BIOLOGICAL ASSOCIATIONS

LECTURE DELIVERED BY:

 Biological associations are relationships or interactions among living organisms.  No living organism can exist as an isolated entity, so therefore a living organism A goes into a relationship with another living organism B voluntarily or involuntarily. For instance female Anopheles mosquito goes into relationship with Humans voluntarily while Humans goes into the relationship involuntarily.  It must also be noted that these associations could be beneficial, harmful or even neutral. For instance the association between a Butterfly perching on a Hibiscus plant is beneficial to both of them. In this case the Butterfly gets food in form of sugary juice called nectar while it help pollinate the flowering plant by picking up pollen grains unconsciously. When you go ahead to consider the one of Human and Hookworm ( a dangerous Nematode found in the small intestine that sucks blood excessively), you would see that it is beneficial to Hookworm but harmful to Humans.

 MUTALISM  COMMENSALISM  PARASITISM  PREDATION

 Mutalism is an association between two different organisms, in which both of them benefit. For instance if an organism A goes into an association with another organism B, and both of them derive benefit from this association, then it is termed ‘’ MUTUALISM’’.

 Alga and Fungus  Leguminous plant and Bacterium  Termite and Trichonympha ( a Protozoon)  Ruminant animal and Escherichia (a Bacterium)  Butterfly and Hibiscus plant

OK……

 Commensalism is an association between two different organisms in which only one organism benefits while the other is neither harmed nor benefits. For instance an organism A goes into an association with another organism B, and organism A derive benefits while organism B does not derive benefits and neither is it harmed, then it is termed “COMMENSALISM”.

 Humans and Bacteria( e.g Bacteriodes succinogenes) in the large intestine  Shark and Remora fish  Oyster and crab

 Parasitism is an association between two different organism in which one of them benefits while the other is harmed. The organism that benefits is called the PARASITE while the one that is harmed is called the HOST.

 Human and Tapeworm  Human and Roundworm  Flowering plant and Mistletoe  Human and female Anopheles mosquito

 Predation is association between two different organisms, in which one called the PREDATOR attacks and devours the other called the PREY. Have you ever seen a documentary where a Lion preys on an Antelope before, I bet you have.

 Lion and Antelope  Hawk and chicks of domestic Hen  Kingfisher( a Bird) and Tilapia fish  Rattle snake and Rat

I bet you have been involved in one competition or the other before. Maybe a Football competition, or a singing competition or even a thug of war competition

 INTRA-SPECIFIC COMPETITION  INTER-SPECIFIC COMPETITION

 LETS ANSWER THOSE QUESTIONS TOGETHER, SHALL WE?

 Competition refers to an interaction among organisms for limited environmental resources. It could exists in different forms and for different reasons.

 There could be competition among only organisms of the same species, and this is termed INTRA-SPECIFIC COMPETITION. For instance competition among Humans for limited food supply. In this case we see that Humans belong to a single species Homo sapiens. The word INTRA means within while SPECIFIC means species. That is INTRA – SPECIFIC COMPETITION is competition within a single species.

 Competition for grains among domestic chicks  Competition for space among Maize plants  Competition for sunlight among Okra plants  Competition for water among Water leaf plants

 There could exists competition among organisms of different or several species, and this is termed INTER –SPECIFIC COMPETITION. It is important to note that SPECIFIC means and INTER means several. That is INTER- SPECIFIC COMPETITION means SEVERAL SPECIES COMPETITION.

 Competition between Tiger and Hyena for limited supply of antelopes  Competition between Toads and Frogs for limited supply of insects  Competition among Carpet grass and Elephant grass for limited water

 Limited supply of water  Limited supply of nutrients  Limited supply of sunlight  Limited supply of food  Limited growing space  Limited sex partners

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