|Topics||Atomic Mass, Cell Division, Cirrus Clouds, Crust, Gas, Moon, Mouth & Throat, Producers, Somatic Nervous System|
The atomic mass of an element listed in the Periodic Table represents the average mass of a single atom of that element and is measured in atomic mass units (amu). This number is an average as some elements have isotopes with atoms that vary in their number of neturons and, therefore, differ in weight.
Cell division is the process by which cells replicate genetic material in the nucleus. Cell division consists of several phases:
|interphase||chromosomes replicate into chromatids and the cell grows|
|prophase||chromatids pair up|
|metaphase||paired chromatids move to opposite sides of the cell|
|anaphase||cell elongates and nucleus begins to separate|
|telophase||separation of nucleus is complete resulting in two new nuclei|
|cytokinesis||cytoplasm and cell membranes complete their separation resulting in two separate cells|
Cirrus clouds are thin, wispy high-altitude clouds composed of ice crystals that originate from the freezing of supercooled water droplets. Cirrus clouds generally occur in fair weather and point in the direction of air movement at their elevation.
The crust is the Earth's outermost layer and is divided into oceanic and continental types. Oceanic crust is 3 miles (5 km) to 6 miles (10 km) thick and is composed primarily of denser rock. Continental crust is 20 to 30 miles (30 to 50 km) thick and composed primarily of less dense rock. The crust makes up approximately one percent of the Earth's total volume.
The gaseous state occurs at a higher temperature range than the solid and liquid states of the same substance. In this state, molecules flow very freely around each other and will spread out as far as they're able. Gases maintain neither a constant volume nor a constant shape.
Tides are caused by the gravitational interaction of Earth and the Moon.
Digestion begins in the mouth where the teeth and tongue break down food mechanically through chewing and saliva, via the enzyme salivary amylase, starts to break starches down chemically. From the mouth, food travels down the esophagus where contractions push the food into the stomach.
Producers (autotrophs) serve as a food source for other organisms. Typical producers are plants that can make their own food through photosynthesis and certain bacteria that are capable of converting inorganic substances into food through chemosynthesis
Part of the peripheral nervous system, the somatic nervous system is made up of nerve fibers that send sensory information to the central nervous system and control voluntary actions.