Levels of Organization
This is the smallest unit of life.
What is a cell?
These two systems work together to move your body.
What are the muscular and skeletal systems?
This is where digestion begins in the body.
What is the mouth?
This organ pumps blood throughout the body.
What is the heart?
This system controls quick responses like movement and reflexes.
What is the nervous system?
Groups of similar cells working together form this.
What is a tissue?
These systems work together to deliver oxygen to cells.
What are the respiratory and circulatory systems?
This movement pushes food through the esophagus.
What is peristalsis?
These tiny air sacs are where gas exchange happens.
What are alveoli?
This part of the nervous system includes the brain and spinal cord.
What is the central nervous system (CNS)?
This level is made of different tissues working together.
What is an organ?
This system carries nutrients absorbed from the digestive system.
What is the circulatory system?
Most digestion and nutrient absorption happens here.
What is the small intestine?
These blood vessels carry oxygen-rich blood away from the heart.
What are arteries?
These neurons carry messages from the body to the brain.
What are sensory neurons?
This level includes groups of organs working together for a major function.
What is an organ system?
The brain sends signals to muscles through these types of neurons.
What are motor neurons?
This organ produces bile to help digest fats.
What is the liver?
This gas is removed from the body during exhalation.
What is carbon dioxide?
This type of response is automatic and very fast.
What is a reflex?
This is the correct order from simplest to most complex.
What is cells → tissues → organs → organ systems?
This process keeps body conditions stable even when systems interact.
What is homeostasis?
This process uses oxygen and glucose to produce energy in cells.
What is cellular respiration?
This is the process by which oxygen moves into the blood in the lungs.
What is diffusion?
This part of a neuron sends messages away from the cell body.
What is the axon?