Answer:
Statement C is the only one that is necessarily true for exons 2 and 3. It is also true for exons 7 and 8. While statements A and B could be true, they don’thave to be. Because the protein sequence is the same in segments of the mRNA that correspond to exons 1 and 10, neither choice of alternative exons (2 versus 3, or 7 versus 8) can alter the reading frame. To maintain the normal reading frame—whatever that is—the alternative exons must have a number of nucleotides that when divided by 3 (the number of nucleotides in a codon) give the same remainder. Since the sequence of the a-tropomyosin gene is known, it is possible to check to see the actual state of affairs. Exons 2 and 3 both contain the same number of nucleotides, 126, which is divisible by 3 with no remainder.
Human migration is the movement over long distances, movement from one country/region to another ) by people . Humans moved because of the c<span>hanging climate and landscape and inadequate food supply. </span>The first human movement was t<span>he movement of </span>Homo erectus<span> out of Africa across </span>Eurasia<span> about 1.75 million years ago. </span>
Than industrialization<span> encouraged migration wherever it appeared.
Wars also created migration. (</span><span>The First and Second World Wars, and wars, genocides, and crises sparked by them, lead to migrations).</span>
