Answer:
third and fourth trophic levels
Explanation:
Lipids don't dissolve in water because of the different polarities. Water is polar and lipids are not polar which is why they don't dissolve. What this means is that they don't bond and don't share electrons and therefore don't mix.
Some isotopes, however, decay slowly, and several of these are used as geologic clocks. Dating rocks by these radioactive timekeepers is simple in theory, but the laboratory procedures are complex. <span>All methods rely on the fact that certain elements (particularly uranium and potassium) contain a number of different isotopes whose half-life is exactly known and therefore the relative concentrations of these isotopes within a rock or mineral can measure the age.</span>
Answer:
B) cells or tissue that produce light
Explanation:
It wouldn't be A because photophores do not affect the color of other organisms.
It wouldn't be C because the cells produce light, they don't necessarily change color.
Lastly, it wouldn't be D because it isn't a whole organism producing the light, it's an organ. Organs are multiple tissues working together, and tissues are groups of cells.
The best estimate for Earth's age is based on radiometric dating of fragments from the Canyon Diablo iron meteorite. From the fragments, scientist calculated the relative abundances of elements that formed as radioactive uranium decayed over billions of years.