Natural selection act directly upon <u>Alleles</u>
Explanation:
Genes, such as that of fur color, have many variants called alleles. Natural selection act on the alleles and chooses the best fit for an environment and eliminates the disadvantageous ones from the population over generations. Mutations are a rare occurrence that increases the number of allelic variants of a genes on which natural selection can act upon.
Answer:
C) are sequence-specific DNA endonucleases
Explanation:
Restriction enzymes represent a type enzyme capable of recognizing short nucleotide sequences to cut at specific restriction sites in the DNA, these sites are known as target DNA sequences. Some of the most commonly used restriction enzymes are <em>EcoRI</em>, <em>BamHI</em> and <em>HindIII</em>, isolated from <em>Escherichia coli</em>, <em>Bacillus amyloliquefaciens</em> and <em>Haemophilus influenza</em>, respectively. Restriction enzymes are endonucleases because these enzymes only cleave the phosphodiester bond within the DNA chain, conversely to exonucleases, which cleave nucleotides from the end of the polynucleotide DNA strand.
Mitochondria
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