Which of the following statement is true about zebrafish gastrulation?
1
The posterior portion of the embryonic shield establishes the primary dorsal-ventral axis in the zebrafish.
2
The nieuwkoop Center is established when the cortical rotation of yolk cytoplasm occurs immediately after fertilization.
3
Active cell movement of blastoderm cell over the yolk mass surface is referred to as epiboly and is part of gastrulation.
4
The first cleavage division of a fertilized zebrafish egg completely cleaves the egg and establishing a blastopore lip.