2. Symbiosis in Plants and Animals
• Symbiosis means “living together”.
• A relationship between two or more
different species interacting with
each other.

3. Parasitism
Commensalism Mutualism
SYMBIOSIS

4. Epiphytes
• Epiphytes are small
green plants found
growing on other plants
for space only.
• It do not obtain
nutrients but its can
make its own food by
photosynthesis.
• Has specialized roots to
anchor itself firmly.
• E.g- pigeon orchids
- ferns
- mosses

5. • It has swollen stem at its
base (false bulb).
• It roots:-
– Has special roots (aerial
roots) to absorb moisture
from the surrounding.
– Coated with a spongy layer
(velamen) : prevents root
o Pigeon orchid tissues from drying out.

6. • Is an animal
commensal attached
to another animal
(its host).
• examples:
 Vorticella (epizoic)
and daphnia (host).
 Cyclop (host) and • Epizoics (remora fish) attach
vorticella (epizoic). themselves to the bodies of
 Barnacles (epizoic) these hosts (the shark) for free
and crab (host).
transport, and feed on leftovers
from their hosts’ meals.

7. Mutualism
• Is an interaction between 2 species in which both
organisms benefit.
• Both organisms depend on each other to survive.
Example of interaction :
o Lichen – combination of a green
algae and a fungus
o Green algae- carry out
photosynthesis and supplies food
and oxygen to fungus.
o Fungus- gives shelter, water, carbon
dioxide, and nitrogenous compounds
Lichen… to green algae.

8. Parasitism
• Is a relationship between two organisms in which
one organism (parasite) and the other (the host) is
harmed.
o Fleas on the surface of
a host’s body…
o A tapeworm which is
live in a human
body…

9. Endoparasites Ectoparasites
• Parasites that live in another • Parasites that live on another
organisms (host). organisms. (host).
• Examples are: • Example are:
- roundworms :(on animals/human)
- tapeworms - ticks
- flukes - lice
• The host usually loses nutrients to the - fleas
parasites. :(on plants)
• Adaptations: - mealy bugs
– they have specific protection cuticles - aphids (plant lice).
and produce mucus and anti-enzymes
secretion. • Adaptations:
– Less nervous system and sense – They have sharp mouths for sucking,
organs. biting and hooking.

10. • A type of interaction where living organisms feed on dead
organic matter for food.
• Examples are: mushroom, mucor, bracket fungus,
sporangia.
o Bracket
fungus
o Mucor sp. o Saprophytic mushroom

11. • Interaction between two organisms which one will hunt
and kill the other for food. predator
prey
* The prey-predator relationship helps to control the
population of different animals in an ecosystem.

12. Prey increases
Predator Predator
decreases increases
Prey
decreases