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#Question id: 1077

Would ID50 and LD50 necessarily be the same for a given virus? Why or why not?

#Unit 4. Cell Communication and Cell Signaling

  1. Yes, because the number of viruses that infect 50% of a test population should also kill 50% of that test population.

  2. No, because a virus may be highly infectious (very low ID50 value) but only marginally lethal (very high LD50 value). A prime example of this is the rhinovirus (common cold virus).

  3. No, because very few viruses are lethal, yet many are highly infectious. The two values should ALWAYS be different.

  4. Yes, because what we're actually describing here is infection/killing of individual CELLS, not of entire organisms. If a cell is infected, it will always be killed.

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TLS Online TPP Program

#Question id: 3983

#Unit 3. Fundamental Processes

Transcription of the lactose operon in E. coli is stimulated by:
TLS Online TPP Program

#Question id: 26557

#Unit 3. Fundamental Processes

The rate of mRNA deadenylation varies…A…… with the frequency of translation initiation for an mRNA the higher the frequency of initiation, the…B….. the rate of deadenylation
TLS Online TPP Program

#Question id: 12201

#Unit 6. System Physiology – Plant

ARF dependent signalling are regulated by auxin concenteration, given some condition followed;
I) In the absence of auxin
 II) In the presence of auxin
Find the statements that are correctly matched with given certain condition,
a)  AUX/IAA repressor proteins containing interaction domains similar to those found in the ARFs form heterodimers with the ARFs and thus repress transcriptional activation
b)  AUX/IAA repressors are recruited to the TIR1/AFB receptor complex and are tagged with ubiquitin for degradation by the 26S proteasome
c) ARFs form homodimers via conserved interaction domains and recruit chromatin remodelling
Which of the following combination is correct?
TLS Online TPP Program

#Question id: 16493

#Unit 12. Applied Biology

35S promoter sequences derived from cauliflower mosaic virus shows which type of expression.
TLS Online TPP Program

#Question id: 24545

#Unit 9. Diversity of Life Forms

Based on the phylogenetic tree, match the following taxon character with their accurate representation of relationship given in Column I and Column II;