Tolerance range refers to the range of conditions of the external environment an organism is able to withstand. The population size of a certain species can be lowered if conditions are outside optimum range. The population is lowered because the organisms cannot survive if there is too much or too little of a factor.
a. What is a star's spectrum?
A star's spectrum refers to the <em>"amount of light"</em> that stars they give off according to varying wavelengths. Since we cannot tell the amount of light a star gives off quantitatively from Earth, we can differentiate them according to how bright they appear.
b. Which spectrum is most common in stars?
Stars are classified according to their spectra <em>(elements in the star)</em>. They are classified into 7 types <em>(O, B, A, F, G, K and O). </em>The most common type is M, however, it gives off a dim light.
c. How can it differ from start to star?
Although stars follow a continuous spectrum, the spectra of a star differs from each other because <u>they do not give off the same amount of energy at the different wavelengths. </u>
d. What does the spectrum tell us about the star?
The spectrum can tell the<em> surface temperature</em> of the star. This means that a blue star (we often see it as a white-colored star from Earth) is hotter than that of a yellow star. A red star is considered the coolest star among all.
The spectrum of stars also allows the astronomers to study composition of the stars according to their <em>wavelengths.</em>
Answer and explanation:
As for <u>oligotrophic lake</u>, the answers would be as follows:
<u>Oxygen level (+).</u> This is because oligotrophic lakes are usually deep waters, and it's on deep waters that oxygen is usually far more contained and dissolved.
<u>Nutrient content (-). </u> Oligotrophic lakes handle a really low level of nutrients. This is the reason why it's inhospitable for any type of fauna and vegetation.
<u>Productivity (-). </u>Following what it's stated above, oligotrophic lakes are essentially unproductive because of its poor nutrient content.