The three main worm phyla are flatworms, roundworms, and segmented worms. Roundworms have a digestive tube that has two openings. Segmented worms have a closed circulatory system in which blood is enclosed in blood vessels. These are important steps in the evolutionary development of animals.
Explanation:
Igneous rock can form underground, where the magma cools slowly. Or, igneous rock can form above ground, where the magma cools quickly. When it pours out on Earth's surface, magma is called lava. In this way, igneous rock can become sedimentary rock.
Any rock (igneous, sedimentary, or metamorphic) can become a metamorphic rock. If rocks are buried deep in the Earth at high temperatures and pressures, they form new minerals and textures all without melting. If melting occurs, magma is formed, starting the rock cycle all over again.
Answer:
Explanation:
The reproductive system is different from other body systems in that the reproductive system functions in the survival of a species while all other body systems function to ensure the survival of the individual.