#Question id: 7187
#Unit 5. Developmental Biology
Following statements regarding to feedback loops during limb development.
A. When the limb bud is relatively small, an initial positive feedback loop is established between Fgf10 produced in the mesoderm and Fgf8 produced in the ectoderm, promoting limb outgrowth.
B. As the limb bud grows, the ZPA is established, and another regulatory loop is created by inhibiting the BMP in mesoderm and maintain FGF expression.
C. In anterior region of the limb bud, Fgf8 positively regulates Etv4/5, which in turn repress Shh in this region, further reinforcing the posterior-to-anterior gradient of Shh from the ZPA.
D. In posterior region of the limb bud, Fgf8 positively regulates Etv4/5, which in turn repress Shh in this region, further reinforcing the posterior-to-anterior gradient of Shh from the ZPA.
Which of the following combinations are incorrect?
#Question id: 12491
#Unit 8. Inheritance Biology
#Question id: 861
#Unit 1. Molecules and their Interaction Relevant to Biology
Alexander Varshavsky discovered, the half-lives of many cytoplasmic proteins vary with the identities of their N-terminal residues via the so-called N-end rule:-
|
A. Destabilizing N-terminal residues Asp, Arg, Leu, Lys, and Phe have half-lives of |
i. Only 2 to 3 minutes, |
|
B. Stabilizing N-terminal residues Ala, Gly, Met, Ser, Thr, and Val have half-lives of |
ii. >10 hours in prokaryotes iii. >20 hours in eukaryotes. |
#Question id: 31238
#Unit 2. Cellular Organization
#Question id: 1626
#Unit 4. Cell Communication and Cell Signaling
The initial complement component activated by complement-fixing antibodies is: