Correct answer - 120 for Thymine.
Why? - 320 Nitrogen bases.
Cytosine = 40, Cytosine = Guanine.
Therefore Guanine = 40.
320 - 80(Cytosine and Guanine)
240.
Adenine and Thymine = ?
Adenine = x and Thymine = x.
2x = 240.
X = 240/2
X = 120.
Adenine 120, Thymine = 120, Cytosine = 40 and Guanine = 40.
The Precambrian era envelopes the major bulk of the history of the Earth, beginning from the creation of the planet approx 4.5 billion years ago and terminating with the origination of composite, multicelled forms of life approximately 4 billion years after.
The Precambrian refers to the earliest of the geologic ages that are signified by the distinct layers of sedimentary rock. The Earth was about more than six hundred million years old when life started. The planet had cooled down from its native molten state, creating a solid crust and oceans formed by water vapor in the atmosphere.
At about three billion years ago, the atmosphere of the Earth was virtually devoid of oxygen. At approximately 2.4 billion years ago, oxygen was discharged from the seas as a waste product of photosynthesis by cyanobacteria. The levels of the gas slowly raised, attaining about 1 percent around two billion years ago.
Approximately 800 million years ago, the levels of oxygen attained about 21 percent and started to breathe life into more composite species. The oxygen-rich ozone layer was also created, protecting the surface of the Earth from the harmful solar radiation.
<span>Primitive, single-celled life forms without organized nuclei are termed PROKARYOTES.</span>
Answer:
B.
Explanation:
Because a Longitudinal wave is a wave vibrating in the direction of propagation.
Grapes are a healthier choice because THEY PROVIDE FIBERS AND PHYTOCHEMICALS.
Grapes are natural fruits which possess more nutrients and beneficial components much more than manufactured artificial drinks. Fruits have fibers which purge one's system and make it easier for one to eliminate wastes, it also have a lot of natural phytochemicals that have beneficial effects on human system.
