In ValRS, the side chain of Asp 279 protrudes into the editing active site, where it hydrogen-bonds with the hydroxyl group of threonine. The isosteric (having the same shape) valine lacks this hydroxyl group and is thereby excluded from the editing pocket.

TLS Online TPP Program

#Id: 6976

#Unit 8. Inheritance Biology

TLS Online TPP Program

#Id: 6977

#Unit 8. Inheritance Biology

TLS Online TPP Program

#Id: 6978

#Unit 8. Inheritance Biology

HUMAN TRISOMIES

Trisomy 18 - Edward syndrome

Trisomy 13 - Patau syndrome. 

TLS Online TPP Program

#Id: 6979

#Unit 8. Inheritance Biology

Uniparental Disomy Inheritance of both chromosomes of a homologous pair from a single parent.  Many cases of uniparental disomy probably originate as trisomies. 

TLS Online TPP Program

#Id: 6980

#Unit 8. Inheritance Biology

Polyploidy 

Some organisms possess more than two sets of chromosomes—they are polyploid.  Allopolyploidy Condition in which the sets of chromosomes of a polyploid individual are derived from two or more species.  Autopolyploidy Condition in which all the sets of chromosomes of a polyploid individual are derived from a single species.

TLS Online TPP Program

#Id: 2140

#Unit 9. Diversity of Life Forms

Darwin have agreed that all animals with vertebrae form a single phylogenetic branch of species that share a common ancestor.