Answer:
D. 3:1
Explanation:
Gregor Mendel, in one of his numerous studies, performed a cross between purebred dominant (TT) pea plants and purebred recessive (tt) pea plants. All the offsprings of this cross appeared heterozygous tall (Tt) in the F1 generation.
However, when he self-crossed the F1 generation i.e. Tt × Tt, Mendel obtained a phenotypic ratio of 3 tall plants (dominant traits) : 1 short plant (recessive). This showed that the masked gene (recessive) was still present.
Usually plants rely on animals or the wind to pollinate them. When animals such as bees, butterflies, moths, flies, and hummingbirds pollinate plants, it's accidental. They are not trying to pollinate the plant. When they move to another flower to feed, some of the pollen can rub off onto this new plant's stigma.
Threatened means they are lowering in numbers and nearing to be endangered.
Endangered means they are dangerously close to being extinct
Extinct means there is none of them left in the wild.
I hope this is what you meant.
Explanation:
If water did not expand when freezing, then it would be denser than liquid water when it froze; therefore it would sink and fill lakes or the ocean from bottom to top. Once the oceans filled with ice, life there would not be possible.
