<span>Plato first proposed that the planets followed perfect circular orbits around the Earth. Later, Heraclides (330 B.C.) developed the first Solar System model, placing the planets in order from the Earth it was is now called the geocentric solar system model.
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When there is not enough oxygen for cells to use cellular respiration<span />
A dichotomous key helps you identify unknown specimens based on their traits because there are only two options available per trait. Selecting one from the two options (usually contrasting characteristics) from each step leads to smaller and smaller groups until the option is reduced to single and unique trait of an organism.
Considering you need to identify an organism. So, on the top of they key is animal with options: (a) with red blood cells and (b) no red blood cells. The option you will select is no red blood cells and under option b, you’re given two choices again: (a) hard bodies and (b) soft bodies. You’ll select soft bodies, then two options again are given: (a) with shell and (b) without shell. The option you’ll select would be without shell, and so on.
Answer: Nonpolar lipid layers
Explanation:
Answer:So yes,humans and other mammals (like dogs) have same immune system. Differences may occur in the protein structures, but they all come in same family and work similarly like humans.
Explanation: Are animal immune systems different from humans? - Quora
https://www.quora.com/Are-animal-immune-systems-different-from-humans