#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: 5661
#Unit 5. Developmental Biology
Following statements regarding to the embryogenesis in A. thaliana.
A. The first zygotic division is unequal, with the basal cell larger than the apical cell. The basal cell divides to give rise to the suspensor. The apical cell divides vertically to form a two-celled proembryo, which will give rise to the rest of the embryo.
B. The top most suspensor cell is recruited into the embryo, where it is known as the hypophysis, and contributes to the embryonic root meristem and root cap.
C. The next two divisions produce an eight-cell octant-stage embryo, which develops into a heart-stage embryo of around 32 cells
D. The embryo elongates and the cotyledons start to develop as wing-like structures at one end, while an embryonic root forms at the other. This stage is known as the globular stage.
Which of the following statements are correct?
#Question id: 9277
#Unit 6. System Physiology – Plant
The light energy absorbed by the carotenoids is transferred to chlorophyll for photosynthesis; because of this role they are called
#Question id: 3412
#Unit 11. Evolution and Behavior
What will be frequency of inbreeding coefficient between G and H?
#Question id: 23193
#Unit 13. Methods in Biology