Asubstance directly involved in cellular communication within the human body is

Average annual precipitation and are the two major features that define the biomes on earth.

Study the image of this rock. which characteristic best supports its formation from sedimentary processes? it has many layers. it is coarse-grained. its grain shape is round. its texture is non-banded.

Why is it important to reduce the number of chromosomes in half when forming gametes for sexual reproduction?