1) What is the significance of the Casparian strip in the root physiology?

It actively takes up important ions

It protects the roots from desiccation

It forces minerals and other substances to pass through a cell membrane before entering the xylem

It forces minerals and other substances to pass through a cell membrane before entering the phloem

2) Which of the following is considered part of a plant’s vascular tissue?

Cork cambium

Cortex

Tracheids

Guard cells

3) Why would natural selection favor plants releasing carbohydrates into the soil surrounding their roots?

Plants produce more sugars than they can use, so they need to eliminate excess sugars as waste

It enhances the populations of soil bacteria, which in turn make more nutrients available to the plant

Releasing carbohydrates into the soil can attract subterranean army ants which will then defend the plant from all herbivores

By releasing carbohydrates into the soil the plant can eliminate the need for mycorrhizal fungi