TLS Online TPP Program

#Question id: 14838


Sequence of amphibian lens induction postulated by experiments on embryos of the frog Xenopus laevis ; EXCEPT

#Unit 5. Developmental Biology
  1. Unidentified inducers (possibly from the foregut endoderm and cardiac mesoderm) cause the synthesis of the Otx2 transcription factor in the head ectoderm during the late neurula stage.
  2. As the neural folds rise, inducers from the anterior neural plate (including the region that will form the retina) induce Pax6 expression in the anterior ectoderm that can form lens tissue.
  3. As the neural folds rise, inducers from the anterior neural plate (including the region that will form the retina) induce Pax6 expression in the anterior ectoderm that can form lens tissue.
  4. The optic vesicle secretes BMP and FGF family paracrine factors, which induce the synthesis of the Sox transcription factors and initiate observable lens formation

More Questions
TLS Online TPP Program

#Question id: 4273

#Unit 3. Fundamental Processes

80S initiation complex includes

TLS Online TPP Program

#Question id: 4274

#Unit 3. Fundamental Processes

One mechanism that contributes to the fidelity of codon recognition involves the 16S rRNA other than initiation. Which of the following statements are correct in this phenomenon?

A. Codon recognition involves two adjacent uracil residues in the 16S rRNA component

B. The adjacent residues in the 16S rRNA do not discriminate between G:C or A:U base pairs and recognize either as correct

C. Even a single mismatch in the codon–anticodon base pairing alters the position of EF-Tu, reducing its ability to interact with the factor-binding center 16s rRNA, leads to a dramatic reduction in EF-Tu GTPase activity

D. Pyrophasphatic editing is key mechanism to ensure fidelity

TLS Online TPP Program

#Question id: 4275

#Unit 3. Fundamental Processes

CCA-adding enzymes add a specific sequence without a template because

TLS Online TPP Program

#Question id: 4276

#Unit 3. Fundamental Processes

Which of the following post-translational modifications of proteins occur(s) in the lumen of the endoplasmic reticulum?

a. glycosylation                       b. formation of disulfide bonds

c. conformational folding and formation of quaternary structure

d. proteolytic cleavage                        e. aldol condensation of sugars

TLS Online TPP Program

#Question id: 4277

#Unit 3. Fundamental Processes

N-linked oligosaccharides in glycoproteins

TLS Online TPP Program

#Question id: 4278

#Unit 3. Fundamental Processes

N-terminal sequences usually function as targeting signals for protein transport into

a. the nucleus.             b. peroxisomes.                       c. chloroplasts.

d. the rough endoplasmic reticulum.   e. mitochondria.