Which subunit of the E. coli core RNA polymerase (a2bbʹw) contributes to DNA binding?

A) a                 B) b                 C) bʹ                D) w

#Question id: 5672

#Unit 5. Developmental Biology

Following statements are regarding to recognition of sperm by mammalian zona pellucida.

A. Sperm that have undergone the acrosome reaction bind directly to zona protein ZP2 and begin making a channel toward the oocyte.

B. Sperm with an intact acrosome bind to ZP2; they undergo the acrosome reaction on the zona pellucida and then transfer their binding to ZP3.

C. When a sperm reaches the oocyte and fuses with it, the cortical granules release proteins that digest portions of ZP2 and ZP3, making them nonfunctional and prevent polyspermy.

D. When a sperm reaches the oocyte and fuses with it, the cortical granules release proteins that digest ZP3 only, not ZP2 because ZP2 involve in the process of slow block to polyspermy.

Which of the above statements are correct?

#Question id: 20320

#Unit 4. Cell Communication and Cell Signaling

#Question id: 7089

#Unit 5. Developmental Biology

The ecdysozoans are:

#Question id: 28529

#Unit 5. Developmental Biology

FACKEL (FK) encodes an enzyme which function as a critical for pattern formation during embryogenesis, such enzyme is know as___ 

#Question id: 28525

#Unit 5. Developmental Biology

At which stage of plant development, Cell elongation and cellular differentiation processes occur throughout the embryonic axis?