Compared to separate sexes and assuming self fertilizing is not possible, what might be one advantage and one disadvantage to hermaphroditism ​

Elephants in the savanna regions of africa dig holes in dried up river beds to reach water lying just below the surface. these holes provide drinking water for other animals as well. so, without the elephants, many animals might otherwise die from lack of water during the dry season. the location in which the elephants live is an example of a/n and the role they play in creating water holes is an example of a a) ecosystem; habitat b) community; niche c) habitat; niche d) niche; habitat

The response is the basis for vaccination. primary secondary tertiary none of the above

Explain how paleontologists use trilobite fossils as index fossils for various geologic time periods.