Gamete - A reproductive cell that carries half of the genetic material of the complete organism.
Gas - A state of matter in which the substance has no definite shape or volume. The substance will take the shape of its container and fill all available space.
Gene - a piece of a chromosome that controls a particular trait, either by itself or with other genes.
Genetic traits - a specific characteristic of an individual that is passed down from its parents.
Genetically modified organism - an animal, plant, or microbe whose DNA has been altered using genetic engineering techniques
Genotype - The genetic combination that is inherited from parents. It is usually noted by a two letter combination.
Geologic time scale - the full representation of the entire geological and biological history of Earth.
Geologist - a scientist who specializes in the study of rocks.
Geothermal - A type of renewable energy source that uses the heat trapped within the earth to provide heat and electricity.
Gibbous Moon - Any moon phase where more than half of the face of the moon is lit up. It comes before or after a Full Moon.
Global Warming - the long-term increase in the Earth's average surface temperature, mainly due to human activities that release greenhouse gases like carbon dioxide
Graduated cylinder - a tall, skinny measuring cup with numbers along the side, used to measure the amount of liquid an object can hold
Gravity - a force that pulls objects toward each other. The more mass an object has, the greater the force and the closer they are, the greater the force.
Gregor Mendel - An Austrian monk whose early work with studying pea plants laid the foundation for the basis of genetics. He is known as the “Father of Genetics”
Greenhouse Effect - a natural process that traps the heat from the Sun to help warm up the Earth. This effect has increased in recent years due to human activities.
Group – a vertical column (up and down) on the periodic table. Elements in the same group share similar chemical properties.
Haploid - cells that contain half the number of chromosomes found in body cells
Heterogeneous Mixture - a combination of two or more substances in which you can easily see the different parts of the mixture.
Heterozygous - An organism that has one dominant allele and one recessive allele.
High Pressure - An area of atmospheric pressure that is higher than its surrounding environment. High-pressure systems are typically associated with fair weather and clear skies.
High Tide - The highest point the ocean level will rise to at a particular place during the day.
Homogeneous Mixture - a combination of two or more substances in which you cannot tell the different parts of the mixture.
Homologous structures - similar structures found in different species due to a common ancestor, like the hands of a human and the flippers of a dolphin
Homozygous dominant - An organism that has two dominant alleles for a particular trait
Homozygous recessive - An organism that has two recessive alleles for a particular trait
Humidity - The amount of water vapor present in the air, usually expressed as a percentage of the maximum amount the air could hold at a given temperature and pressure.
Hurricane - A large, powerful tropical cyclone characterized by strong winds (exceeding 74 miles per hour), heavy rainfall, and low atmospheric pressure. Hurricanes typically form over warm ocean waters and can cause widespread destruction and flooding when they make landfall.
Hydrocarbons - A substance that is made of only carbon and hydrogen. They are often used as fuel sources like coal, petroleum or natural gas.
Hydroelectric - A type of energy source that uses flowing water from things like rivers to produce electricity.