Question

Define mutualism.

Answer 1

Hint: The organisms of different populations interact with each other in a community. These interactions can be positive or negative. One of such types of interaction is symbiotic association.

Complete Answer:
Mutualism is a kind of interspecific interaction in which members of two different species favor the growth and survival if each other and their association is obligatory. It is a positive interaction between two organisms that favor the growth and survival of each other so that both species are benefitted. So mutualism is a functional association.

- In this type of interaction, the members have widely different requirements and are so interdependent that they cannot survive separately.
- The best example of mutualism is lichens. It is a symbiotic association of a green alga called phycobiont and a fungus called mycobiont. The core of the lichen is formed of green algal cells which photosynthesize food for themselves and also for the fungus. The fungal hyphae form a protective cover around the algal cells. Algal cells also get moisture and minerals from them.
- Mycorrhizae is another example of mutualism between the hyphae of fungus and the roots of about 80% higher plants. The roots provide energy-yielding carbohydrates and shelter to the fungus while the latter helps in the absorption of water, minerals, etc. and produce growth promoting chemicals and secrete antibiotics to provide protection from pathogenic organisms.
- Another example is the pollination of flowers by insects. The insect gets nectar and pollen as food while for plants pollination is essential for seed formation and continuity of race. For example, pollination of yucca plants by the female yucca moth- Pronuba yuccasella.

Note: Mutualism is an obligate relationship between two organisms that means they are dependent on each other in some way or other for their survival. The two organisms can be plants and animals or one plant and another animal.