange (“radiators”)

Question 12

What is the dark flank for in the Thompson’s gazelle?

Answer 12

The dark flank absorbs heat better compared to the rest so they can orientate themselves to control body temperature

Question 13

What percentage of water loss can camels endure?

Answer 13

30%

Humans 10-12%

Question 14

What happens to an animal when they become dehydrated?

Answer 14

The blood cells shrink which leads to death because you cannot extract any oxygen

Question 15

How can camels replenish the water deficit?

Answer 15

By drinking very rapidly (200L in 3 mins)

Water is temporarily stored within the gut in order to prevent big fluctuations in plasma osmolarity

Question 16

What is another way to conserve water?

Answer 16

Urinate less through having more concentrated urine

Question 17

Where does most of the absorption of water and salts take place in the kidney?

Answer 17

The first part of the tubule called the proximal convoluted tubule

And loop of Henle

Question 18

What do the ascending and descending limbs of the loop of Henle do?

Answer 18

Thin descending limb contains water channels but it is impermeable to salts

Thick ascending limb contains salt transporters but it is impermeable to water

Question 19

Do desert animals have long or short loops of Henle and why?

Answer 19

Very long loops of Henle because the longer the loop the more concentrated the gradient and urine

Question 20

What is special about the kangaroo rat?

Answer 20

They have a perfect water balance so there is no need for them to drink any water at all

Question 21

What are the physiological tricks of conserving water in desert beetles?

Answer 21

Have a condensation chamber for water which evaporates from spiracles