High School Biology Terms I

One of two or more versions of a gene that determine a specific trait, such as eye color

A person inherits one allele for blood type from each parent, and together they determine the person's blood type.

The process by which cells break down sugar to release energy that the body can use

Your muscle cells use cellular respiration to get energy when you exercise.

A thread-like structure found in the nucleus of a cell that carries the genes determining a living thing's characteristics

Humans have 46 chromosomes in most of their cells, arranged in 23 pairs.

An organism such as a fungus or bacterium that breaks down dead plants and animals and returns nutrients to the soil

Mushrooms are decomposers that help break down fallen logs and return nutrients to the forest floor.

The process by which particles spread out from an area of high concentration to an area of low concentration

You can smell a candle across the room because of diffusion, which carries scent particles through the air.

All the living organisms in an area together with the non-living parts of their environment, such as water, soil, and air

A coral reef is a complex ecosystem where thousands of species of fish and plants depend on each other.

A protein in the body that speeds up chemical reactions without being used up itself

The enzyme in your saliva begins to break down food the moment you start chewing.

The complete set of genes an organism has, including genes that may not be visible in its appearance

Two plants can have the same flower color but a different genotype if one carries a hidden gene.

The ability of the body to keep its internal conditions, such as temperature and water levels, stable and balanced

When you feel hot and start to sweat, your body is using homeostasis to keep its temperature normal.

The process by which a cell divides to produce four sex cells, each with half the normal number of chromosomes

Meiosis produces egg and sperm cells that each contain only half of a person's chromosomes.

A structure inside a cell that produces energy for the cell to use, often called the powerhouse of the cell

Muscle cells contain many mitochondria because they need a large amount of energy to move the body.

The process by which a cell divides to produce two identical new cells, used for growth and repair in the body

During mitosis, one skin cell divides into two cells with the same genetic information.

The process by which organisms with traits better suited to their environment survive longer and produce more offspring

Natural selection helped the peppered moth population change color over time to blend in with its environment.

The movement of water through a thin barrier from an area where there is more water to an area where there is less water

Osmosis allows plant roots to absorb water from the soil into their cells.

The physical characteristics of an organism that can be seen or measured, resulting from its genes and environment

A dog's coat color and size are examples of its phenotype.

The process by which plants use sunlight, water, and carbon dioxide to make their own food and release oxygen

Without photosynthesis, plants could not produce the food and oxygen that living things need to survive.

A living thing, usually a plant, that makes its own food from sunlight and provides energy for other organisms in an ecosystem

Grass is a producer because it uses sunlight to make food, which animals like deer then eat.

A tiny structure found in cells that reads genetic instructions and builds proteins

Ribosomes in our cells constantly build the proteins our body needs to grow and function.

The first step in making a protein, in which the information in DNA is copied into a molecule called mRNA

During transcription, the cell copies the instructions from DNA so they can be carried out of the nucleus.

The process in which a cell reads the instructions in mRNA and uses them to build a specific protein

During translation, ribosomes read the mRNA message and assemble the correct amino acids to form a protein.