Answer:
The answer is number two extinction happened, this was the time dinosaurs went extinct ebcause lack of sun because oh how much dirt was blown into the earth atmosphere becuase of the asteriod, third option is talking about big bang theroy so that dosnt apply!
Explanation:
Answer:
B) sympathetic nervous system
Explanation:
The sympathetic nervous system controls the way the body quick involuntary response to harmful or stressful situations. A rush in hormones rapidly occur to quicken the body's alertness and heart rate to release extra blood to the muscles
It's route of Expression starts with the amygdala sending a distress signal to the hypothalamus which sends activation signals to the sympathetic nervous system via the autonomic nerves to the adrenal glands which help pump the hormone epinephrine (also known as adrenaline) into the bloodstream.
Calcium is a chemical element with symbol Ca and atomic number 20. Calcium is a soft gray Group 2 alkaline earth metal, fifth-most-abundant element by mass in the Earth's crust. The ion Ca2+ is also the fifth-most-abundant dissolved ion in seawater by both molarity and mass, after sodium, chloride, magnesium, and sulfate.[5] Free calcium metal is too reactive to occur in nature. Calcium is produced in supernova nucleosynthesis.
Answer:
A DNA molecule produced by combining DNA from different sources is known as recombinant DNA.
Explanation:
Recombinant DNA (rDNA) can be obtained by coupling DNA fragments from different sources, a process that is performed at the restriction site level and uses enzymes.
Once rDNA has been designed —cutting out fragments of DNA that are then reassembled— it must be brought to a specific location in the cells, to be copied and expressed, using means of transport called vectors.
<u>DNA recombination</u> is performed in biotechnology laboratories specialized in the manipulation of genetic material.
The other options are not correct because:
- <u><em>Mutant or mutated DNA</em></u><em> is a DNA molecule with an alteration of its nitrogenous base sequence
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- <u><em>Hybrid DNA</em></u><em> is a variant of recombiant DNA, in which only two DNA molecules from different sources are used.
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- <u><em>Polyploid</em></u><em> refers to cells containing the genome of different species.</em>
