Lecture 11-12 Trophic Relations and Climate Change

Question 1

Trophic Levels.

Answer 1

Primary producers=plants
primary consumers=herbivores
Secondary consumers= carnivores that eat herbivores
Tertiary consumers=carnivores
Decomposers= eat dead organic matter

Question 2

What does the pyramid shape represent in the trophic levels

Answer 2

they represent decreasing biomass

Question 3

Difference between food chains and food webs

Answer 3

Food chains demonstrate who eats who and food webs and an entire array of food chains, much more complex

Question 4

Indirect effect on species

Answer 4

One species directly effects another, which indirectly affects a third species

Exploitative/ Scramble competition is an example

Question 5

Trophic Cascades

Answer 5

interactions between 2 trophic level cascades that has an indirect effect on a third level

Question 6

Who proposed the green world theory? What is it?

Answer 6

Smith and Slobodkn said that the reason the earth is green is because carnivores are eating herbivores protecting plant life on earth

Example of trophic cascade

Question 7

Top-down control

Answer 7

Abundance is kept low due to predation (removal of predator)

Question 8

Bottom top

Answer 8

Abundance is kept low due to resource limitation

Question 9

How does plant-herbivore interactions lead to diversification

Answer 9

Plants have been building defences to protect themselves from herbivores, however herbivores are also adapting and build resistances to these defences, so there is a co-evolutionary arms race between the two

Question 10

How do vertebrate herbivores deal with plants differently compared to insects

Answer 10

V. herbivores will ingest low quantities of a variety of plants so they don’t build high toxin levels that are in the plants

Question 11

List the major threats to biodiversity

Answer 11

climate change
overexploitation
habitat destruction
pollution
invasive species

Question 12

Synergistic Effects

Answer 12

Chemical effects that have a much more lethal effect when paired with other chemicals rather than their potential damage when they are alone

Question 13

How is CO2 a greenhouse gas

Answer 13

1. sun rays hit the earth’s
   atmosphere
2. these rays are absorbed by the surface
3. this absorbance emits infrared radiation which gets CO2 converted into heat

Question 14

how is the climate changing?

Answer 14

1. Circulation/ Hadley cells are stronger causing poleward shifts up 30 degrees
2. Extreme weather events
3. Climate changes effect organisms

Question 15

what are the different possibilities of what may happen to organisms as climate changes

Answer 15

acclimation: acclimate to weather
extinction
adaptation: they will start forming traits to adapt to weather changes
Range shift: moving to more suitable conditions

Question 16

Example of how acclimation works

Answer 16

Porcelain crabs are able to withstand colder temperatures now due to exposure to colder temperatures at a gradual rate

Question 17

How does climate change effect hares?

Answer 17

Hares change their coat furs in the winter to help camouflage but due to warming years, hares are unable to stay hidden in conditions where there should be snow but aren’t, making them easy prey for predators

Question 18

Are pikas threatened by climate change?

Answer 18

In Canada pikes are running out of space at mountain tops, because they do very well in cold conditions

However in America they seem to be doing fine