Birds
Birds are organisms which utilize a one-way air flow through their lungs to maximize air flow efficiency and <span>oxygen consumption
</span>The process of respiration is essential in the oxygen/carbon dioxide cycle. Respiration removes OXYGEN <span>from the atmosphere and produces and releases </span>CARBON DIOXIDE to the atmosphere.answer is letter D.
<span>Respiration driven by a mechanical series called inhalation and exhalation. We inhale or breathe in oxygen and exhale or breathe out carbon dioxide. </span>
Cytoplasm is a jello like substance that hold all the cells organelles in place|
Imaging a fruit cup with jello in it,the fruits in the cup represent organelles and the jello in the cup represents cytoplasm.
Well the niche of a squirrel mostly depends on the niche of a temperate rainforest.The trees need water and sunlight to make a nut.Then the squirrel finds the nut and stores it for the winter
I'm not sure if I will answer the question you asked, as I many have interpreted it incorrectly. In natural selection, there must be variance in the gene pool, the total frequency of alleles in a population. Now, one of the organisms may have a gene that somehow helps them survive from the selective force much better compared to the others. If this does happen, over time the gene pool will narrow down to become just the genes of that organism that survived better in the first place because the rest would be taken care of by the selective force. So, the alleles and trait come from the first organisms that had the advantage over the others of its species.