Typically as cells grow, their increase in volume outpaces their increase in surface area, and continued survival requires undergoing asexual reproduction to reestablish a healthy surface area to volume ratio. Thus, which of these is least likely to contribute to the ability of a single-celled foraminiferan to grow to a diameter of several centimeters?

#Question id: 5006

#Unit 11. Evolution and Behavior

The oxygen revolution changed Earthʹs environment dramatically. Which of the following adaptations took advantage of the presence of free oxygen in the oceans and atmosphere?

#Question id: 13233

#Unit 6. System Physiology – Plant

#Question id: 10451

#Unit 6. System Physiology – Plant

Which induction is responsible for “uncages” the kinase domain of phototropin and leads to autophosphorylation

#Question id: 4187

#Unit 3. Fundamental Processes

Prokaryotic mRNA molecules that contain several coding regions that encode several polypeptides are __.

#Question id: 1251

#Unit 4. Cell Communication and Cell Signaling

 Following statements are regarding to receptor serine kinases.

A. The two serines in each Smad3 that were phosphorylated by the RI receptor kinase bind to phosphoserine-binding sites in the MH1 domains of a Smad3 or a Smad4, forming a stable complex containing two molecules of phosphorylated Smad3 (or Smad2) and one molecule of the co-Smad (Smad4).

B. The bound importin then mediates translocation of the heteromeric R-Smad/co-Smad complex into the nucleus.

C. After importin dissociates inside the nucleus, the Smad3/Smad4 (or Smad2/Smad4) complex binds to other transcription factors to activate transcription of specific target genes.

D. Transcription of the PAI-1 gene requires formation of a complex of the transcription factor TFE3 with the R-Smad/co-Smad (Smad3/Smad4) complex and binding of all these proteins to specific sequences within the regulatory region of the PAI-1 gene.

E. Within the nucleus, R-Smads are further modified by phosphorylation of their linker domains, monoubiquitinylation of their MH1 domains, acetylation of their MH2 domains, and dephosphorylation of the C-terminal serines by nuclear phosphatases.

Which of the following combination is incorrect?