The earth' is a source of fossil fuel
a. trees
b. land
c. water

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.

Keeping in mind the life cycle of bacteriophages, consider the following problem: during the reproductive cycle of a temperate bacteriophage, the viral dna inserts into the bacterial chromosome where the resultant prophage behaves much like a trojan horse. it can remain quiescent, or it can become lytic and initiate a burst of progeny viruses. several operons maintain the prophage state by interacting with a repressor that keeps the lytic cycle in check. insults (ultraviolet light, for example) to the bacterial cell lead to a partial breakdown of the repressor, which in turn causes the production of enzymes involved in the lytic cycle. as stated in this simple form, would you consider this system of regulation to be operating under positive or negative control?

In 2015, about ten percent of total u.s. energy consumption was from renewable energy sources. renewable energy plays an important role in reducing greenhouse gas emissions. when renewable energy sources are used, the demand for fossil fuels is reduced. sanjay and his family want to cut back on their use of non-renewable resources at home. they are thinking of an alternate way to heat their home without adding more greenhouse gases or pollutants to the environment. which renewable resource would not fit into their plan? a) solar power b) burning wood c) constructing a wind turbine eliminate d) generating hydroelectric power