What is activation energy?

20. in humans, freckles are dominant to no freckles. trey has no freckles and his wife anna grace has freckles, but her dad doesn't. they want to know what percentage of their kids would look like trey. show a punnett square to support your answer.

Which of the following is a reason why early living organisms on earth could not have survived on the surface? 1. the lack of an ozone layer 2. the lack of oxygen in the atmosphere 3. the fact that these organisms were single-celled

The lineage of pea plants produced round seeds for four generations. the plants that fertilized these pea plants also produced round seeds. however, in the fifth generation, the plant produced to two plants with wrinkled seeds. can that be possible?