Answer:
It is called the S-A node, or rather sinus node.
<span>The male reproductive parts of a flower is the stamens which are comprised of the anther (which produces pollen) and the filament which supports the anther. The primary purpose of the stamen is to produce pollen which is used to fertilize the female parts of the flower (typically another flower from the same species of plant, but it is possible for some plants to be self fertilizing).</span>
Answer: 1. CCGTAAGCGCTAGTAC
2.GCAATCGTACGAAGTA
3. TGATTGCCATCGATCG
Explanation: you just flip the letters with their corresponding ones
The answer is Walter Hess
Hess manipulated the diancephalon of the brain of cats by inserting metal rods in the hypothalamus regions of the brain, where the diencephalon is located, and passing electrical current through the rods to the brain region. He noticed that the cats, among other complex behavioral changes, would curl up and sleep.
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.
