20. Proteins

Meat is one of the many foods that contain protein. Protein is a molecule composed of amino acids linked together in a particular order specified by a gene's DNA sequence. Proteins perform a wide variety of functions in the cell, including serving as enzymes, structural components, or signaling molecules.

19. Redox Reaction

This is rusting iron which displays a redox reaction. A redox reaction is where the atoms in a chemical reaction change their oxidation numbers and there is a loss of electrons resulting in rust.

18. Seed Dispersal

Seed dispersal is the movement or transport of seeds away from the parent plant. Plants have limited mobility and rely upon a variety of ways to disperse its seeds. These include water, wind, and even animals. This pine cone contains seeds in which will eventually disperse to create a new tree.

17. Niche

A niche is the role a particular species plays in its environment and how it can adapt to its surroundings. This is a bird nest located by my pool. Although this is not a usual place for a bird nest to be, it shows how the birds adapted to their environment using the natural surroundings.

16. Long Day Plant

This Iris plant is an example of a long day plant. A long day plant is stimulated by short nights to induce flowering in the spring.

15. Homeostasis

This is John and he is maintaining homeostasis. Homeostasis is the ability of a living organism to maintain an internal equilibrium despite external conditions. His body temperature remains constant while the heat outside is constantly changing.

14. Frond

Frond is the term used to describe the branch and leaf structure of a fern or members of the palm family. This plant is made up of big compound leaves which apply to those of palms.

13. Ethylene

Ethylene is a colorless gas with a sweet ether-like odor that is produced by many fruits and vegetables. It is a hormone that accelerates the ripening of many fruits. This picture is of a very ripe mango.

12. Epethelial Tissue

This picture is an arm which displays epithelial tissue. Epithelial tissue contains cells in animals that are closely packed in either single or multiple layers, and which cover both internal and external surfaces of the animal. It forms an outer layer of body surface such as skin.

11. Autotroph

An autotroph is an organism that is capable of producing complex organic compounds from simple inorganic molecules using energy from light (by photosynthesis) or inorganic chemical reactions. This is a picture of a dandelion which undergoes the process of photosynthesis to produce its own nutrients.