In this example, six populations are currently under study. Four out of the six populations can interbreed with one another and produce fertile, viable offspring. Two of the populations can only form fertile, viable offspring with members of their own population. According to the biological species concept, how many species are present in this example

Kidney stones are tiny crystals of calcium or magnesium that block the narrow sections of the excretory system. which symptoms would a person with kidney stones experience? a. inability to store urine; pain in the bladder b. inability to store urine; pain in the urethra c. reduced urine flow; pain in the bladder d. reduced urine flow; pain in the urethra