Phytochrome B (PhyB) is probably the photoreceptor involved in shade detection and avoidance. This response allows many species to greatly increase their stem extension rate when they become shaded by competitors.

TLS Online TPP Program

#Id: 4668

#Unit 13. Methods in Biology

If the antibody preparation is polyclonal and has a range of affinities, Scatchard plot yields a curved line whose slope is constantly changing. The average affinity constant K0 can be calculated by determining the value of Ka when half of the binding sites are occupied (i.e., when r  1 in this example). In this graph, antiserum #3 has a higher affinity (K0  2.4  108) than antiserum #4 (K0  1.25  108)

TLS Online TPP Program

#Id: 4643

#Unit 13. Methods in Biology

Tritiated (3H) Thymidine uptake used to assess Cell Division based on radioactivity measurement by scintillation counting.

TLS Online TPP Program

#Id: 5026

#Unit 3. Fundamental Processes

The rate of bacterial growth is assessed by the doubling time, the period required for the number of cells to double.

The shorter the doubling time, the faster the bacteria are growing.

Escherichia coli growth rates can range from doubling times as fast as 18 minutes to slower than 180 minutes.

TLS Online TPP Program

#Id: 6810

#Unit 3. Fundamental Processes

RNA-dependent RNA polymerase (RdRP), an additional enzyme required in many cases of RNAi including centromeric silencing in fission yeast.

TLS Online TPP Program

#Id: 642

#Unit 3. Fundamental Processes

Alkylating agents are chemicals that donate alkyl groups to other molecules as nitrogen mustard, and methyl and ethyl methane sulfonate (MMS and EMS).