Practice Questions

  1. Home
  2. Free Resources
  3. Practice Questions
  4. 55441
TLS Online TPP Program

#Question id: 1532

For a particular microarray assay (DNA chip), cDNA has been made from the mRNAs of a dozen patients' breast tumor biopsies. Which of the following types of evidence will researchers be looking for in order to determine if the cells are cancerous?

#Unit 4. Cell Communication and Cell Signaling

  1. a particular gene that is amplified in all or most of the patient samples

  2. a pattern of fluorescence that indicates which cells are over proliferating

  3. a pattern shared among some or all of the samples that indicates gene expression differing from control samples

  4. a group of cDNAs that match those in non-breast cancer control samples from the same population

More Questions
TLS Online TPP Program

#Question id: 13000

#Unit 1. Molecules and their Interaction Relevant to Biology

Identify the correct statement regarding the structure
TLS Online TPP Program

#Question id: 12999

#Unit 1. Molecules and their Interaction Relevant to Biology

Proline and glycine both disturb the symmetry of α-helix which of the following are true regarding to these two amino acids
a) proline changes the orientation of hetropolymeric α-helix hence proline can be placed only as 1st amino acid residue near to C-terminus 
b) proline changes the orientation of polymeric α-helix hence proline can be placed only as 1st amino acid residue near to N-terminus
c) glycine disrupts the heteropolymeric α-helix by changing the helicity.
d) homopolymer of proline and glycine can form stable helix. 
TLS Online TPP Program

#Question id: 12998

#Unit 1. Molecules and their Interaction Relevant to Biology

Match with appropriate bonding pattern

Helix typeHydrogen bonding
a. α-helix1. n, n+3
b. 310 helix2. n, n+5
c. π helix3. n, n+4
TLS Online TPP Program

#Question id: 12997

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the given reason is correct to minimize the repulsion in an α-helix
a) positively charged amino acids are often found near the amino terminus of the helical segment
b) negatively charged amino acids are often found near the amino terminus of the helical segment
c) positively charged amino acids are often found near the C-terminus of the helical segment.
d) negatively charged amino acids are often found near the C-terminus of the helical segment.
TLS Online TPP Program

#Question id: 12996

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following is incorrect regarding to α-helix
a) In the α helix, the first four NH groups and last four CO groups will normally lack backbone  hydrogen bonds.
b) the length of an amino acid in α-helix reduced almost 3 times than linear structure.
c) the frequent occurrence of Pro and Gly residues favour α-helix formation.
d) dihedral (ϕ and ψ) angle should be close to -57 and -47.
TLS Online TPP Program

#Question id: 12995

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following constraints affect the stability α-helix, 
a) the intrinsic propensity of an amino acid residue to form an α-helix.
b) the interactions between R groups.
c) the bulkiness of adjacent R groups.
d) the occurrence of Pro and Gly residues.