Mutation and natural selection act as opposing forces on detrimental alleles.

TLS Online TPP Program

#Id: 6497

#Unit 3. Fundamental Processes

On a linear template, ATP hydrolysis, TFIIE, and the helicase activity of TFIIH (provided by the XPB and XPD subunits) are required for polymerase movement. This requirement is bypassed with a supercoiled template. This suggests that TFIIE and TFIIH are required to melt DNA to allow polymerase movement to begin. To extend elongation into the transcription unit, a kinase complex called P-TEFb is required. P-TEFb contains the CDK9

kinase, which is a member of the kinase family that controls the cell cycle. P-TEFb acts on the CTD to phosphorylate it further on serine 2 of the heptapeptide repeat.

TLS Online TPP Program

#Id: 7085

#Unit 3. Fundamental Processes

TLS Online TPP Program

#Id: 3800

#Unit 5. Developmental Biology

Dictyostelium can utilize one of three survival strategies when food starvation-

Microcyst formation, favoured in dark & wet conditions, or ammonia levels are high.

Zygote formation, favoured in dark & wet conditions, & is triggered by ethylene produced by the cells. 

Cell aggregation & differentiation

TLS Online TPP Program

#Id: 1466

#Unit 4. Cell Communication and Cell Signaling

Nonclassical cadherins include proteins:

• Protocadherins found in the brain

• Desmocollins and desmogleins that form desmosomes

TLS Online TPP Program

#Id: 7052

#Unit 11. Evolution and Behavior

Hamilton’s rule:  It states that an allele that causes an altruistic behavior will spread if the following condition is met (rb>C)