Hormonal interactions contribute to plant–insect herbivore interactions such as— ethylene, salicylic acid, and jasmonic acid. In particular, ethylene appears to play an important role in this context, what will be the effect of ethylene when is applied alone and when is applied with other amino acids?

a) ethylene applied together with JA it seems to reduces defense responses

b) Ethylene appears to applied alone to plants, ethylene has little effect on defense-related gene activation

c) when ethylene applied together with JA it seems to enhance JA responses or defense responses are significantly increased

d) Ethylene appears to applied alone to plants, ethylene has more effect on defense-related gene activation

Which of the following combination is correct about ethylene effects?

#Question id: 4089

#Unit 3. Fundamental Processes

An investigator incubates an unprocessed RNA molecule containing an intron in an extract absent of any protein. Correct splicing of the RNA is observed, but only when guanosine is present. What can the investigator conclude about the RNA molecule?

a. It contains a ribozyme. 

b. Self-splicing has occurred.

c. It contains a group II intron.

d. It contains a group I intron.

#Question id: 4090

#Unit 3. Fundamental Processes

Tryptophan synthesis can be controlled by a process called attenuation in which the levels of tryptophan in the cell control translation by

#Question id: 4091

#Unit 3. Fundamental Processes

To avoid being degraded by nuclear exonucleases, nascent transcripts, pre-mRNA-processing intermediates, and mature mRNAs in the nucleus must have their ends protected. Which of the following mechanism are present in the cell to protect mRNA from degradation?

I. The 5′ cap is protected because it is bound by a heterodimeric nuclear cap-binding complex (CBC), which protects it from 5′ exonucleases and also functions in export of the mRNA to the cytoplasm.

II. 5’-5’ phosphodiester bond in the cap of mRNA plays crucial role in protection

III. The 3′ end of a nascent transcript lies within the RNA polymerase and is thus inaccessible to exonucleases 

#Question id: 4092

#Unit 3. Fundamental Processes

An experimental setup provided the assay for identifying factors that facilitate transcription in the presence of chromatin. A factor called FACT (facilitates chromatin transcription) functions as

#Question id: 4093

#Unit 3. Fundamental Processes

Which of the following processes is NOT an example of allosteric regulation? 

#Question id: 4094

#Unit 3. Fundamental Processes

The accompanying figure depicts the map of a part of E. coli genome harboring the lac operon.

 lac mRNA would hybridize to which of the following DNA?

1) lac I; 2) lac 0; 3) lac Z; 4) lac Y; 5) lac A