2 - Interspecific Interactions

Question 1

Importance and Role of Interspecific Interactions - Ecosystems

Answer 1

Affects food webs, species distribution, and ecosystem services (e.g. food supply)

Question 2

Importance and Role of Interspecific Interactions - Conservation Biology

Answer 2

Predicts species responses to change + manages invasives

Question 3

Importance and Role of Interspecific Interactions - Agriculture/Pest control

Answer 3

Helps manage pests via predator-prey + competition knowledge

Question 4

Importance and Role of Interspecific Interactions - Medicine/Microbiology

Answer 4

Key in biofilms, antibiotics, and tumour resource competition

Question 5

Competition

Answer 5

-/-

Both species harmed fighting over resources

Question 6

Predation

Answer 6

+/-

Predator benefits, prey is harmed/killed

Question 7

Parasitism

Answer 7

+/-

Parasite benefits, host is harmed but not killed (immediately)

Question 8

Mutualism

Answer 8

+/+

Both species benefit (e.g. pollination)

Question 9

Commensalism

Answer 9

+/0

One benefits, other unaffected (e.g. barnacles on whales)

Question 10

Amensalism

Answer 10

-/0

One harmed, other unaffected (e.g. antibiotics killing bacteria)

Question 11

Decomposers

Answer 11

Break organic matter at molecular level

Question 12

Detritivores

Answer 12

Eat dead matter, break it into smaller bits

Question 13

Importance of Decomposers and Detritivores

Answer 13

Recycle nutrients, keep energy flowing

Question 14

Stages of decomposition

Answer 14

Leaching → Fragmentation → Chemical alteration

Question 15

Factors affecting decomposition

Answer 15

Temperature, moisture, oxygen, substrate quality

Question 16

Cellulose Ingestion

Answer 16

Cellulase breaks down cellulose

(animal cellulase / cellulase produced by symbionts / cellulase produced by ingested microflora

Question 17

Does cellulose Digestion take place in the gut

Answer 17

No

Question 18

Fungal succession

Answer 18

Different fungi dominate at various stages of decay

Question 19

Most decomposers are…

Answer 19

Specialists

E.g. Bacteria Ideonella sakaiensis capable to break down and consuming polyethylene terephthalate (PET)

Question 20

Interspecific competition

Answer 20

Two species compete for the same limited resources (food, space, water)

Question 21

Interspecific vs Intraspecific competition

Answer 21

Intraspecific = same species

Interspecific = different species

Question 22

Effects of competition

Answer 22

↓ Growth rate

↓ size

↓ offspring quality/quantity

↑ mortality

Question 23

Resource (Exploitative) Competition

Answer 23

Indirect – one species uses up a shared resource (e.g. light)

Question 24

Interference Competition

Answer 24

Direct – species actively block others (e.g. chemical inhibition)

Question 25

Fundamental Niche

Answer 25

All conditions a species could live in

Question 26

Realised Niche

Answer 26

Where it actually lives due to competition/predation

Question 27

Competitive exclusion principle

Answer 27

Two species can’t coexist if they compete for the same resource – one wins

Question 28

Competitive exclusion principle example

Answer 28

Gause’s Paramecium experiment

Question 29

How can species coexist

Answer 29

Niche differentiation, resource partitioning, environmental variation

Question 30

Character displacement

Answer 30

Species evolve differences to reduce competition in the same area (sympatric)

Question 31

Character displacement example

Answer 31

Galapagos finches’ beak size divergence

Question 32

Character development - whats needed

Answer 32

Phenotypic differences, genetic basis, resource-linked competition

Question 33

Lotka-Volterra Model

Answer 33

Math model for species competition

Question 34

Lotka Volterra Model Assumptions

Answer 34

Each species grows alone but competes for shared, limited resources

Question 35

Outcomes of the Lotka-Volterra Model

Answer 35

Competitive exclusion (one wins) Coexistence (balance + shared resources) Unstable dynamics (extinction/fluctuation if too intense)