The process of development is very complex with lots of possibilities for things to go wrong. What would happen if:
- the sperm could not get into the egg?
- the male and female pronuclei did not fuse?
- DNA synthesis did not occur?
- the centrosome did not align the chromosomes properly at metaphase?
- the actual division was not competed or happened at the wrong location?
- one cell was removed or damaged at the 2 cell, 4 cell, 8 cell stage?
- at the two cell stage the two cells were separated and allowed to develop on their own? at the 4 cell stage?
- hatching did not occur?
- gastrulation went out instead of in?
- skeleton failed to form in the pluteus?
Further questions for thought:
- Why do cells with multiple chromosomes need the complex steps of mitosis to divide in comparison to the steps of binary fission in bacteria?
- What are the adaptive advantages of external fertilization? What are the adaptive advantages of internal fertilization?
- What are the adaptive advantages of external development? What are the adaptive advantages of internal development?