1. earthquake measures
2. b
3. seismograph
The three principal organs of seed plants are roots, stems, and leaves. Roots: absorb water and dissolved nutrients. anchor plants in the ground.
A challenge to traditional (pre-1860) ideas about species came from embryology, when it was discovered that embryos of dissimilar organisms, such as sharks and humans, resemble each other. Embryology involves the study of the formation and the development of an embryo and the fetus. It is one type of evidence of evolution such that the embryos of many different kinds of animals, mammals, reptiles, birds, fish among others, are similar showing a common ancestry.