rNTPs are present at approximately 10-fold higher concentration in the cell, they are incorporated at a rate that is more than 1000-fold lower than dNTPs.

TLS Online TPP Program

#Id: 7222

#Unit 5. Developmental Biology

Allelic exclusion Most T cells fully rearrange and express a TCR chain from only one of their two TCR alleles.

TLS Online TPP Program

#Id: 3706

#Unit 2. Cellular Organization

When a genome contains a cluster of genes with related sequences, mispairing between nonallelic loci can cause unequal crossing over. This produces a deletion in one recombinant chromosome and a corresponding duplication in the other.

TLS Online TPP Program

#Id: 5492

#Unit 10. Ecological Principles

TLS Online TPP Program

#Id: 2833

#Unit 13. Methods in Biology

The peptide or protein (known as a ‘ tag’) can be placed at the N- or C-terminal ends and provides a means for the fusion protein to be selectively purified from the cell extract by affinity chromatography.

TLS Online TPP Program

#Id: 7412

#Unit 5. Developmental Biology

The maintenance of patterns is regulated by reciprocal interaction between neighboring cells: cells secreting Hedgehog protein activate wingless expression in their neighbors, and the Wingless protein signal, which is received by the cells that secreted Hedgehog, serves to maintain hedgehog (hh) expression