Organisms and Populations Test - 8

Human population growth curve is S-shaped in which at initial stage growth is slow followed by exponential growth and finally again start declining to follow sigmoid curve growth.

Interdependence of mother and infant signifies a symbiotic relationship between mother and infants. In symbiosis both the individual interacting get benefited from each other.

Pediculus is a species of louse that infects human. It is also called as male human head louse. It sucks bloods from heads so, it is a kind of parasite that harms the host.

The interaction between two species in which both are benefited is called mutualism. Anabaena and Azolla help each other in obtaining food. Anabaena is a nitrogen fixing algae.

Negative interactions includes completion, predation, parasitism and amensalism. Pencillin and Streptomycin prohibits the growth of micorbes or kills the microbes that is a kind of negative interactions.

Natality or birth rate is the number of birth in a given period in the population that are added to initial population. Actual birth rate under environmental condition is much less than total birth because all organisms do not survive adulthood due ot predation, completion etc.

J-shaped growth curve is characteristic of small population of reindeer experimentally reared in natural environment in which growth occurs at very fast rate due to availability of sufficient natural resources.

Mutualism is a kind of interaction between two species living in same habitat in which both get benefited from each other. Adamsia and Eupagurus help each other in obtaining food so it is an example of mutualism.

The group of individuals living in as defined geographical area share or compete for similar resources and potentially interbreed forms a population. Interbreeding means sexually reproducing organisms but asexually reproducing organisms also form population ecologically.

A species is a group of individual organisms that interbreed and produce fertile, viable offspring. According to this definition, one species is distinguished from another when, in nature, it is not possible for matings between individuals from each species to produce fertile offspring.