Following are the statements related to mammalian chaemotaxis .
A. During chaemotaxis, the oocyte and its accompanying cumulus cells secrete molecules that attract only uncapacitated sperm toward the egg during the last stages of sperm migration.
B. These chaemotactic compound are hormone progesterone, which is made by the cumulus cells.
C. Progesterone has been shown to bind to a receptor that activates Ca2+ channels in the cell membrane of the sperm tail, leading to sperm hyperactivity and provides directional cue.
D. Cumulus cells also secrete a substance, CRISP1, that attracts sperm and hyperactivates them through CatSper channels similar as in sea urchins.
Which of  the following statement is incorrect?

TLS Online TPP Program

#Question id: 2203

#Unit 2. Cellular Organization

Parietal cells acidify the stomach contents while maintaining a neutral cytosolic pH by: 

a. exporting “excess” cytosolic OH– as HCO3–.
b. exchanging HCO3– for Cl–.
c. preserving electroneutrality by accompanying the movement of each Cl– ion into the stomach lumen by a K+.
d. the excess K+ ions pumped inward by the H+/K+ ATPase are returned to the stomach lumen, thus maintaining the normal intracellular K+ concentration.
Which of the following combination is correct?

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#Question id: 3879

#Unit 3. Fundamental Processes

Which of the following is not usually essential for the catalytic activity of ribozymes?

TLS Online TPP Program

#Question id: 31365

#Unit 1. Molecules and their Interaction Relevant to Biology

To purify ‘A’ from a mixture of these four proteins in a single step, using ion-exchange chromatography, what combination of buffer pH and ion-exchange resin would you select?

TLS Online TPP Program

#Question id: 21140

#Unit 12. Applied Biology

In nutrition limitation condition, the bacterial growth curve reaches onto the Idiophase. In this phase which mechanism is responsible for enhancing the secondary metabolite production?

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#Question id: 14503

#Unit 13. Methods in Biology

If 10 coins are tossed 100 times, how many times would you expect 7 coins to fall head upward ?