Why do doctors check for swollen lymph nodes?

a. bacteria and viruses mostly attack the lymph nodes.

b. memory cells are stored in the lymph nodes

c. it is impossible to immunize the lymph nodes

d. lymph nodes are the site of white blood cell production

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?

When plants use sunlight to make food, the energy of sunlight is

Ascientist is examinin the cell is disrupted when she damages one specific type of macromolecule g the function of macromolecules in a cell she notices that movenent of large molecules into and out of