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>
Explanation:
Butter, beef suet, and tallow are about 50% saturated, but all other animal fats are more unsaturated than they are saturated.
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Answer:
D
Explanation:
Hormones are bigger than the cell pores hence cannot pass through the cell membrane to influence biochemical processes. Therefore, hormones (such as glucagon and insulin) bind onto receptors on the cell membrane, then transmembrane proteins, such as the G-protein, change conformation activating the secondary messengers inside of the cell. Cyclic- AMP is a major secondary messenger significant in activating protein kinases.
The problems that will receive priority are the physiological needs such as air, food and water.
Maslow's hierarchy of needs is a theory in psychology which organizes people's needs according to their priorities. It is represented as a pyramid with five steps which include: physiological(at the base), safety, belongingness, esteem and self actualization.
The physiological needs at the base of the pyramid are the first priorities.
