CORE LAB ![](GIFS/c-urchin.gif)
- What would happen if the sperm could not get into the egg?
- How do organisms develop from the size of a sperm and egg to an adult? What directs these changes?
- Why is there such a difference in the size of the egg and the sperm?
- Water currents in the ocean are much stronger than any sperm. How do sperm and egg find each other?
- Why do sea urchins have external fertilization? What are the adaptive advantages of external fertilization? What are the adaptive advantages of internal fertilization?
- What would happen if one cell was removed or damaged at the 2 cell, 4 cell, 8 cell stage?
- What would happen if the two cells were separated after the first cleavage and allowed to develop on their own?
- Why do cells with multiple chromosomes need the complex steps of mitosis to divide in comparison to the steps of binary fission in bacteria?