Following statement regarding to acrosome reaction in sea urchin.

A. Activation of the acrosome reaction serves as a barrier to intraspecies fertilizations.

B. The acrosome reaction is initiated by sulfate-containing polysaccharides in the egg jelly that bind to specific receptors located directly above the acrosomal vesicle on the sperm cell membrane.

C. These polysaccharides are often highly species specific, but egg jelly factors from one species of sea urchin generally activate the acrosome reaction in closely related species.

D. The elevated Ca2+ level in a relatively basic cytoplasm triggers the fusion of the acrosomal membrane with the adjacent sperm cell membrane, releasing enzymes that can lyse a path through the egg jelly to the vitelline envelope.

Which of the following statements are correct?

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#Question id: 4480

#Unit 3. Fundamental Processes

The reason for TBP’s unorthodox recognition mechanism is

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#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: 8863

#Unit 9. Diversity of Life Forms

Which class of the phylum Cnidaria includes ʺjelliesʺ with rounded (as opposed to boxlike) medusae? 

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#Question id: 12839

#General Aptitude

The area of the shaded region in the figure given below is

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#Question id: 10781

#Unit 6. System Physiology – Plant

phytoecdysones, first isolated from___