What substances are the reactants in photosynthesis

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.

What is turgor pressure, what causes it, and what does it do for a plant?

Vessels draining the myocardium of the heart, open primarily ,into which chamber?