Lecture 3-Organisms and environment

Question 1

What three measures of fitness do environmental conditions affect?

Answer 1

• survival
• growth rates (and development)
• reproduction (production of young or fertile eggs)

Question 2

How do endotherms deal with temperature?

Answer 2

-regulate body temperature through producing heat within their bodies

Question 3

How do ectotherms deal with temperature?

Answer 3

-rely on external sources of heat, hence growth rates are often temperature dependent

Question 4

Can actual temperature be different from average air temperature?

Answer 4

-yes

Question 5

Hummingbirds and flower mites interaction?

Answer 5

-mites feed on nectar and travel in hummingbird nares to the next one= microclimate in the flower (different temperature to the surrounding air)

Question 6

Why is specific heat of water important?

Answer 6

-high
=takes 5x more heat to raise it by 1 C as it does the same mass of soil
=more stable temperature, good for life

Question 7

How does water temperature affect the oxygen availability?

Answer 7

• high temp= lower O2 available

- low temp= more O2 temp

Question 8

What causes death at high or low temperature?

Answer 8

• high= enzyme inactivation

- low= ice crystal formation

Question 9

What are lethal and sub-lethal conditions?

Answer 9

lethal= limits where an organism can live in nature

more often limited by sub lethal conditions(that reduce fitness-growth, reproductive success)

Question 10

What is forensic entomology?

Answer 10

-determining the length of time an animal has been dead by the number, sizes and development stages of insects
-need to know temperature as it is related to growth rate and development from one stage to the next as well
-development time is shorter in hotter temp
-cold temp= slower development
but temp x day= same value