The in the root is a single layer of cells sandwiched between the cortex and the stele. This layer acts as a selective barrier that regulates the passage of substances from the soil to the vascular tissue

With the description of the different cell walls, membranes, and associated proteins set in the students' minds, you now need to introduce them to the idea that the cell wall can also act as a foundation to build things upon. bacterial appendages require a strong foundation that will offer the support needed to move and function in a dynamic world. for example, flagella are long, whiplike protein structures that are used by many gram-positive and gram-negative bacteria for locomotion. in order to function effectively, a flagellum must be firmly anchored to the cell wall. how will you be able to get across the idea that the peptidoglycan cell wall is strong enough to support such a mechanism? with a protein rod that passes through the cell wall and protein rings used to anchor it in the membranes, these basal bodies are the rudimentary biological motors that use atp power to spin the hook and the flagella attached to it. bacterial flagella have a biological motor that spins within the cell wall and is powered by atp. this allows the flagella to spin in a whiplike motion to propel the bacterium.

Which best describes a rhinovirus? o a. a virus that causes a common cold o b. a protective shell around a virus o c. a tube the comes off a virus o d. a piece of dna transferred by a virus

Explain why the plants cortex would serve as the best food source for animals