Answer:
It means that from time to time, organisms change in form and function
Explanation:
As organisms live, they change and develop/mutate into better, stronger, and more functional creatures. This is in addition, because of the cells in the body.
The electrons needed by photosystem ii originate from water.
Answer:
Blastocyst,Blastoderm
Explanation:
The blastula is made up of a hollow spherical layer of cells, referred to as the blastoderm which surrounds a yolk or fluid-filled space called the blastocele or blastocoel. In most mammals, including humans, the structure formed next is the blastocyst, a mass of inner cells that are distinct from the blastula
I would say energy myself, and this is because energy plays a key role in all of these. With trophic levels energy is being transferred amongst the levels. Food chain's is a map of how the energy is passed along the chain. Food web is a web of how energy is transferred, and this is why I would say energy is a keyword.
Answer:
The populations become adapted to different environments and eventually become so different that they cannot interbreed to produce fertile offspring.
Speciation is the evolution of one species into two different kinds, and when they become isolated, that is the final step, since they cannot interbreed any longer.