6. When humans first appear on Earth?

How many chromosomes are in a gold fish?

Ascientist separates a population of mice into two groups. what would most likely increase the rate of speciation in this population. a. teach the two groups different tricks b. allow the two groups to breed with each other c. put the two groups in different environment d. have the two groups live in identical ecosystems

Chloroplasts and bacteria are in size. a. similar b. at different ends of the size range c. exactly the same d. none of these