#Question id: 16955
#Unit 4. Cell Communication and Cell Signaling
#Question id: 5076
#Unit 5. Developmental Biology
Homeotic genes are responsible for:
#Question id: 880
#Unit 1. Molecules and their Interaction Relevant to Biology
The classic work of Christian Anfinsen in the 1950s on the enzyme ribonuclease revealed the relation between the amino acid sequence of a protein and its conformation. Ribonuclease is a single polypeptide chain consisting of 124 amino acid residues cross-linked by four disulfide bonds. Anfinsen’s plan was to destroy the three-dimensional structure of the enzyme and to then determine what conditions were required to restore the structure.
The critical observation of Anfinsen that the denatured ribonuclease, freed of urea and b -mercaptoethanol by dialysis;
I. The sulfhydryl groups of the denatured enzyme became reduced by air, and the enzyme spontaneously refolded into a catalytically active form.
II. These experiments showed that the information needed to specify the catalytically active structure of ribonuclease is contained in its amino acid sequence.
III. The 105 wrong pairings have been picturesquely termed “scrambled” ribonuclease.
IV. He found that scrambled ribonuclease spontaneously converted into fully active, native ribonuclease when trace amounts of b -mercaptoethanol were added to an aqueous solution of the protein.
Choose incorrect options;
#Question id: 10857
#Unit 10. Ecological Principles
Cowbirds never make nests, never incubate their eggs, and never care for their young. Instead they lay their eggs in the nests of host species, which either reject the egg or care for it and the young that hatches as their own. The cowbird is an example of a(n)
#Question id: 6984
#Unit 5. Developmental Biology
Which of the following genes is unlikely to be involved in preaxial polydactyly in mice?