Proximate causes - The subject of cell biology, neurobiology, and many other biological disciplines

Ultimate causes - Their historical causes, especially the action of natural selection

TLS Online TPP Program

#Id: 2646

#Unit 13. Methods in Biology

A G-less cassette, or stretch of nucleotides lacking guanines in the nontemplate strand, is inserted just downstream of the promoter. This template is transcribed in vitro with CTP, ATP, and UTP, one of which is labeled, but no GTP.

TLS Online TPP Program

#Id: 2254

#Unit 11. Evolution and Behavior

Frequency-dependent selection,

1.    Positive frequency

2.    Negative frequency

TLS Online TPP Program

#Id: 3594

#Unit 3. Fundamental Processes

In 1961 Marshall Nirenberg and Heinrich Matthaei reported the first breakthrough in reading nucleotide codon in amino acid frame.

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: 6024

#Unit 3. Fundamental Processes

DNA polymerase a is unusual because it has the ability to initiate a new strand. It is used to initiate both the leading and lagging strands. 

The enzyme exists as a complex consisting of a 180-kD catalytic (DNA polymerase) subunit, which is associated with three other subunits: the B subunit that appears necessary for assembly, and two small subunits that provide the primase (RNA polymerase) activity.  It has dual capacity to prime and extend chains, this complex is often called pol a/primase.