Which of these best describes a hormone? O A. A chemical message with a specific target
O B. An enzyme delivered to a specific gland
O C. Any message carried by the bloodstream
D. A steroid carrying a message to a receptor cell

Which of the following are causes of coastal erosion? check all that apply. beach grasses and other plants trap windblown sand. wave action carves away the coastline. groundwater under pressure is forced to earth’s surface. artificial structures stop the natural flow of sand along the coast. underground caves collapse as bedrock is dissolved.

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.

Pl as time goes by and water goes through the water cycle again and again, the amount of water on earth: increases decreases ostays the same goes up and down