A water molecule, because of its shape, is a polar molecule. That is, it has one side that is positively charged and one side that is negatively charged. The molecule is made up of two hydrogen atoms and one oxygen atom. The bonds between the atoms are called covalent bonds, because the atoms share electrons.
Overproduction of young passing on acquired traits survival of the strongest natural selection
An absorptive heterotroph is an organism which secretes enzymes externally into its environment to digest organic materials which are then absorbed.
An ecosystem is a community of living organisms in conjunction with the nonliving components of their environment, interacting as a system. ... By feeding on plants and on one-another, animals play an important role in the movement of matter and energy through the system.