Mitosis

Mitosis

Mitosis Definition Two new cells are formed during mitosis, the step in the cell cycle when the newly duplicated DNA is separated. The process of asexual reproduction is important for single-celled eukaryotes. Multicellular eukaryotes undergo mitosis in order to become an entire organism. The other stages in the cell cycle include growth and the replication … Read more

Active Transport

Active Transport

Definition Active transport is the process of transferring substances into, out of, and between cells, using energy. In some cases, the movement of substances can be accomplished by passive transport, which uses no energy. However, the cell often needs to transport materials against their concentration gradient. In these cases, active transport is required. Process of … Read more

Sympathetic Nervous System

Sympathetic Nervous System

Sympathetic Nervous System Definition The sympathetic nervous system is part of the autonomic nervous system, an extensive network of neurons that regulate involuntary processes. Specifically, the sympathetic nervous system controls aspects of the body related to the flight-or-fight response, such as mobilizing fat reserves, increasing the heart rate, and releasing adrenaline. Sympathetic Nervous System Overview … Read more

Ecological Pyramid

Ecological Pyramid

Ecological Pyramid Definition An ecological pyramid is a graphical representation of the relationship between different organisms in an ecosystem. Each of the bars that make up the pyramid represents a different trophic level, and their order, which is based on who eats whom, represents the flow of energy.  Energy moves up the pyramid, starting with … Read more