TLS Online TPP Program

#Question id: 5647


Use the following information to answer the question. In order to test how sea urchin sperm bind to eggs, scientists isolated the egg receptor protein

that binds to the sperm acrosomal protein called bindin. Plastic beads were coated with egg receptor for bindin (ERB1) from eggs of the sea urchin Strongylocentrotus purpuratus, and then the beads mixed with sperm from S. purpuratus or from the related species, S. franciscanus. The researchers counted how many sperm were bound to each bead. The results are shown in the graph below. Treatments:

A: S. purpuratus sperm mixed with S. purpuratus ERB1 beads

B: S. purpuratus sperm mixed with beads containing no ERB1 protein

C: S. franciscanus sperm mixed with S. purpuratus ERB1 beads

D: S. franciscanus sperm mixed with beads containing no ERB1 protein

Based on the data in the graph, which of the following conclusions is supported?

#Unit 5. Developmental Biology
  1. Plastic beads will bind to sperm from both species of sea urchin.

  2. ERB1 prevents S. franciscanus sperm from binding the beads.

  3. Sperm from S. purpuratus bind to beads only if ERB1 is present.

  4. S. franciscanus and S. purpuratus are actually the same species.

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TLS Online TPP Program

#Question id: 4660

#Unit 3. Fundamental Processes

Two-component system regulating response to low Gln,

a) Glutamine dissociates from the sensor domain in the NtrB protein, leading to activation of a histidine kinase transmitter domain in NtrB

b) glutamine binds to a sensor domain of NtrB, causing a conformational change in the protein that inhibits its histidine kinase activity, the regulatory domain of NtrC blocks its DNA-binding domain from binding the glnA enhancers.

c) Activated transmitter domain of NtrB that transfers the γ-phosphate of ATP to a histidine residue (H), this phosphohistidine then transfers the phosphate to an aspartic acid residue (D) in the NtrC protein

d) This causes a conformational change in NtrC that unmasks the NtrC DNA-binding domain so that it can bind to the glnA enhancers

Which of the following combination is correct?

TLS Online TPP Program

#Question id: 4659

#Unit 3. Fundamental Processes

Many bacterial responses are controlled by two component regulatory systems. What will happen at the high concentration of glutamine and at the low concentration of glutamine?

a) At high concentrations glutamine binds to a sensor domain of NtrB conformational change in the protein that inhibits its histidine kinase activity

b) NtrC phosphorylation takes place causes a conformational change in NtrC that unmasks the NtrC DNA-binding domain so that it can bind to the glnA enhancers

c) At the same time, the regulatory domain of NtrC blocks its DNA-binding domain from binding the glnA enhancers

d) At low concentrations of glutamine dissociates from the sensor domain in the NtrB protein, leading to activation of a histidine kinase transmitter domain

Which of the following given combination is correct?

TLS Online TPP Program

#Question id: 4561

#Unit 3. Fundamental Processes

Which factor recruits capping enzyme?

TLS Online TPP Program

#Question id: 4560

#Unit 3. Fundamental Processes

TFIIH general is a general transcription factor phosphorylates the CTD multiple times on heptapeptide sequence such as

TLS Online TPP Program

#Question id: 4559

#Unit 3. Fundamental Processes

The 5’Cap is added to the eukaryotic nascent RNAs shortly after

TLS Online TPP Program

#Question id: 4558

#Unit 3. Fundamental Processes

Classes of RNA transcribed by the three eukaryotic nuclear RNA Polymerase;

                    Polymerase

             RNA Transcribed     

A. RNA polymerase I                   

i) tRNAs, 5S rRNA, snRNA, U6, 7S RNA

B. RNA polymerase II

ii) Pre-rRNA 28S, 18SrRNA,  5.8SrRNAs

C. RNA polymerase III

iii) mRNA, snRNAs, siRNAs, miRNAs

 Match the following correct combination given above combinations;