Extrinsic (death receptor–regulated) apoptosis pathway

binding of TNFα to TNFR1, a DD-containing death

receptor, recruits another two DD-containing

signaling molecules, TRADD and RIPK1

TLS Online TPP Program

#Id: 3968

#Unit 2. Cellular Organization

Each domain consists of -40 kilobases of DNA, or may be smaller, 10 kb each. About -400 domains in the E. coli genome. The ends of the domains appear to be randomly distributed instead of located at predetermined sites on the chromosome.

TLS Online TPP Program

#Id: 6289

#Unit 3. Fundamental Processes

This consensus sequence was derived by aligning 300 sequences known to function as s70 promoters and ascertaining the most common base found at each position in the –35 and –10 hexamers. That nucleotide is then chosen as the nucleotide of choice at that position in the consensus; its relative frequency and the frequencies with which the other three nucleotides occur at each position are portrayed in the graph. 

Note that there is no significant consensus among the 17–19 nucleotides that lie in the region between –35 and –10.

TLS Online TPP Program

#Id: 2350

#Unit 5. Developmental Biology

Planarian flatworms can reproduce asexually by binary fission, during which they split themselves in half.

TLS Online TPP Program

#Id: 6981

#Unit 5. Developmental Biology

A stem cell retains the ability to divide and re-create itself while also having the ability to generate progeny capable of specializing into a more differentiated cell type. 

TLS Online TPP Program

#Id: 10287

#Unit 4. Cell Communication and Cell Signaling

T-Cell - Cells leaving the thymus are functional, mature T cells expressing unique and specific T-cell receptors (TCRs) that are both tolerant to self and restricted to self-MHC.