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What is the basic definition of Biology?

The study of living organisms and their environments


What are the basic characteristics shared by all living organisms?

1. They are organized
2. They acquire materials and energy
3. The are homeostatic
4. They respond to stimuli
5. They reproduce and grow
6. They have an evolutionary history


What is a cell?

The smallest structural and functional unit of an organism/all living thigns


How are cells formed?

Atoms join together to form the molecules that make up a cell


What does it mean to be single-celled?

An organism is made up of only one cell


What does it mean to be multicellular?

An organism is composed of many different types of cells


What is an atom?

Smallest unit of an element composed of electrons, protons, and neutrons


What is a molecule?

The union of two or more atoms of the same or different elements


What is tissue?

A group of cells with a common structure and function


What is an organ?

Composed of tissues functioning together for a specific task


What is an organ system?

Composed of several organs working together


What is an organism?

An individual; complex individuals contain organ systems


What is a population?

Organisms of the same species in a particular area


What is a community?

Interacting populations in a particular area


What is an ecosystem?

A community plus the physical environment


What is a biosphere?

Regions of the Earth's crust, waters, and atmosphere inhabited by living things


What are the levels of biological organization on Earth?

• Atom
• Molecule
• Cell
• Tissue
• Organ
• Organ System
• Organism
• Population
• Community
• Ecosystem
• Biosphere


How do humans and other animals acquire materials and energy?

By eating food


How does food provide energy?

Food provides nutrient molecules which are used as building blocks or for energy.
• Food energy maintains the organization of the cell and of the organism
• Nutrient molecules are broken down completely to provide the necessary energy to convert other nutrient molecules into the parts and products of cells


What is the ultimate source of energy for the majority of life on earth?

The Sun


How does the Sun provide energy?

Plants, algae, and some bacteria harvest the energy of the sun and convert it to chemical energy by a process called photosynthesis. Photosynthesis produces organic chemicals, such as sugars, that serve as the basis for the food chain.


On average, how many cells make up the human body?

More than 100 trillion


What is homeostasis?

The ability of a cell or an organism to maintain an internal environment that operates under specific condition. An example is the human body temperature.


How does an organism respond to stimuli?

Organisms respond to external stimuli by moving toward or away from it. Their bodies respond to internal stimuli by adjusting to compensate for the stimuli, such as overheating.


What does it mean to reproduce?

Reproduction occurs when organisms pass on their genetic information to the next generation


What is growth?

Growth is recognized by an increase in size and often the number of cells as part of the development of an organism


What is development?

In multicellular organisms, development indicates all the changes that occur from the time the egg is fertilized until death, including the repair of injuries.


What is DNA and what purpose does it serve?

Deoxyribonucleic acid; It contains the hereditary information that directs not only the structure of each cell but also its function. DNA is contained within genes.


What are genes?

Genes are short sequences of hereditary material that specify the instructions for a specific trait. Genes contain the information that makes up DNA.


How do genes contribute to human reproduction?

Genes from the father and mother are carried to the offspring by the sperm and egg. The genes direct the growth and development so that the organism eventually resembles the parents.