Answer:
An index fossil is a fossil used to determine the age of the sediments in which it is found. When quickly approximating the age of new finds, an archaeologist looks at the rocks in which it is buried, as those sediments would have been on the surface at the time of the death of the pre-historic creature.
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Structurally, plant and animal cells are very similar because they are both eukaryotic cells. They both contain membrane-bound organelles such as the nucleus, mitochondria, endoplasmic reticulum, golgi apparatus, lysosomes, and peroxisomes. Both also contain similar membranes, cytosol, and cytoskeletal elements.
Answer:
A phospholipid
a. has both polar and nonpolar regions.
Explanation:
Phospholipids, as amphipathic molecules, consist of a glycerol molecule, two fatty acids, and a phosphate group that is modified by an alcohol. The phosphate group is the negatively-charged hydrophilic (water-loving) polar head, which face outward and are attracted to the intracellular and extracellular fluid. The fatty acids are the uncharged, hydrophobic (water-fearing) nonpolar tails, which face the inside, away from the water and meet in the inner region of the membrane.
They do this real fancy thing called breathing. There's a couple other organisms that do this too, but none compare to the frog