Unit 11 #2 - Community Ecology

Question 1

Community

Answer 1

All the organisms that live together in the same time and place.

Question 2

Niche

Answer 2

how organism interacts with biotic (living) and abiotic elements
of the environment (its lifestyle)

Question 3

Habitat

Answer 3

where the organism lives (its home)

Question 4

Biotic potential

Answer 4

How fast a population grows if there is no biotic or abiotic limits (it is represented by an exponential graph of number of individuals vs time)

Question 5

Do plants have specific niches along a transect?

Answer 5

Yes, plants have specific niches along a transect, as along a transect the environment changes along with the conditions. The place where the soil changes abruptly is called ecotone.
As an example, in rocrocksky outcrop, which are serpentine soil, different species lives on different parts (far is the normal soil, then there is the ecotone, and then the serpentine soil/near rocks).

Question 6

Difference b/w fundamental and realized niche and an example

Answer 6

Fundamental niche: the dream lifestyle
Realized niche: the real lifestyle

Example: Chtamalus live on parts of rocks under water near the surface (this is their realized niche), but they want to go down, except there are other organisms there (this is their fundamental niche)

Question 7

Resource partitioning example

Answer 7

Lizards inhabit and specialize in different areas of the tree so they do not compete with one another

Question 8

How is Competitive exclusion avoided

Answer 8

Evolution goes to ressource partitioning instead of competittive exclusion to prevent species froom being out-competed. ie lizards co-habite in different areas of trees

Question 9

Character displacement and 2 examples

Answer 9

species evolve to look different when they live togheter to avoid competition for food for instance.

ie finch beak different in birds that are on the same island (same island=allopatric species, diff islands=sympatric species)

ie coywolf in quebec become bigger to adapt in hunting white-tale deer

The fact that they specialize their beaks to avoid competiton is ressource partitioning

Question 10

An example of predation

Answer 10

caribou population decreases as population of its predator (coy-wolf) increases because in contrast to them, caribous are affected by human interactionsand have no tolerance to brain worm.

or

Didinium is a predator to paramecium, when heterogeneous space then there are more paramecium becasue they can hide

Question 11

An example of predator-prey coevolution

Answer 11

caribou and wolf both evolve to run faster to catch the other/survive or with hare and lynx

Question 12

Name 6 defences against predation with an exmaple for each

Answer 12

1-camouflage (cryptic colouration)
2-Poisonous (cane toad)
3- Chemical defense (milkweed are poisonous except to Caterpillar monarque that becomes poisonous for protection)
4-Warning colouration (skunk)
5-Batesian mimicry (Viceroy butterfly colour to advertise poisonous like monarch)
6-Mullerian mimicry (2 species use same signal to show dangerous ie wasps and bees yellow stripes)

Question 13

An example of coevolution

Answer 13

Grazers remove species from soil so grass can grow, in exchange grazers have food supply

or

us and cabbages as PTC non-tasters have evolved not to taste bitterness of cabbages produced to protect themselves, good for them and us because more produced.

Question 14

what are the 3 types of species interactions

Answer 14

competition, predation, symbiosis

Question 15

What are the 3 types of symbiosis and and exmaple for each

Answer 15

1-mutualism: both species benefit (cyano bacteria extract N in atmosphere to produce sugar by photosynthesis which helps the fungus and in return the fungus gives the bacteria water and salt
2-commensalism: 1 species gains and other not harmed (mite that sticks on human skin)
3-paratism: host is harmed (meningeal worm for caribou)

Question 16

Do parasites evolve to be less or more harmful

Answer 16

parasites can veolve to become less harmful to keep their hosts alive ie myxomatosis diseasease in rabbits or small pox immnunity developped and less virulent.

Question 17

What is necessary to maintain diversity (2)

Answer 17

predators and disturbance ie if starfish removed mussels dominate

Question 18

Keystone species and example

Answer 18

a species necessary to create a particular ecosystem ie beavers flood areas for wetland species to live or sea otters prevent sea urchin overpopulation that eats everything

Question 19

Biological succession

Answer 19

Plants need nitrogen. In general, lichen can grow on rock and soil, then we will see bushes, then trees. When this process starts off with the nutrient present as with soil to climax community (full forest) is is a secondary succession
If rocks to climax community, then it is primary succession.

*this is part of decomposition as decomposed matter goes in the soil