Muscle fibers are made of myofibrils which are small cylinder-shaped structures. Myofibrils are made up of tiny filaments. Some of these filaments are thin and others are thick.
Osteoblasts make new bone cells called osteocytes. In some types of bones osteocytes are arranged in circular patterns around a common cavity called the Haversian canal.
Bones are covered by a tough membrane called periosteum. Its primary goal is to make new bone for growth and repairs. Small blood vessels branch through the periosteum to move nutrient-rich blood to reach deeper into the bone.
The outer layer of skin, the epidermis, consists of tightly packed epithelial cells that form a layer only about as thick as a piece of paper. The dermis lies below the epidermis and consists of thick layer of connective tissue.
In the process of condensation, water vapor particles in the air become cooled when they touch the side of a can and experience a phase change from a gas to a liquid.
Particles in liquids are not packed as tightly together as they are in solids.
Particles in solids are packed tightly together, making solids relatively hard and allows them to keep their definite shape.
Gas has no definite shape or volume because the particles are packed loosely and can freely move about. The volume of a given amount of gas can adjust to fill a small or large container.
Located beneath the lithosphere, the asthenosphere is approximately 130 to 160 kilometers thick. It is warmer than the lithospehre and has a thick, gooey consistency.
There are seven major continents: North America, South America, Asia, Europe, Africa, Australia, and Antarctica. Antarctica and Australia are isolated, meaning they aren't attached to other continents.
Hot molten material in the asthenosphere rises and sinks in circular flows called convection currents.
Based on mineral composition, there are 3 main layers of the Earth: crust, core, and mantle.
There are 3 main layers of Earth: crust (outer layer), mantle (middle layer), and core (layer at Earth's center).
The mantle is divided into two main parts. The upper mantle is approximately 870 degrees Celsius where as the lower mantle is much hotter at 2,200 degrees Celsius. Rock becomes molten or liquid at these temperatures.
This image depicts the North American plate, one of seven major continental plates that make up the lithosphere.
Earth has three main layers: crust, mantle and the core. This animation depicts the changing qualities of the interior of Earth's surface. The chemical composition of materials changes, and the density, pressure, and temperature increases with depth.
Genetic engineering involves the process of changing the genetic makeup of a living thing.
Genetic material, which makes up genes, consists of DNA.
This animation demonstrates that the surfaces of concave mirrors and lenses curve inward.
This animation demonstrates that the surface of a convex mirror curves outward.