I need to know answers to all three please and fast 18. If you were conducting an experiment, you would change only one thing,
A. to support your hypothesis.
C. to know exactly what caused the results.
B.
because there is only one constant in an
D.
experiment.
to simplify the experiment so results are more
understandable.
_19. A hypothesis is
A.
a proven statement.
C. a definite answer to a given problem.
B. a concluding statement.
D. a testable possible explanation of an observation.
20. A controlled experiment
A. introduces bias.
C. tests several variables at once.
B.
tests only one variable and is free of bias.
D.
changes no variables.

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.

The graph shows the amount of global warming happening in different ecosystems. which populations of organisms will likely decline the most as a result of climate change, and why? a.coral reefs because of the loss of the symbiotic algae living within their bodies b.penguin populations because the fish they eat will move into warmer waters c.mountain-dwelling birds because rising sea levels will relocate their food sources d.large cats in the rainforest because of decreased habitat loss for their prey

Up to what percentage of the world's flora consisted of cycads during the triassic period? 100% 75% 50% 20%