Science Assessment

Kelp is a type of algae. Algae are living things that are neither plants nor animals. Kelp live underwater, near the seashore. Like plants, kelp can make glucose through chemical reactions. When kelp grows, it gains mass.

Which of the following explains how kelp grows?

1. When kelp grows, new atoms are created, which become part of the kelp.
2. When kelp grows, it takes in atoms from its environment that become part of the kelp.
3. When kelp grows, it turns atoms from its environment into new types of atoms that become part of the kelp.
4. When kelp grows, its cells divide and no additional atoms are needed.