The greenhouse effect occurs when rays enter our atmosphere and are reflected from the ground up. They get changed during their voyage through our atmosphere and they change in such a way that they can't leave the atmosphere anymore. Then they stay inside and heat up the planet which causes thing like global warming. That's what the greenhouse effect is.
Variations are beneficial for the survival of the species. Populations of organisms fill well-defined places, or niches, in the ecosystem, using their ability to reproduce.However, if some variations were to be present in a few individuals in these populations, there would be some chance for them to survive.
In meiosis, the homologues separate in anaphase I and the sister chromatids separate in anaphase II.
A seedling is a young plant sporophyte creating out of a plant incipient organism from a seed. Seedling improvement begins with germination of the seed. A common youthful seedling comprises of three fundamental parts: the radicle, the hypocotyl, and the cotyledons.