Lecture 14: Animal Symbiosis

Question 1

Symbiosis

Answer 1

“Living together”

– a persistent association between two or more unrelated organisms

Question 2

Host

Answer 2

PROVIDER of resource

Question 3

Symbiont

Answer 3

CONSUMER of resource

Question 4

Interaction is classified by the effect of the …

Answer 4

symbiont on the host

Question 5

Types of symbiotic relationships

Answer 5

• mutualism
• commensalism
• parasitism

Question 6

mutualism

Answer 6

+ + interaction

both host and symbiont benefit

based on reciprocity
greater reward than cost

Note: Based on persistent association

Plant/pollen

Question 7

Why doesn’t the plant/pollunator relationship qualify as symbiosis?

Answer 7

It is mutualistic because they both benefit but not a symbiosis because its a brief interaction. Symbiosis requires persistent association.

Question 8

commensalism

Answer 8

+ 0 interaction

symbiont has a positive Benefit
host has no benefit or loss

-ie barnacle(home) and whale(no impact)

Question 9

parasitic

Answer 9

+ x interaction

symbiont has a positive benefit
host has loss or affected negatively

ie- tapworm and dog

Question 10

symbiotic interactions are ….

Answer 10

content dependent 
(more like a spectrum of interactions)

Question 11

Zooxanthellae

Answer 11

photosynthetic algae found in coral and other marine invertebrates

Question 12

facultative mutualism

Answer 12

independently

Question 13

obligate mutualism

Answer 13

organisms rely on each other for survival

Question 14

Endosymbiosis

Answer 14

internal symbiotic partner

Question 15

what two ways can an organism gain symbionts?

Answer 15

• horizontal transmission

- vertical transmission

Question 16

horizontal transmission

Answer 16

symbiont acquired through environment ( food, air, et)

Question 17

vertical transmission

Answer 17

symbiont acquired through mother

Question 18

2 primary symbiosis

Answer 18

(1) prokaryotic cell engulfs heterotrophic cell

2) organism with mitochondria engulfed another prokaryote but this time photosynthetic (eventually chloroplast

Question 19

Mutualisms: Endosymbiosis

Answer 19

• Allows organisms to acquire novel traits and metabolic capabilities
• Create habitats impossible otherwise

Question 20

Mutualisms: Endosymbiosis

Answer 20

• Allows organisms to acquire novel traits and metabolic capabilities
• Create habitats impossible otherwise

Question 21

Functions of mutualism

Answer 21

Nutrition (digestion)
Defense (predation prevention)
Communication

Question 22

Types of defense provided in mutualism

Answer 22

(1) Predation prevention
(2) Toxin production
(3) Pathogen Prevention

Question 23

Types of defense provided in mutualism

Answer 23

(1) Predation prevention
(2) Toxin production
(3) Pathogen Prevention

Question 24

Explain how Wholbachia helps with pathogen prevention.

Answer 24

protects against RNA viral infection by interfering with replication

Question 25

2 ways human body benefits from pathogen prevention?

Answer 25

(microbiome)

• Modulate immune system
• Exclude pathogenetic microbes

Question 26

Holobiont

Answer 26

Holobiont= host “ecosystem” and the

species living in and on it

Question 27

Parasite

Answer 27

organism lives in or onanother species at its expense. May harm, but don’t usually kill

Question 28

Endo

Answer 28

live within

Question 29

Ecto

Answer 29

live externally

Question 30

Parasitoid

Answer 30

organism with a larval stage within a host that it kills