During which century did charles darwin come up with his theory?

In which terrestrial biome can you find trees that produce cones instead of flowers and needles instead of leaves? have trees that produce cones instead of flowers and needles instead of leaves. the latitudes in this biome have evenly distributed precipitation throughout the year. is it high or low

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?

All ova contain sex chromosomes corresponding to: x y xx xy