In the early stages the embryos of four different species will look the same .For example, fish embryos and human embryos both have gill slits. In fish they develop into gills, but in humans they disappear before birth. That what makes them different.
A warm air does always rise and cold air falls
i believe the answer to be B
Answer:
Excretion is a process by which metabolic waste is eliminated from an organism. In vertebrates this is primarily carried out by the lungs, kidneys and skin. This is in contrast with secretion, where the substance may have specific tasks after leaving the cell. Excretion is an essential process in all forms of life.
Explanation:
can u mark me brainlyest
