Select the best explanation of how a t cell uses either cell-to-cell contact or chemical signaling to enhance the activities of the immune system.1. chemicals called cytokines are secreted from t cells to signal production of antibodies by b cells.2. the t cell stimulates the antigen-presenting cell to release chemicals called cytokines to stimulate the cytotoxic t cells.3. the second exposure of the antigen causes the t cell to activate memory t cells.4. the pathogen is engulfed by a t cell and its antigenic markers are displayed on its surface.

The accompanying figure shows the percent of selected dna sequences that match between a chimpanzee and other primates. these data support the hypothesis that the figure shows the percentage of selected d n a sequences that match between the chimpanzee and other primates. the human has an almost 98 percent match, the gorilla has an almost 97 percent match, the orangutan has a 96 percent match, the gibbon has an almost 95 percent match, and the old world monkey has an almost 92 percent match. the accompanying figure shows the percent of selected dna sequences that match between a chimpanzee and other primates. these data support the hypothesis that the figure shows the percentage of selected d n a sequences that match between the chimpanzee and other primates. the human has an almost 98 percent match, the gorilla has an almost 97 percent match, the orangutan has a 96 percent match, the gibbon has an almost 95 percent match, and the old world monkey has an almost 92 percent match. chimpanzees and gibbons are the most closely related the chimpanzee's closest surviving relative is humans orangutans are the primates least closely related to chimpanzees old world monkeys and gibbons are the most closely related

Donde se encuentra el adn nuclear en un organismo eucariota?

How does the nervous system affect the excretory system?