Plz no bit. yl stuff, just answers Sickle cell anemia is a disease that affects the circulatory system. It can be passed from parent to child. Which of the following indicates the significance of this disease?
A. It shows that a disease can cause genetic changes.
B. It is a reflection of how genetic factors affect health.
C. It shows how public health is affected by environmental factors.
D. It indicates how a toxin can play a role in the development of disease.

Which best explains why viruses do not have special structures or enzymes that allow them to make their own food? viruses can use energy in living cells that they infect. viruses can replicate inside a host that they infect. viruses can cause contagious illnesses in host cells. viruses integrate their rna or dna into infected cells.

The model illustrates a process by which a substance is taken up by a cell

Sally and sue were investigating the topic of friction in science. they used a small car and a ramp as seen in the picture to test what they were learning. they knew that they slipped easily on waxed floors but not on carpet, so they decided to change the material on the surface of the ramp to see what happened. they planned to use glass, carpet, aluminum foil, and sandpaper and run the car down the ramp over each surface. what would be the best research question to guide the girls' experiment? a) does the amount of surface area affect the friction on the moving car? b) will the car travel fastest on the glass surface? c) how does the angle of the ramp affect the speed of the car? d)do rougher surfaces tend to create more friction than smooth surfaces?