Answer:
Chlorophyll is a green pigment found in chloroplast in plants. It absorbs sunlight during the process of photosynthesis. It is a chelate molecule. In a chelate molecule a central metal ion forms bonds with a large organic molecule made of carbon, hydrogen and other elements like nitrogen or oxygen.
In chlorophyll, magnesium is the central metal ion and it is bonded to a large organic molecule called as porphyrin. Porphyrin constitutes four nitrogen atoms to which the central magnesium is bonded in square planar arrangement. Since chlorophyll is responsible for the green color of the leaves, more the green color more the chlorophyll content and more is the nitrogen content. Hence, chlorophyll meter measures this green light and finds out if the plant needs more or less nitrogen.
Organism, population, community, ecosystem, biosphere
creatine phosphate is the chemical that helps to regenerate ATP
One of the reasons why the fish population remains approximately the same from one generation to the next is because not all the eggs laid will survive to adulthood. There are several factors which bring about elimination of the the newly hatched eggs. Examples of these are predators and diseases which eliminate the young offsprings at different stages before they develop into adulthood.
Secondly, production of many eggs by the different fish species leads to competition for survival. Resources such as water, food, oxygen and shelter have to be fought for and its only the fittests that will be able to survive till the reproduction stage.