Answer:
Simple diffusion is when the particles travel through the cell and facilitated diffusion is when the molecules travel through the cell.
Turtles can breath in and out of water. Fish only can breath in water.
Answer:
3) Fertilization membrane.
Explanation:
When sperm cell fertilizes an egg cell, signal transdution occurs which causes fertilization membrane to be formed. Ovum thickens and hardens the vetelline membrane causing separation and prevents multiple fertilization by the spermatozoon.
An antigen causes the body to make antibodies.
