What is the chemical reaction done by plants so that they and us can have energy

Each pair of clay balls represents two planetesimals. if each planetesimal is composed of the same material and is separated he the same distance, which pair experiences the frayed gravitational attraction?

What would be the result if crossing over did not happen during meiosis in humans? a. there would be less genetic variation in humans. b. parents would be more likely to look like their children. c. the human population could not reproduce. d. children would have more chromosomes.

Rachel ate a piece of fruit and happened to drop the seeds in her backyard. after a few weeks, she saw a small plant with flowers growing in the backyard. which group does this plant belong to? a. angiosperms b. gymnosperms c. pteridophytes d. bryophytes e. chytrids