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TLS Online TPP Program

#Question id: 20324

What is the main difference between Gram positive and Gram-negative quorum sensing mechanism?

#Unit 4. Cell Communication and Cell Signaling
  1. Gram-negative bacteria use mainly peptides while Gram-positive bacteria use predominantly N-acyl homoserine lacton (AHL) molecules 
  2. Gram-negative bacteria use predominantly N-acyl homoserine lacton (AHL) molecules while Gram-positive bacteria use mainly peptides.
  3. Gram-negative bacteria use mainly peptides while Gram-positive bacteria use predominantly autoinducer-1, AI-1.
  4. Gram-positive bacteria is more resistance to antibiotics than Gram- negative.
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TLS Online TPP Program

#Question id: 12183

#Unit 1. Molecules and their Interaction Relevant to Biology

Following statements are regarding to regulation of S phase and mitotic cyclin levels in budding yeast.
A. In late anaphase, the anaphase-promoting complex (APC/C) ubiquitinylates S phase and mitotic cyclins.
B. In late anaphase, the anaphase-promoting complex (APC/C) phosphorylates S phase and mitotic cyclins.
C. During exit from mitosis and G1, Cdh1 is dephosphorylated and active; during S phase and mitosis, Cdh1 is phosphorylated and dissociates from APC/C, and APC/C becomes inactive.
D. During exit from mitosis and G1, Cdh1 is phosphorylated and active; during S phase and mitosis, Cdh1 is dephosphorylated and dissociates from APC/C, and APC/C becomes inactive.
E. The G1/S phase CDKs, which themselves are not APC/CCdh1 substrates, phosphorylate Cdh1 at the G1–S phase transition.
F. The G1/S phase CDKs, which themselves are not APC/CCdh1 substrates, ubiquitinylates Cdh1 at the G1–S phase transition.
Which of the following combination is correct?
TLS Online TPP Program

#Question id: 4164

#Unit 3. Fundamental Processes

Which help cells avoid mis-insertion of amino acids in protein synthesis?
TLS Online TPP Program

#Question id: 14707

#Unit 5. Developmental Biology

Which of the following organ belongs to the internal layer of gastrula?
TLS Online TPP Program

#Question id: 3351

#Unit 11. Evolution and Behavior

In pre-industrial period in England, most peppered moths had light coloration. During industrial revolution, many lichens died out and trees became blackened by soot from factories and interestingly, dark colored moths were predominantly seen. Which of the following observation is incorrect about above selection?
TLS Online TPP Program

#Question id: 15194

#Unit 8. Inheritance Biology

 Genes that control coat color in mammals represent some of the best early examples of genes with multiple alleles exhibiting different phenotypes. A classic example is the C gene in hamsters. Three of the known alleles of this gene are C, ca and ck. Each supplies a different amount of black pigment to the coat hair. The phenotypes of three different homozygous strains are as follows.

would mate the true-breeding  ca ca  hamsters to the true-breeding ck ck  hamsters to produce heterozygous  ca and ck  F1 progeny,  the F1 progeny cack  hamsters self fertilized, From the fraction of F2 progeny that have the wild type black phenotype, 

Crosses and their interpretation that would have allowed geneticists to come to the conclusion that ca and ck were likely to be alleles of the different gene. 
What will be the ratio of F2 hamster;