1. Symbiotic Relationships Biology Mrs. Neistadt

2. *Species Interactions
*Species within a community develop close interactions, known as symbiosis.
“Sym” means together
“Bio” means life
Symbiosis means “living together” and describes the close relationships developed between species.
*Symbiotic relationships will always benefit at least one organism involved.

3. Species Interactions
*There are 5 major types of symbiotic relationships:
*Predation
*Parasitism
*Competition
*Mutualism
*Commensalism

4. *Predation
*Predation is a relationship where one organism captures and consumes another.
Predator – organism doing the capturing
Prey – organism being captured
A predator’s survival depends on its ability to catch its prey.
Ex: rattlesnake venom, spider web, etc.
A prey’s survival depends on its ability to avoid being caught.
Camouflage, mimicry, physical/chemical defenses

5. *Prey Defenses
*Mimicry – a defense where one organism resembles another that is dangerous or poisonous
There are two types of mimicry:
A harmless organism closely resembles a dangerous one
Known as Batesian mimicry
Predators learn to avoid both species
Ex: King snake and coral snake
Two harmful organisms resemble one another
Known as Mullerian mimicry
Added advantage to their already harmful adaptations
Ex: Bees and wasps have similar striping

6. Prey Defenses
*Plants have also developed adaptations to protect them from predators.
Physical defenses make them difficult to eat
Ex: Spines, thorns, tough leaves
Can produce secondary compounds
Secondary compounds are synthesized from products of the plant’s metabolism
Usually poisonous, irritating, or bad-tasting
Ex: Poision ivy and poison oak

7. *Parasitism
*Parasitism – symbiotic relationship where one organism is harmed and the other is helped
Parasite feeds on the host organism
Unlike predation, it does not result in the immediate death of the host
Ex: tapeworms can live in human digestive tract for long periods of time

8. Parasitism There are 2 different types of parasites: Ectoparasites
External parasites – live on the outside of the host
Ex: ticks, fleas, mosquitoes
Endoparasites
Internal parasites – live inside the host’s body
Ex: bacteria, protists, tapeworms

9. *Competition
*Competition – the use of the same limited resource by two or more species in the same place at the same time
Resource = anything necessity of life (water, nutrients, light, food, or space)
Competition may cause the development of different niches or physical characteristics.

10. Competition Competitive Exclusion Principle
No two species can occupy the same niche in the same habitat at the same time
Ex: Paramecia
Two species of paramecia will thrive separately, but when put together, one species is eliminated

11. *Competition
*Organisms may develop physical differences because of competition for resources.
Character Displacement – evolution of anatomical differences that reduces competition
Happens most where ranges of competitors overlap
Ex: Darwin’s finches
Species found in separate locations have the same beak size
The same species found together have different beak sizes
allows them to feed on different seeds and reduces competition

12. Competition
Organisms may develop differences in niches because of competition for resources.
Resource Partitioning – species coexist by using only part of the available resources
Ex: some birds eat the same insects, but hunt for them in different places

13. *Mutualism
*Mutualism is a symbiotic relationship where both organisms are helped in some way.
Ex: *Plants and their pollinators
Pollinators feed on the plants and pollen gets stuck to them.
Pollen is deposited on the next plant, allowing the plants to reproduce sexually.

14. *Commensalism
*Commensalism is a symbiotic relationship where one organism benefits and the second is neither harmed nor helped.
Ex: *Whales and Barnacles
Barnacles have the benefit of moving through waters attached to the whale
The whale receives no benefit,
but is not harmed either

15. Name the Symbiotic Relationship…
A eagle hunting a mouse.
Predation
A tick feeds on the blood of its host and may carry disease
Parasitism
The flower lives on a tree and absorbs the water from runoff and the tree is unaffected.
Commensalism
Two different types of finches feeding on seeds.
Competition
An ant protects a caterpillar from predators and the caterpillar produces a sweet liquid for it to drink.
Mutualism