Practice Questions

  1. Home
  2. Free Resources
  3. Practice Questions
  4. 55843
TLS Online TPP Program

#Question id: 13214

The stomata will open less or even remain closed on a sunny morning when

#Unit 6. System Physiology – Plant
  1. soil water is abundant, plant dehydration takes place
  2. soil water is less abundant, the solar radiation incident on the leaf favors high photosynthetic activity, the demand for CO2 inside the leaf is large
  3. soil water is less abundant, plants avoid dehydration
  4. soil water is abundant,  stomatal pores allows the diffusional resistance for water loss from leaves
More Questions
TLS Online TPP Program

#Question id: 733

#Unit 1. Molecules and their Interaction Relevant to Biology

Which one of the statements on protein conformation, detailed below is INCORRECT?
TLS Online TPP Program

#Question id: 732

#Unit 1. Molecules and their Interaction Relevant to Biology

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: 731

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following structure is mentioned in the given Ramachandran plot
TLS Online TPP Program

#Question id: 729

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following is correct about the collagen triple-helix domain

a. is rich in glycine.                             b. is rich in proline.

c. is rich in hydroxyproline.                d. is an alpha helix.
TLS Online TPP Program

#Question id: 728

#Unit 1. Molecules and their Interaction Relevant to Biology

Match the following tile peaks with corresponding circular dichroism spectra

A. Alpha helixI. negative bands at 222 nm and 208 nm and a positive one at 190 nm.
B. Beta sheetII. negative band at 218 nm and a positive one at 196 nm.
C. Random coilIII. positive band at 212 nm and a negative one around 195 nm.
TLS Online TPP Program

#Question id: 727

#Unit 1. Molecules and their Interaction Relevant to Biology

26-residue peptide composed of alanine and leucine shows a circular dichroism (CD) spectrum characteristic of α-helix at 50°C in 5 mM phosphate buffer at pH 7.4. When the peptide solution is cooled gradually to 25°C, and the CD spectra are recorded at different temperatures, the most likely observation will be that