Dna within the cell is wrapped around nucleosomes to form chromatin. when chromatin is in the form of a 30 nm fibril, how many copies of h1 and h2a histone proteins would be found in a stretch of chromatin containing 20 nucleosomes?

a. 40 h1, 20 h2a
b. 20 h1, 40 h2a
c. 40 h1, 40 h2a
d. 10 h1, 30 h2a
e. 20 h1, 20 h2a

Match the examples to the correct level of organization. 1. system level roses, snakes, puppies 2. organism level roots, stamens, leaves 3. tissue level bone, cartilage, blood 4. organ level heart, veins, arteries

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?

Restless tectonic plates move (shift) between one and fifteen centimeters per year month day minute