Body Systems
Which body system pumps blood throughout your body?
Circulatory system
What does the word multicellular mean?
Made of many cells
What is the basic unit of life?
The cell
What does unicellular mean?
Made of one cell
A metal spoon and a wooden spoon sit in the same room. Why might the metal spoon feel colder when you touch it?
Metal conducts heat away from your hand faster than wood
What organ allows you to take oxygen into your body?
The lungs exchange oxygen and carbon dioxide
What is the correct order of organization in a complex multicellular organism?
Cells → tissues → organs → organ systems
Which cell structure controls what enters and leaves the cell?
Cell membrane
Give an example of a unicellular organism?
An amoeba
You mix two clear liquids, and the mixture produces bubbles without boiling. What might this be evidence of?
Unexpected gas production can be evidence of a chemical reaction
Which body system sends messages between your brain and the rest of your body?
The nervous system carries messages
What is a group of similar cells working together called?
A tissue is a group of similar cells working together
Which organelle releases usable energy from food for the cell?
Mitochondria
How does a unicellular organism carry out the functions needed for life?
One cell carries out all necessary life functions
An object has a mass of 20 grams and a volume of 5 cubic centimeters. What is its density?
Density = mass / volume = 4 g/cm³
What body system breaks down food so your body can absorb nutrients?
The digestive system breaks down food
Give an example of a multicellular organism?
Humans are multicellular
What is the main job of the nucleus in most plant and animal cells?
Contains DNA and helps direct cell activities
Give an example of a microorganism that can live in many different environments?
Bacteria are microorganisms found in many environments
What happens to most materials when they are heated?
Heating generally increases particle motion
Which two body systems work together to help you move?
Muscles pull on bones to create movement
Why do multicellular organisms need specialized cells?
Specialized cells perform different functions
Which cell structure makes proteins?
Ribosomes
How can some unicellular organisms reproduce?
Cell division
A toy car travels 12 meters in 3 seconds. What is its average speed?
Speed = distance / time = 12 / 3 = 4 m/s