EMS causes ethylation of the bases in DNA at the 7-N and the 6-O positions. When 7-ethylguanine is produced, it base-pairs with thymine to cause G:C → A:T transitions.

TLS Online TPP Program

#Id: 1663

#Unit 4. Cell Communication and Cell Signaling

Active Immunization

TLS Online TPP Program

#Id: 9143

#Unit 10. Ecological Principles

Host-Parasite Models

TLS Online TPP Program

#Id: 9141

#Unit 10. Ecological Principles

Mafia hypothesis – In Brood parasitism

Cuckoos or cowbirds check their host’s nests and destroy all eggs if their owner is not present. If the parasite egg has been removed, they destroy the host’s nest and kill or injure the nestlings.

TLS Online TPP Program

#Id: 8760

#Unit 1. Molecules and their Interaction Relevant to Biology

This is because hydrogen-bonding groups in an unfolded protein form hydrogen bonds with water molecules. Thus the contribution of a hydrogen bond to the stability of a native protein is the small difference in hydrogen bonding free energies between the native and unfolded states (−2 to 8 kJ ∙ mol−1)

TLS Online TPP Program

#Id: 4045

#Unit 2. Cellular Organization

G-bands are distinguished from interbands by their lower G-C content. This is a peculiar result. If there are 10 bands on a large chromosome with a total content of 100 megabases (Mb), this means that the chromosome is divided into regions of 5 Mb in length that alternate between low G-C (band) and high G-C (interband) content.

There is a tendency for genes to be enriched in the interband regions.