<span>Gram-negative bacteria have a cell wall that is <u>thin</u> and does not accept the stain, making it appear <u>red or pink</u><u />. <u> </u>Gram staining is used for differentiation gram-positive from gram-negative bacteria based on the characteristic of their cell wall. Gram-negative bacteria have a thinner cell wall than gram-positive bacteria. In this staining, bacteria are first stained with crystal violet dye. Only gram-positive bacteria will be violet colored because they can retain the dye thanks to their cell wall. The second staining with fuchsine or safranin will give the red or pink color to the gram-negative bacteria. <u> </u></span>
<span>This variation be justified by: </span>Migration to an environment different from their birthplace, and adaptation to the available food, ultimately leading to speciation. because <span>birds use their beaks to eat.</span>.
Melanin helps the mouse survive because of the fur color. Its color helps it to blend into its surroundings, making it a lot harder for predators to kill it, as the predators have a harder time seeing the mouse.