They must find food
they must find shelter
Discontinuous variable ;)
Facilitated diffusion therefore allows polar and charged molecules, such as carbohydrates, amino acids, nucleosides, and ions, to cross the plasma membrane. Two classes of proteins that mediate facilitated diffusion are generally distinguished: carrier proteins and channel proteins.
Answer:
Explanation:
1st pic:
movement of the two land masses are towards each other but no subduction so the ans is b. collisional
2nd pic:
subduction occurs so it is c. convergent boundary
Commensal bacteria are friendly bacteria in the large intestine.
These bacteria produce Vitamin K and Biotin (a B Vitamin). The bacteria may be
a source of these vitamins, but if a person depends solely on the bacteria for
these vitamins, the person may become vitamin-deficient especially if they are
treated with antibiotics that can kill commensal bacteria.