Levels of Organization
Smallest functional and structural unit of all living organisms.
What is a cell?
Strong muscle that pumps blood around your body.
What is the heart?
The system responsible for bringing oxygen into the body and removing carbon dioxide.
What is the respiratory system?
This organ is the control centre of your body.
What is the brain?
The body system that gives support and helps you move.
What is the musculoskeletal system?
A group of similar cells working together to do one job.
What is tissue?
Cleans blood, stores energy, and helps break down food.
What is the liver?
Air enters the body through these structures and gets warmed up.
What are the mouth and nasal cavity?
Network that transmits signals between the brain and body.
What is the nervous system?
This cage of bones protects your lungs.
What is the rib cage?
Made of two or more types of tissue organized to perform a specific function.
What is an organ?
Mash and mix food so your body can digest it.
What is the stomach?
Tube that carries air down into the chest before it branches.
What is the trachea?
Nerves that send information about the outside world to your brain.
What are sensory nerves?
This muscle below the lungs allows you to inhale and exhale.
What is the diaphragm?
A group of organs that work together to perform one or more functions.
What is an organ system?
Helps you breathe by taking in oxygen and removing carbon dioxide.
What are the lungs?
These two tubes carry air into each lung.
What are the bronchi?
This controls breathing, heartbeat, and digestion — automatic actions.
What is the brainstem?
These two systems work together to deliver oxygen to all cells: one brings it in, one moves it around.
What are the respiratory and circulatory systems?
Put these in order from smallest to largest: Organ system, Tissue, Organ, Cell.
Cell → Tissue → Organ → Organ system
These organs act like filters to remove extra water from the blood.
What are the kidneys?
Tiny air sacs where gas exchange happens — there are millions of them.
What are alveoli?
These organs are part of the nervous system because they sense the environment from outside the body.
What are the external (sense) organs — eyes, ears, nose, skin, mouth?
This system uses the nervous system to tell muscles how and when to move.
What is the musculoskeletal system working with the nervous system?