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TLS Online TPP Program

#Question id: 1262

Although MAP kinase is often activated in multicellular animals by RTKs or cytokine receptors, signaling from other receptors can activate MAP kinase in other eukaryotic cells. we consider the mating pathway in the yeast S. cerevisiae, a well-studied example of a MAP kinase cascade linked to G protein–coupled receptors (GPCRs). Which of the following statement is incorrect?

#Unit 4. Cell Communication and Cell Signaling

  1. An a haploid cell secretes the a mating factor and has GPCRs for the α factor on its cell surface; an α cell secretes the α factor and has GPCRs for the a factor. Thus each type of cell recognizes the mating factor produced by the opposite type.

  2. Ligand binding and dissociation of the G protein subunits, the membrane-tethered Gβγ subunit binds the Ste5 scaffold to the plasma membrane.

  3. Gβγ also activates Cdc24, a GAP for the Ras-like protein Cdc42; the active, GTP-bound Cdc42, in turn, binds to and activates the Ste20 kinase.

  4. Ste20 then phosphorylates and activates Ste11, which is analogous to Raf and other mammalian MEK kinase (MEKK) proteins. Ste20 thus serves as a MAPKKK kinase.

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TLS Online TPP Program

#Question id: 7289

#Unit 5. Developmental Biology

The following scheme shows the flowering status of a plant species and the photoperiodism. Which of the following conclusions is most appropriate?
TLS Online TPP Program

#Question id: 7289

#Unit 1. Molecules and their Interaction Relevant to Biology

The following scheme shows the flowering status of a plant species and the photoperiodism. Which of the following conclusions is most appropriate?
TLS Online TPP Program

#Question id: 7290

#Unit 5. Developmental Biology

Following figure regarding to regulatory network in the Arabidopsis shoot meristem stem-cell niche.

A. The transcription factor WUS is synthesized in the cell A and moves via plasmodesmata into cell B, where one of its functions is to induce expression of the CLV3.

B. The transcription factor CLV3 is synthesized in the cell A and moves via plasmodesmata into cell B, where one of its functions is to induce expression of the WUS.

C. Secreted CLV3 protein from cell B binds to the receptor protein kinase on the surface of cell A; there, it activates a signal that represses WUS transcription.

D. Secreted WUS protein from cell B binds to the receptor protein kinase on the surface of cell A; there, it activates a signal that represses CLV3 transcription.

Which of the following combination is correct?
TLS Online TPP Program

#Question id: 7291

#Unit 5. Developmental Biology

Five different genes are known to specify floral organ identity in Arabidopsis: APETALA1 (AP1), APETALA2 (AP2), APETALA3 (AP3), PISTILLATA (PI), and AGAMOUS (AG).

Which one of the following statement is incorrect?
TLS Online TPP Program

#Question id: 7292

#Unit 5. Developmental Biology

How is plant cell cytokinesis different from animal cell cytokinesis?
TLS Online TPP Program

#Question id: 7293

#Unit 5. Developmental Biology

In agamous mutant (flower within flower phenotype) which of the following statements is valid?