Calcium is a substance found in vitamins that people take to help strengthen their bones and teeth.
Which plant has been used for a similar purpose?
ferns
horsetails
liverworts
club mosses

2. which of the following statements does not accurately describe stem cells? a. embryonic stem cells make up the inner cell mass of a blastocyst. b. with more research, stem cells may be used to repair or replace damaged cells. c. the use of stem cells is without any objections since it can be used in therapies to humans. d. adult stem cells are multipotent and can differentiate into many types of cells.