#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?
#Question id: 5106
#Unit 5. Developmental Biology
Given below are fate map of four organism and the pattern by which embryo undergo cleavage. Which of the following is right Combination?
#Question id: 13188
#Unit 10. Ecological Principles
The following figure is a model of seedling establishment as a function of distance from a parent tree. Initial seed density measures the number of seeds falling to the ground. Seed survivorship measures the proportion of seeds that survive to the adult stage at each distance
Which of the following factors is most likely to generate the seed survivorship curve shown?
#Question id: 11660
#Unit 10. Ecological Principles
Which of the following statements about the succession is true?
#Question id: 23247
#Unit 13. Methods in Biology