Several hypotheses explain the existence of monogamy.

1. Mate-guarding hypothesis, a male stays with a female to protect her from being fertilized by other males.

2. The male assistance hypothesis maintains that males remain with females to help them rear their offspring.

3. The female-enforced monogamy, females stop their male partners from being polygynous.

TLS Online TPP Program

#Id: 10380

#XL - Q Biochemistry

IFN- ¥ has been shown to induce expression of the class II transcriptional activator (CIITA). 

TLS Online TPP Program

#Id: 10329

#XL - Q Biochemistry

Binding of the extracellular TCR domain to a MHC-peptide complex triggers activation of ZAP70 protein tyrosine kinases attached to the cytosolic domains of the two adjacent ζ chains. 

TLS Online TPP Program

#Id: 7876

#XL - Q Biochemistry

Mitochondria diameter of 0.5–1μm, dynamic, moving about the cell, constantly changing shape, dividing, & fusing.

TLS Online TPP Program

#Id: 9487

#XL - R Botany

Biotrophs are Specialised (‘obligate’) pathogens

Possess appressoria or haustoria

Narrow host range

Controlled by salicylate-dependent host-defence pathways

TLS Online TPP Program

#Id: 4308

#XL - T Zoology

Haldane’s rule: hybrid sterility or hybrid inviability is often limited to the heterogametic sex. (The heterogametic sex is the one with two different sex chromosomes, while the homogametic sex has two sex chromosomes of the same type).