Life Processes: common misconceptions

If your child says… “Sunlight alone gives plants everything needed to make food.”

Ask together

Which materials must enter this leaf besides sunlight?

What’s true

Light cannot replace chlorophyll, water or carbon dioxide.

If your child says… “My stomach finishes all digestion.”

Ask together

Why would the small intestine need digestive juices if the stomach had finished everything?

What’s true

Digestive juices in the small intestine complete the breakdown.

If your child says… “Only my lungs release energy from food.”

Ask together

Where does glucose breakdown happen in this diagram?

What’s true

Breathing supplies oxygen, while muscle cells release energy where they need it.

If your child says… “Air sacs pump oxygen into blood.”

Ask together

Where is oxygen concentration lower: in the air sacs or arriving blood?

What’s true

Oxygen diffuses into arriving blood because its oxygen concentration is lower.

If your child says… “Blood visits a second heart after the lungs.”

Ask together

Does your finger visit another heart, or the other half of this heart?

What’s true

Both routes use the same heart.

If your child says… “Roots alone push water up tall plants.”

Ask together

If roots alone drove the flow, why would leaf water loss matter?

What’s true

Leaf evaporation mainly drives daytime water flow in tall plants, though root pressure can contribute.

If your child says… “Everything filtered becomes urine.”

Ask together

Where do the arrows leaving the tubule lead?

What’s true

Healthy kidney tubules return all filtered glucose and most filtered water to blood.

If your child says… “Plants never make waste.”

Ask together

What happens to waste stored in a leaf when that leaf falls?

What’s true

Plant life processes produce unwanted substances that plants store or release.