Class II presentation can occur with either live or replication-incompetent virus; protein synthesis inhibitors had no effect, indicating that new protein synthesis is not a necessary condition of class II presentation. 

TLS Online TPP Program

#Id: 9194

#XL - T Zoology

Hitchhiking

An important consequence of linkage disequilibrium is hitchhiking. This happens when an allele at  one locus spreads by natural selection acting on a second locus that is in linkage disequilibrium with  the first.

TLS Online TPP Program

#Id: 9195

#XL - T Zoology

Type of natural selection

1. Stabilized natural selection

2. Directional Natural selection

3. Disruptive Natural selection

4. Balance natural selection

TLS Online TPP Program

#Id: 9196

#XL - T Zoology

TLS Online TPP Program

#Id: 9197

#XL - T Zoology

Stabilized natural selection

Favor intermediate phenotype but eliminate lower and higher-grade phenotype

It introduced homogeneity in the population

Exp - clutch size of birds that lay too many or too few eggs per nest have lower fitness values than do those that lay an intermediate number of eggs

TLS Online TPP Program

#Id: 9198

#XL - T Zoology

TLS Online TPP Program

#Id: 9199

#XL - T Zoology

Directional Natural selection

Directional selection favors individuals at one extreme of a phenotypic distribution that have greater reproductive success in a particular environment.