Levels of Organization
What level of organization is the heart?
Organ
Which two systems work together to move oxygen from the air to cells?
Respiratory and circulatory
In what organelle does cellular respiration occur?
Mitochondria
If solute concentration is higher outside the cell, which way does water move?
Out of the cell
Which macromolecule provides amino acids like leucine?
Protein
What level of organization includes the heart, blood, and blood vessels working together?
Organ system
Which system filters liquid waste from the blood?
Excretory
What is the main purpose of cellular respiration?
To release energy in the form of ATP
What does equilibrium mean?
Particles continue moving but equally in all directions
After eating, why does blood glucose rise?
Glucose is absorbed into the bloodstream from the small intestine.
What are tissues made of?
Cells
Which system breaks food into usable molecules?
Digestive
What two reactants are required for cellular respiration?
Glucose (C₆H₁₂O₆) and oxygen (O₂)
What is the term for water moving across a semipermeable membrane?
Osmosis
What molecule carries energy used by cells?
ATP
Cardiac muscle cells → cardiac tissue → heart → circulatory system.
What concept does this sequence demonstrate?
Increasing levels of organization
Which system absorbs nutrients into the bloodstream?
Digestive
What two waste products are produced?
Carbon dioxide (CO₂) and water (H₂O)
If a protist pumps very little water out in a salt solution, what does that suggest?
The solution is close to its internal concentration (near equilibrium).
Which sequence correctly represents nutrient movement?
Digestion → bloodstream → cells → energy release
How does structure relate to function in the circulatory system?
Specialized cells form tissues that allow the heart to contract rhythmically, which allows the system to transport materials.
Explain how digestive, respiratory, and circulatory systems work together to release energy from food.
Digestive breaks food into molecules, respiratory brings in oxygen, circulatory transports both to cells for cellular respiration.
During cellular respiration, what happens to matter and energy?
Matter is rearranged and energy is released.
Why do cells regulate water movement?
To maintain homeostasis and prevent shrinking or bursting.
Why can humans survive longer without food than isolated cells in a lab?
The body can redistribute stored nutrients between systems; isolated cells cannot.