What is the role of semaphorins and Eph ligands in development of the nervous system?

TLS Online TPP Program

#Question id: 15302

#Unit 5. Developmental Biology

FOXP1 is a transcription factor which stimulate the production of Oct4 and Nanog and establish pluripotency. Which of the following statements are correct regarding to the mechanism of alternative splicing of FOXP1. 

A. There are two isoforms of the FoxP1 protein, One is the product of an mRNA spliced to include a particular exon, 18b, while the other splicing variant carries exon 18a.

B. When alternative splicing generates a form including exon 18b in place of 18a, the resulting isoform (FOXP1-ES) binds to a different DNA sequence and thus controls expression of a different set of genes.

C. The protein encoded by the exon 18b– carrying mRNA is called FOXP1-ES it fails to stimulate expression of OCT4 and NANOG and instead actives genes that promote differentiation. 

D. The exon 18a– containing form encodes FOXP1 itself, and this has the opposite effect: this activates genes that promote dedifferentiation, and thus stimulates iPS cell formation.

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#Question id: 11655

#Unit 10. Ecological Principles

succession as proceeding to a distinct end point, each phase of succession shown in given diagram (A → D)

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#Question id: 11996

#Unit 10. Ecological Principles

Which of the following statements best describes the difference in approach to studying the environment by early naturalists compared to present-day ecologists?

TLS Online TPP Program

#Question id: 4150

#Unit 3. Fundamental Processes

Posttranslational glycosylation of proteins is inhibited specifically by:

TLS Online TPP Program

#Question id: 8696

#Unit 9. Diversity of Life Forms

There is some evidence that reptiles called cynodonts may have had whisker-like hairs around their mouths. If true, then hair is a shared ________.