Characteristics of Living Things and Cell Theory

The outer boundary of a cell that controls what enters and exits. It provides structural support and acts as a barrier.

A specialized structure within a cell that performs a specific function. Examples include the nucleus, mitochondria, and Golgi apparatus.

The watery, gel-like substance inside a cell where organelles are suspended. It supports and provides a medium for chemical reactions.

A membrane-bound organelle that contains the cell's DNA and controls cell division.

A membrane-bound organelle that breaks down glucose to release energy in the form of ATP. This is known as cellular respiration.

Small changes in the genetic material of a cell that occur during cell division.

The theory that states all living organisms are composed of cells and that cells arise from pre-existing cells. It's a fundamental principle in biology.

The outdated theory that living organisms could arise spontaneously from non-living matter.

A group of interacting parts that work together to perform a specific function.

The cell is considered a living system because it carries out all the functions necessary for life, such as metabolism, reproduction, and response to stimuli.

An Italian scientist who disproved spontaneous generation by showing that maggots only appear on meat when flies are present. His experiments helped establish the need for controlled observations and experimentation.

French scientist who conducted experiments using swan-neck flasks to disprove spontaneous generation once and for all. His work demonstrated that microorganisms are responsible for causing decay, not spontaneous generation.

The basic unit of life. All living organisms are made up of one or more cells. Cells are responsible for carrying out all functions necessary for life.

A group of cells that work together to perform a specific function. Examples include the nervous system, the digestive system, and the circulatory system.

The components that make up a system. For example, the organelles within a cell are components of the cell.

The cell theory is the fundamental concept in biology that states all living organisms are composed of one or more cells. It also explains that cells are the basic building blocks of life and that new cells arise from pre-existing cells.

A unicellular organism consists of a single cell that carries out all life processes. Examples include bacteria and yeast.

A multicellular organism is made up of many cells that work together to perform specialized functions. Examples include humans, plants, and animals.

Abiogenesis, also known as spontaneous generation, is the outdated theory that believed living organisms could arise from non-living matter. This idea has been debunked by modern scientific understanding.

The process of metabolism refers to all chemical reactions that occur within a living organism to maintain life. This includes breaking down food for energy (catabolism) and building complex molecules (anabolism).

Living organisms are composed of complex chemical substances, such as proteins, carbohydrates, fats, and nucleic acids. These molecules are organized into structures like organs and tissues.

Living organisms require energy to perform essential life processes, such as growth, movement, and reproduction. This energy is obtained from food or sunlight.

Homeostasis is the ability of living organisms to maintain a stable internal environment despite changes in the external environment. For example, regulating body temperature or blood sugar.

A type of endoplasmic reticulum (ER) that does not have ribosomes attached to its surface. It's mainly involved in lipid metabolism and is found near the cell membrane.

A type of endoplasmic reticulum (ER) with ribosomes attached to its surface. Its main function is protein synthesis, and it's located near the nucleus.

Simple, single-celled organisms like bacteria. They lack a nucleus and other membrane-bound organelles. Their DNA is free-floating within the cell.

Complex cells found in fungi, plants, and animals. They have a nucleus containing their DNA and other membrane-bound organelles.

Living organisms that are made up of only one cell. Examples include bacteria and some algae.

Living organisms made up of many cells that work together to perform specific functions. Examples include plants, animals, and fungi.

The process by which cells divide to create new cells. It's essential for growth, repair, and reproduction.

A type of cell division that results in four daughter cells, each with half the number of chromosomes as the original parent cell. It's essential for sexual reproduction.