Earth Science: Biology – Humans – Skeletal system: Bones Humans have a bony skeleton with movable joints. Several key adaptations provide strength and flexibility and enable human beings to walk upright. The adult human skeleton has about 206 individual bones and several important functions. It supports the body and protects the inner organs. For example, … Read more
Earth Science: Anatomy – Respiration and the lungs The lungs are vital organs in the human body that provide oxygen required for most metabolic processes. Lungs also discharge carbon dioxide (CO,), a metabolic waste product, which would otherwise poison the body. The lungs are made up of two main components: the left and the right … Read more
Discovery Science: Earth Biology – Humans Anatomy The form, location, and structure of cells, tissues, organs, and whole body parts is nearly identical in all human beings. The spine and the bones give the body its stability, muscles and joints provide for its flexibility, and the blood circulation supplies all the tissues and internal organs … Read more
Earth Science: Human – Puberty and Aging Puberty and aging are both phases of transition in the human life cycle: during puberty, the body reaches sexual maturity, while aging leads to a gradual loss of life functions. Girls will normally experience puberty, and the associated changes in their body, mind, and emotional state, at the … Read more
Earth Science: Biology – Humans – Embryogenesis A developing child goes through several phases as an embryo. Embryogenesis begins with the first cell divisions while the zygote travels to the uterus where the embryonic and fetal phases then occur. Once an egg cell has been fertilized, it travels as a zygote through the fallopian tube … Read more
Earth Science: Humans – Reproduction When humans reproduce, two differentiated germ cells (egg and sperm) merge. A new person develops from the fertilized egg-a process that takes approximately nine months. Before the germ cells merge, the genetic material-which in normal cells occurs as a set of two—is reduced to a single set of chromosomes. This … Read more
Earth Science: Humans – Development Human development begins when two gametes from the parents fuse to form the zygote. A new individual develops from the zygote over the course of about nine months. After puberty, humans are sexually mature and can reproduce. As the body ages, the efficiency and function of the organs gradually diminishes. … Read more
Earth Science: Human beings The human body is an exquisitely complex mechanism. Its tissues and organ systems constantly work together to carry out the functions necessary to support life. The body’s form and function are the result of a long evolutionary process, which is still ongoing today. We perceive our environment through our sense organs. … Read more
Earth Science: Human From a biological point of view human beings are grouped with mammals, more specifically with the great apes. However, humans hold a special place because of their highly developed brain. The human brain made it possible to cultivate complex languages and thus pass along new knowledge from generation to generation. The ability … Read more
Earth Science: Mammals – Humans Modern humans, Homo sapiens, are distinguished from other living things by several physical characteristics and by the many intellectual and cultural achievements of several millennia. No other living creature looks, lives, or moves like a human being. The evolution of humans has been supported by changes in the skeleton in … Read more
