The miRNAs used in RNAi are produced as large RNA primary transcripts called pri-miRNA that are self-complementary and can automatically fold into a double-strand hairpin structure.

TLS Online TPP Program

#Id: 9412

#Unit 11. Evolution and Behavior

Sexual dimorphism can evolve when selection favors the expression of a trait to be different in males and females. 

This situation is called sexually antagonistic selection, because an increase in the trait’s expression benefits one sex but harms the other.

TLS Online TPP Program

#Id: 9413

#Unit 11. Evolution and Behavior

An individual without gonads will leave no genes to the next generation. Gonads and genitalia are called primary sexual traits.

Secondary sexual traits, which differ between the sexes but do not play a direct role in reproduction.

TLS Online TPP Program

#Id: 9414

#Unit 11. Evolution and Behavior

TLS Online TPP Program

#Id: 9415

#Unit 11. Evolution and Behavior

Lack the form of sex based on meiosis that is familiar from animals and plants, they exchange genes using a variety of mechanisms that together are called “parasexuality”

TLS Online TPP Program

#Id: 9416

#Unit 11. Evolution and Behavior

A trait can evolve by sexual selection if it increases a male’s overall fitness, even if it decreases survival.

Exaggerated secondary sexual traits are favored by sexual selection because they increase male mating success.

TLS Online TPP Program

#Id: 9417

#Unit 11. Evolution and Behavior

The second part of Darwin’s hypothesis is that exaggerated secondary sexual traits decrease survival.