Sequential hermaphroditism Phenomenon in which the sex of an individual organism changes in the course of its lifetime.

TLS Online TPP Program

#Id: 4033

#Unit 2. Cellular Organization

In some cases, the various heterochromatic regions, especially those associated with centromeres, aggregate into a densely staining chromocenter.

The common form of heterochromatin that always remains heterochromatic is called constitutive heterochromatin. 

It is permanently condensed. 

It replicates late in S phase and has a reduced frequency of genetic recombination relative to euchromatic gene rich areas of the genome.

TLS Online TPP Program

#Id: 2307

#Unit 3. Fundamental Processes

During the transition to the open complex, the conformation of both the RNA polymerase and the DNA change. 

1) 90° bend in the DNA, which allows the template strand to approach the active site of the enzyme; 

2) strand opening of the promoter DNA between -11 and +3 with respect to the transcription start site; 

3) the promoter DNA scrunches into the active channel forming the transcription bubble; and 

4) closing of the jaws of the enzyme to encircle the section of the promoter downstream section of the transcription start site.

TLS Online TPP Program

#Id: 9108

#Unit 10. Ecological Principles

Antipredator Adaptations

TLS Online TPP Program

#Id: 869

#Unit 13. Methods in Biology

The efficiency of PCR can be calculated by using Y = X (1+ E)n X is number of templates, E is mean PCR efficiency, n is number is PCR cycle. 

 

TLS Online TPP Program

#Id: 10110

#Unit 4. Cell Communication and Cell Signaling

Ca2+-dependent cadherin- mediated adhesion also plays an important role in tight-junction formation, stability, and function