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TLS Online TPP Program

#Question id: 2677

Why is the transcription of structural genes of the trp operon turned off in the presence of tryptophan?

#Unit 2. Cellular Organization

  1. Tryptophan is the repressor that binds to the operator, preventing transcription.

  2. The structural genes are used to make tryptophan, which would not be needed if tryptophan is available.

  3. Tryptophan has no effect on the transcription of the structural genes.

  4. Tryptophan RNA polymerase from finding the promoter of the trp operon, preventing structural gene transcription.

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TLS Online TPP Program

#Question id: 5087

#Unit 5. Developmental Biology

The outer-to-inner sequence of tissue layers in a post-gastrulation vertebrate embryo is ________.
TLS Online TPP Program

#Question id: 10772

#Unit 8. Inheritance Biology

In an experiment plant RR round genotype have 100 seeds. In F1 generation 70 seeds are round and 30 seeds are wrinkled. So what will be
the penetrance value for round seeds?
TLS Online TPP Program

#Question id: 31314

#Unit 6. System Physiology – Plant

Pyruvate is precursor of which secondary metabolite biosynthetic pathway
TLS Online TPP Program

#Question id: 1083

#Unit 4. Cell Communication and Cell Signaling

 When a neuron responds to a particular neurotransmitter by opening gated ion channels, the neurotransmitter is serving as which part of the signal pathway?
TLS Online TPP Program

#Question id: 27921

#Unit 11. Evolution and Behavior

Who hypothesized that different organisms originated separately by spontaneous generation from nonliving matter ?