If a few sunspots cool the earth, why don't many sunspots make it even colder?

Kelly ran electricity though a sample of water using electrolysis. the water changed into two gases, x and y. it was not possible to break down the gases x and y into simpler particles.

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.

If assuming tasting ptc as a simple gene trait, what other genotype would you select to put in this missing genotype box that could result in this phenotype