Because migration and and other seasonal movements can affect the possibility of finding a mate, stresses, that could affect offspring survival(can vary with season), and also availability of thing that are available for the offspring.
Answer:
The Respiratory system allows the entry of oxygen into the body and releases Carbon Dioxide. The Oxygen travels across lung tissue into blood vessels and the blood carries the oxygen around the body. Thus the Respiratory and Circulatory systems work together in gas exchange which is vital in Homeostasis.
Chromosomes females have xx and males are xy
The main purpose of hemoglobin is the transport of OXYGEN and CARBON DIOXIDE
The set of characteristics provided by Audesirk and Audesirk are: Animals are multicellular. Animals are heterotrophic, obtaining their energy by consuming energy-releasing food substances. Animals typically reproduce sexually. Animals are made up of cells that do not have cell walls.
