Answer: alternative D.
Explanation: For the DNA to have the double strand structure, it is necessary to copy the sequence of the existing DNA strand in a complementary sequence of nucleotides, forming hydrogen bonds between them. The mRNA also uses this strategy when reading the DNA strand during the transcription, in order for the translation to begin.
Answer:
C) Meiosis
Explanation:
Alleles undergo segregation during the process of meiosis.
<span> </span>Stars<span> are formed in clouds of gas and dust, known as nebulae. Nuclear reactions at the centre (or core) of </span>stars<span> provides enough energy to make them shine brightly for many years. The exact lifetime of a </span>star<span> depends very much on its size. I hope that answers your question. :)</span>
Cells, tissue, organs, organ systems