Giving examples describe the following biotic factors/ interactions among organisms.

a) Predator-prey/ predation
-A predator is an animal that hunts/ kills another/ other animals (prey) for food; example is a dog and hare; preys device/ have survival mechanisms in their habitats not to be eaten/ killed; to survive and reproduce/ propagate their lineage; they run faster/ have strong hind muscles; camouflage with environments; mimic the predators; some emit some chemicals/ smell that turn off the predators; some have a good sense of smell to detect predators; others e.g. porcupines use quills/ spines while others e.g. grasshoppers use spikes to fight off predators;
-On the other hand predators also evolve/ device means to be able to survive in such an ecosystem; e.g. running faster; camouflaging with the environment; mimicking preys; sharp eye sight; strong sense of smell; produce venom/ poison that paralyze/ kill the prey; some have strong jaws, claws, long and sharp canines e.g. dog, talons e.g. hawks to capture the prey;
b)Symbiosis.
-This is a close/ long term association between two organisms of different species where two mutually benefit from each other; for example bacteria in the rumen/ gut of herbivore; which help the herbivore to digest cellulose; as they are sheltered by herbivore; the bacteria found in the human digestive system/ gut/ colon; are also sheltered by humans; as they help in synthesis of vitamin K/ B12/ ensure microbial balance; the nitrogen fixing bacteria on the root nodules of leguminous plants; benefit from the food and shelter offered by the plants; as they facilitate conversion of free atmospheric nitrogen into forms that can be readily absorbed by the plants; mycorrhiza and coniferous trees; mycorrhiza absorb mineral salts for plant use; while coniferous trees provide food/ organic materials to the mycorrhiza; lichen (association between blue green algae and fungus); blue green algae provides nutrients/ carries out photosynthesis; while the fungus absorbs water and provides a point of attachment for algae;
c)Parasitism.
 This is a kind of interspecific relationship/ association where one member/ organism/ parasite benefits while the other/ host is harmed/ loses; (it is also called antagonistic/ antipathetic symbiosis); for example a tick/ parasite sucking blood/ nutrients; from a cow/ host; making the cow anemic/ transmitting disease/ destroying the skin/ making it malnourished; parasites can either be ecto parasites/ external parasites; or endo parasites/ internal parasites;
d)Competition
-This is an association where two/ more organisms depend on the same limited resources e.g. food, light, water, mates and shelter; e.g. zebra and gazelle competing for grass; in competition organisms which are poorly adapted die; or migrate; the organisms which are well adapted survive hence the species increases; competition can be interspecific; or intraspecific;
e)Saprophytism.
-This is an association where organisms obtain nutrients from dead decaying matter causing decomposition; e.g. bacteria depending on dead animal; the saprophytes release enzymes which digest the decaying matter into simpler products which are directly absorbed into their bodies; saprophytes help to recycle nutrients; reduce the bulk of waste material and improve soil fertility;