IgM antibodies are produced first in a humoral immune response and tend to be of low affinity.

IgM molecules form pentamers that are stabilized by a single J-chain molecule.

This higher avidity of the pentamer compensates for the low affinity

TLS Online TPP Program

#Id: 9215

#Unit 11. Evolution and Behavior

Some factor determine Ne

1.Sex ratio.

2.Variation between individual in reproduction success.

3.Fluctuation in population size.

4.The age structure of the population.

5.Mating is random.

TLS Online TPP Program

#Id: 9216

#Unit 11. Evolution and Behavior

Ne = Male + Female  (when both are equal)

Ne = 4 × n(male) × n(female)/n(male)+n(female) 

(When both unequal Ne is smaller than then sum of both)

TLS Online TPP Program

#Id: 4685

#Unit 11. Evolution and Behavior

Social behaviour includes all kind of interaction between individuals of the same species.

TLS Online TPP Program

#Id: 4686

#Unit 11. Evolution and Behavior

Interactions are classified by how they affect the fitnesses of the two individuals.

TLS Online TPP Program

#Id: 4687

#Unit 11. Evolution and Behavior

Cooperation and selfishness both benefit the donor and therefore should be favoured by natural selection.

TLS Online TPP Program

#Id: 4688

#Unit 11. Evolution and Behavior

Evolution might favor traits that benefit the population or species, When one individual’s behavior benefits another, the behavior is cooperative.