PLEASE HELP!! If the sperm cell is unable to enter the egg cell when they meet, this is which of the following reproductive barriers? A. posy-zygotic isolation B. temporal isolation C. gametic isolation D. mechanical isolation​

Cancer cells spread to other parts of the body by entering the bloodstream. which of the following organs could prevent a cancer cell in the bloodstream from spreading, and why? a. the spleen, because it releases lymphocytes into the blood b. the peyer's patches, because they release lymphocytes into the blood c. the lymph nodes, because they release lymph into the blood d. the thymus, because it releases lymph into the blood