EARTH'S PROTECTIVE SHIELD. Earth is surrounded by invisible gases that form a thin protective blanket that we call the atmosphere. It contains the oxygen that we breath as well as other important gases such as nitrogen, carbon dioxide, water vapor, and ozone.
Physical anthropology, sometimes also called biological anthropology studies the biological features of human beings, such as morphological features, hair color, height, skin color etc. Besides that, it also studies the biological foundation of human behavior and adaptations of our species to the environment.
- developed from two separate eggs. Identical twins come from one zygote that splits into two embryos, while fraternal twins come from two separate eggs that are fertilized.
