Answer: alpha
Explanation: Alpha particles are fast moving streams of positively charged particles that are shown to be Helium nuclei. They have a mass
number of 4 and an atomic number of 2 and a charge of +2. Alpha particles are represented as 4He2. When 238U92 becomes 234Th90, it emitted a helium nucleus 4He2. The equation for the decay is 238U92 ---> 234Th90 + 4He2.
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>
Bacteria have been the very first organisms to live on earth in the waters of the first oceans. At first, there were only anaerobic heterotrophic bacteria.
I think it’s C or A I’m not sure
