Answer:
<em>The correct option is A) an increase in oxygen levels, which led to the extinction of many anaerobic organisms.</em>
Explanation:
Photosynthesis can be described as a process in which food (glucose) is produced by photosynthetic organisms by using carbon dioxide, water along with light energy from the sun. Oxygen is released as a by-product of this reaction. The process of photosynthesis initially allowed for oxygen gas to get accumulated in the air. This caused the rise of aerobic organisms who required oxygen for respiration. Before the photosynthesis organisms evolved, there was not enough oxygen gas on earth to support the life of aerobic organisms.
Scientific Disciplines:
Biochemistry and Molecular Biology.
Cancer Biology.
Cell Biology.
Chemistry:
Developmental Biology and Genetics.
Immunology.
Microbiology.
Neuroscience.
Answer:
Molecular mass or vapor density
Explanation:
The empirical formula is the simplest formula of a compound. The molecular formula expresses the exact formula of the compound. To derive the molecular formula, we need information about its molecular mass or if given the vapor density.
(Empirical Formula)n = Molecular formula ------(i)
n = number of repeating units of the empirical formula present in one mole of the molecule
also, (molar mass of empirical formula)n = molar mass of compound
From here, we can find n and insert in (i) above.
Skin is the first defense structure.
