Following statements are related to slow block to polyspermy in mammals.

A. A First slow block to polyspermy comes When the cortical granules fuse with the egg cell membrane, they release protein-digesting enzymes which is called as ovastacin that modify the zona pellucida proteins.

B. A second slow block to polyspermy comes from the so-called zinc spark, the release of billions of zinc ions that is induced by the entry of the first sperm, these released zinc ions are seen to bind to the egg cell membrane form a “zinc shield” that prevents further sperm entry.

C. A third slow block to polyspermy occurs at the level of the egg cell membrane and involves Juno.

Which of the following is incorrect?

TLS Online TPP Program

#Question id: 23190

#Unit 13. Methods in Biology

If we want to view live cells which microscopy can be best used for this?

1. Structured illumination microscopy

2. Phase contrast microscopy

3. Scanning electron microscopy

4. Cryoelectron microscopy

Which of the following option has correct combination?

TLS Online TPP Program

#Question id: 5044

#Unit 5. Developmental Biology

The cell might not look different from its nearest or most distant neighbors in the embryo and show no visible signs of differentiation, but its developmental fate has become restricted, the process known as-

TLS Online TPP Program

#Question id: 3002

#Unit 2. Cellular Organization

Cells are most sensitive to penicillin during which phase of the growth curve?

TLS Online TPP Program

#Question id: 23140

#Unit 13. Methods in Biology

What will be the resolution of a compound microscope where numerical aperture given is 1.5 at 240 wavelength of light?

TLS Online TPP Program

#Question id: 23358

#General Aptitude

Which of the following is a best method to control noise in the class room situation?