The organisms<span> that eat the producers are the primary consumers. They tend to be small in size and </span>there<span> are many of them. ... Because of this inefficiency, </span>there<span> is only enough </span>food<span> for a </span>few top<span> level consumers, but </span>there<span> is lots of </span>food<span> for herbivores lower down on the </span>food chain<span>.</span>
Diffusion is the movement of particles from a high concentration area to a low concentration area.
Things that can go through a membrane are ions (charged), small polar molecules. Big molecules can't go through the membrane due to its large size and disrupting the membrane.
Passive transport is the movement of substances acrpss the cell membrane w/o the use of energy. Active transport needs energy to move substances across a cell membrane.
<span>phagocytosis, otherwise known as "cell eating". The cell takes it in by squeezing it through the cell membrane and creating a vesicle.</span>
Darwin went to the continents of Africa and South America, wherein both of them have a tropical grassland/Savanna biome. The grasslands in these continents gave him a chance to notice that species do vary globally. He observed the similarities between the different large, flightless birds species–rheas, ostriches, and emu.
If there is an environmental or selective pressure it will contribute to the evolution of an organism by giving an adnantage to the organisms of a population who have a trait which allows them to survive that change. The advantageous genes will be passed on and the number of organisms with the desirable feature will increase over time, however the number of organisms that lack the characteristic will decrease over time. This is evolution by natural selection.
