Some chemical signals are received by specific target cells. what is required for reception by a target cell?

What are tissues? a groups of tissues that work together b basic units of structure and function c groups of cells that perform the same function d multiple organs that perform a major function

Many farmers prefer cattle without horns because it is safer for their herds. the allele for no horns (n) is dominant to the allele for the presence of horns (n). a farmer mates a male with horns to a heterozygous female without horns. what is the chance that the offspring will have horns?

Why does the earth spin slowly, not faster? is it possible to prove it scientifically? can you prove it with math?