#Question id: 23502
#General Aptitude
#Question id: 1522
#Unit 4. Cell Communication and Cell Signaling
Conversion of a proto-oncogene into an oncogene, also called activation, generally involves a gain-of-function mutation. Following statements are regarding to the mechanisms that produce oncogenes from the corresponding proto-oncogenes.
A. A change in a single base pair in a proto-oncogene that results in a hyperactive or constitutively active protein product.
B. A chromosomal translocation that fuses two genes together to produce a hybrid gene encoding a chimeric protein whose activity, unlike that of the parent proteins, is permanently suppress.
C. A chromosomal translocation that brings a growth regulatory gene under the control of alternative enhancers that cause inappropriate expression of the gene.
D. Amplification of a DNA segment including a proto-oncogene so that numerous copies exist, leading to overproduction of the encoded protein.
Which of the following statements are correct?
#Question id: 10741
#Unit 10. Ecological Principles
My backyard borders a forest; when my backyard is well-maintained, where it and the forest meet is a(n)
#Question id: 2091
#Unit 2. Cellular Organization
Proteins can be attached to the phospholipid bilayer plasma membrane by covalently linked hydrocarbon groups. Which of the following mechanisms are not employed in this anchoring?
#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?