Which of these is a physical change that happens during digestion?
Enzymes in saliva break food down
Stomach acid breaks down food
The mouth mashes food
The liver and pancreas break down food
15
Which of these is not part of the circulatory system?
Lungs
Heart
Arteries
Veins
15
What are the tiny air sacs in your lungs called?
Pharynx
Alveoli
Trachea
Bronchioles
15
What type of muscle is the heart made out of?
Smooth muscle
Cardiac muscle
Rough muscle
Long muscle
15
Leaves are composed of vascular tissue that brings water in so that ground tissue can conduct photosynthesis. Based on this information, what level of organization describes leaves?
