Photoreactivation; Ultraviolet irradiation causes formation of thymine dimers. Upon exposure to light, DNA photolyase breaks the ring formed between the dimers to restore the two thymine residues.

TLS Online TPP Program

#Id: 2176

#Unit 11. Evolution and Behavior

Positive Selection: The Spread of Beneficial Mutations

TLS Online TPP Program

#Id: 2605

#Unit 13. Methods in Biology

Many different alleles are present in a population, but each person has only two alleles of any given SSR locus.

TLS Online TPP Program

#Id: 1757

#Unit 4. Cell Communication and Cell Signaling

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: 4240

#Unit 12. Applied Biology

Most cells are anchorage dependent and must be cultured while attached to a solid or semi-solid substrate (adherent or monolayer culture), while others can be grown floating in the culture medium (suspension culture). 

TLS Online TPP Program

#Id: 9202

#Unit 11. Evolution and Behavior

Disruptive Natural selection

Disruptive selection favors the survival of individuals at both extremes of a range, rather than the  intermediate.

Increase variance in the population because select those phenotype which are away from mean.

It maintain balance polymorphism and maximum selection coefficient value.