Ramachandran plots can help increase the accuracy of models derived from x-ray crystallography data. The plot below was created by measuring phi, and psi for each amino acid residue in a 2.2 A resolution crystal structure. In the plot, which excludes Gly and Pro residues, selected residues (dots) are numbered 1 through 5.

Which of the following statements can be correctly stated for this plot in reference to selected residues?

A. Residues 1 and 3 are in either B sheets

B. residue 2 is in a right-handed a helix, and residue 4 is in a left-handed a helix.

C. If residue 5 were Gly, it might be in an acceptable position in the plot

TLS Online TPP Program

#Question id: 8923

#Part-A Aptitude & General Biotechnology

Which of these genetic processes may be most helpful in accounting for the Cambrian explosion?

TLS Online TPP Program

#Question id: 8923

#Part-B Specialized Branches in Biotechnology

Which of these genetic processes may be most helpful in accounting for the Cambrian explosion?

TLS Online TPP Program

#Question id: 8924

#Part-A Aptitude & General Biotechnology

Fossil evidence indicates that the following events occurred in what sequence, from earliest to most recent?

1. Protostomes invade terrestrial environments.

2. Cambrian explosion occurs.

3. Deuterostomes invade terrestrial environments.

4. Vertebrates become top predators in the seas.

TLS Online TPP Program

#Question id: 8924

#Part-B Specialized Branches in Biotechnology

Fossil evidence indicates that the following events occurred in what sequence, from earliest to most recent?

1. Protostomes invade terrestrial environments.

2. Cambrian explosion occurs.

3. Deuterostomes invade terrestrial environments.

4. Vertebrates become top predators in the seas.

TLS Online TPP Program

#Question id: 8925

#Part-A Aptitude & General Biotechnology

What is the probable sequence in which the following clades of animals originated, from earliest to most recent?

1. tetrapods

2. vertebrates

3. deuterostomes

4. amniotes

5. bilaterians

TLS Online TPP Program

#Question id: 8926

#Part-A Aptitude & General Biotechnology

Sponges and cnidarians are among the fossilized animals found in both the Ediacara Hills and the Burgess Shale from the Rocky Mountains of British Colombia. This observation requires that