Which of the following is correct about the flatworm's muscular system ?
a. it's muscles are attached to a center bone.
b. it consists of two layers of muscle.
c. its muscles are all involuntary.
d. it contains three types of muscle tissue.

According to piaget, children have acquired the cognitive skill of conservation when they're able to a. understand that six ounces of liquid in a jar and six ounces in an elongated tube are equal. b. understand the viewpoint of other people. c. relate objects around them to their own needs. d. realize that the term heavy describes an object one way and the term big describes it another way. it is not b nor c. did this 2 x wrong..

According to the cladogram, which organisms have roundworms as a common ancestor?

Despite the differences in mature plant cells, all of them are derived from meristem cells. the three major types of tissue systems develop from the meristem. meristems develop cells in all but which tissue?