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:
When the rule of 70 applies to population, dividing 70 by the percentage of population growth should equal the time (in years) that the population needs to be double (option A)
Explanation:
The rule of 70 is useful to calculate the time in which a variable of any type can be duplicated. The calculation is done by dividing the number 70 by the percentage of growth of the variable.
<u>If the rule of 70 is applied to the population, it is possible to calculate, based on its growth rate, the time that population would need to double</u>.
If, for example, the growth rate of a population is 3 percent:
70 / 3 = 23,33
This indicates that a population, with a growth rate of 3% would need about 23,33 years to double.
Emotion is one of the responses of an organism (whole) which
involves physiological arousal. Other than indicating emotion, physiological
arousal or heightened physiological activity is modernly used in polygraphs.
Polygraphs or lie detector notes changes in blood pressure, pulse, respiration
while the subject is asked and answers questions. It is based on the assumption
that dishonest answers are indicated with physiological arousal.
The
zebrafish lineage is the studied gene who evolved most rapidly as shown in its
branch where it manifest to have the longest lineages.<span> The changing branch lengths indicates
that the gene has evolved at different rates in each lineages and the branch length
is proportional to amount of the genetic variation in each linear.</span>
Answer:
The law of conservation of matter and energy states that matter is neither created nor destroyed but conserved. They can only rearrange the matter and energy. For example, an oxygen atom will cycle through a living system.
