You are studying a new strain of E. coli that can utilize the disaccharide melibiose very efficiently. You find that utilization depends on the enzyme melibiase, which is encoded by the gene Mel1. Mel1 is not expressed unless melibiose is present in the growth medium. Next you isolate a mutation, designated MelB–, which gives uninducible melibiase activity. Mapping experiments show that MelB– is linked to Mel1. Using an F' factor that carries the chromosomal region surrounding Mel1, you perform the following genetic tests:

 

Describe the proposal for the type of regulatory functions affected by the MelB– mutation.

TLS Online TPP Program

#Question id: 29503

#Unit 6. System Physiology – Plant

Trichomes of nettles (Urtica dioica) have “cocktail” of secondary metabolites that can cause severe irritation of the skin of animals which are

a. Tartaric acid

b. Serotonin

c. Oxalic acid

d. Formic acid

Which of the following combination secondary metabolites is true

TLS Online TPP Program

#Question id: 29504

#Unit 6. System Physiology – Plant

Idioblasts cells are involved in the synthesis of

TLS Online TPP Program

#Question id: 29505

#Unit 6. System Physiology – Plant

Cicutoxin is produced by plant as constitutive chemical defenses which is

a. Produced by Hemlock (Cicuta sp.) 

b. Is  a polyacetylene

c. Involved in repolarization of neuronal action potentials

d. Involved in the suspension of all muscular activity

Which of the following is true regarding Cicutoxin

TLS Online TPP Program

#Question id: 29506

#Unit 6. System Physiology – Plant

The active principle in foxglove (Digitalis sp.) is cardinolide digitoxin  is a

a. cardiac glycoside 

b. that activate ATPase activity 

c. that inhibits ATPase activity 

d. can increase myocardial contraction

Which of the following is not true regarding digitoxin

TLS Online TPP Program

#Question id: 29507

#Unit 6. System Physiology – Plant

δ-Cadinene, Longifolene, Abietic Acid, Terpinolene, and -Pinene are the resin terpenoids that often contain cardiac glycosides produced by

TLS Online TPP Program

#Question id: 29508

#Unit 6. System Physiology – Plant

Conifer resin ducts produces different terpenes and resin acids which are released immediately upon damage by herbivores these are

Match them correctly with their example