Tadpoles must undergo a major metamorphosis to become frogs. This change includes reabsorption of the tail, growth of limbs, calcification of the skeleton, increase in rhodopsin in the eye, development of lungs, change in hemoglobin structure, and reformation of the gut from the long gut of an herbivore to the short gut of a carnivore. Amazingly, all of these changes are induced by thyroxine. What is the most likely explanation for such a wide array of effects of thyroxine?

#Question id: 10803

#Unit 6. System Physiology – Plant

Which of the following are not consider as nitrogen-containing secondary metabolites?

#Question id: 10804

#Unit 6. System Physiology – Plant

Major types of alkaloids, their amino acid precursors, and well-known examples of each type;

Which of the following combination from the given table is correct?

#Question id: 10805

#Unit 6. System Physiology – Plant

Breakdown of cyanogenic glycosides in plants is a two-step enzymatic process, the enzymes necessary to hydrolyze the sugar and liberate HCN is

#Question id: 10806

#Unit 6. System Physiology – Plant

HCN is a fast-acting toxin that inhibits

#Question id: 10807

#Unit 6. System Physiology – Plant

Cyanogenic Glycosides and Glucosinolates are nitrogen containing secondary metabolites in plants. Following are some statements regarding the action of Cyanogenic Glycosides and Glucosinolates;

a) Cyanogenic Glycosides release the poison hydrogen cyanide by the action of enzyme known as Hydroxynitrile lyase

b) Release of the mustard-smelling volatiles from glucosinolates is catalyzed by a hydrolytic enzyme, called a thioglucosidase or myrosinase

c) substerate for Glycosidase is Cyanogenic glycoside and Thioglucosidase is Aglycone

d) Like cyanogenic glycosides, glucosinolates are stored in the intact plant separately from the enzymes that hydrolyze them, and they are brought into contact with these enzymes only when the plant is crushed

Which of the following combinations of above statement is true?

#Question id: 10808

#Unit 6. System Physiology – Plant

Many plants also contain unusual amino acids, called nonprotein amino acids, these Nonprotein amino acids are often very similar to common protein amino acids. Canavanine, for example, is a close analog of_____A______, and azetidine-2-carboxylic acid has a structure very much like that of_____B________.