| A | B |
|---|
| half - left | look up |
| Halogen | A nonmetal in Group 7A of the periodic table |
| heat energy | heat: a form of energy that is transferred by a difference in temperature |
| heat source | A medium or container from which heat flows. |
| heliocentric | having the sun as the center |
| hemoglobin | the oxygen-carrying pigment of red blood cells that gives them their red color and serves to convey oxygen to the tissues: occurs in reduced form (deoxyhemoglobin) in venous blood and in combination with oxygen (oxyhemoglobin) in arterial blood |
| herbivores | An animal that feeds mainly or only on plants. In a food chain, herbivores are primary consumers. |
| Heredity | Transmission of genetic characters |
| Hertzspurng - Russell diagram | scatter graph of stars showing the relationship between the stars' absolute magnitudes or luminosity versus their spectral types or classifications and effective temperatures. |
| heterotrophs | an organism requiring organic compounds for its principal source of food. |
| Heterozygous | having dissimilar pairs or genes |
| homeostasis | the tendency of a system, esp. the physiological system of higher animals, to maintain internal stability, owing to the coordinated response of its parts to any situation or stimulus tending to disturb its normal condition or function |
| Homologous | having identical pairs of genes |
| horizontal axis | axis of graph that is at right angle to vertical - x axis |
| humus | partially decomposed organic matter; the organic component of soil |
| hybrid | look up |
| hydrogen bond | a type of chemical bond in which a hydrogen atom that has a covalent link with one of the electronegative atoms (F, N, O) forms an electrostatic link with another electronegative atom in the same or another molecule |
| hydrosphere | look up |
| hypothesis | A tentative explanation for an observation, phenomenon, or scientific problem that can be tested by further investigation. |
| independent variable | variable being manipulated or changed |
| immunity | look up |
| inerita | look up |
| inference | look up |
| infrared | look up |
| Inheritance | the genetic characters transmitted from parent to offspring, taken collectively. |
| insulator | a material of such low conductivity that the flow of current through it is negligible |
| intensity | magnitude, as of energy or a force per unit of area, volume, time |
| Investigation | a searching inquiry for ascertaining facts; detailed or careful examination |
| ion | one of the electrically charged particles formed in a gas by electric discharge or the like |
| ionic bond | the electrostatic bond between two ions formed through the transfer of one or more electrons. |
| Ionic Compound | A compound composed of positive and negative ions |
| isotope | any of two or more forms of a chemical element, having the same number of protons in the nucleus, or the same atomic number, but having different numbers of neutrons in the nucleus, or different atomic weights |
| Issue | a point in question or a matter that is in dispute |
