The folding pathways of some proteins require two enzymes that catalyze isomerization reactions such as,

a) Peptide prolyl isomerase (PPI)  catalyzes the elimination of folding intermediates with inappropriate disulfide cross-links

b) Protein disulfide isomerase (PDI) enzyme that catalyzes the interchange, or shuffling, of disulfide bonds until the bonds of the native conformation are formed

c) Peptide prolyl cis-trans isomerase (PPI) catalyzes the interconversion of the cis and trans isomers of Proline residue peptide bonds

d) Peptide prolyl isomerase (PPI) can be a fast step in the folding of proteins that contain some Pro peptide bonds in the cis conformation

Which of the following combinations is correct about protein folding pathways?

TLS Online TPP Program

#Question id: 12285

#Unit 10. Ecological Principles

The principle of competitive exclusion states that

TLS Online TPP Program

#Question id: 12286

#Unit 10. Ecological Principles

Keystone predators can maintain species diversity in a community if they

TLS Online TPP Program

#Question id: 12287

#Unit 10. Ecological Principles

Food chains are sometimes short because

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#Question id: 3296

#Unit 10. Ecological Principles

Some beetles and flies have antler-like structures on their heads, much like male deer. The existence of antlers in beetle, fly, and deer species with strong male-male competition is an example of

TLS Online TPP Program

#Question id: 12349

#Unit 10. Ecological Principles

Males in a population differ in the time they spend displaying to females. A researcher hypothesizes that predators are responsible for these differences. Males display for longer durations when there are no predators in the vicinity and for shorter durations when there is a predator nearby. Which of the following study designs is the most appropriate test of this hypothesis?

TLS Online TPP Program

#Question id: 12347

#Unit 10. Ecological Principles

A team of conservation biologists, surveying a population of frogs on an island, captured and marked 312 individuals in the first sample. In a second sampling, 3 days later, the team caught 140 individuals of which 26 were previously marked. The total number of frogs on the island is estimated to be . (Use decimal notation, not fractions or percentage)