Big Idea 2

4: Autotrophs: Autotrophs are organisms that produce their own food. This plant uses light energy to synthesize its own food.

5: Cellulose: Cellulose is the main ingredient in a plant's cell walls. The above picture shows a plant, which has cellulose in its cell walls.

10: Cohesion of water: Cohesion is a property of water that shows that is molecules are attracted to themselves. This is the reason why the waterfall in the water feature in this picture does not break apart into many different droplets, but generally stays together as a whole.

12: Ectothermy: An ectotherm is an animal that cannot provide its own body heat. This blue-tongued skink cannot generate its own body heat.

13:Endothermy: Endotherms are animals that are able to produce their own body heat. This flock of flamingos can provide their own body heat, but have to roost together, because they lose it very quickly.

15: Enzyme: An enzyme is a macromolecule that modifies another molecule by adding or subtracting atoms, or by changing its shape. The enzymes used to make this yogurt made it thicker and more savory than its predecessor, milk.

16: Fermentation: Fermentation is the process by which an organism can produce electron donors in the absence of oxygen. In the beer above, yeast have fermented sugars into alcohol in order to extract electrons. This beer was made by yeast that fermented starches into alcohol.

17: Glycogen: Glycogen is an energy-storage unit in animals. It consists of multiple glucose molecules clumped together, and it is usually stored in muscles and the liver. These slices of bacon are bound to have some glycogen in them.

21: Hypertonic: A substance is hypertonic to another if they are less diluted than the substance it is being compared with. For example, the maple syrup here is hypertonic to the distilled water in my bottle.

22: Hypotonic: A substance is hypotonic to another if they are more diluted than the substance it is being compared with. For example, the distilled water here is hypertonic to the stir fry sauce.

28: Lactic acid: Lactic acid is the product of the energy cycle in humans in the absence of oxygen. This biker's muscles are already producing lactic acid, because he cannot breathe O2 in fast enough.

29: Long-day plants: The lettuce in this picture is a long-day plant. It flowers only when the length of the day exceeds a certain amount of time.

30: Phloem: Phloem is the tissue that carries sugars to any part of the plant that needs it. It is usually situated in the innermost bark layer of a tree. It is the white-ish region in this picture of celery.

32: Saturated fat: Saturated fats are fats whose carbon molecules form only single bonds with other carbon molecules. Because of this, they are usually solid. The cheese in the picture contains only saturated fats because it is solid at room temperature.

35: Territorial behavior: Territorial behavior is a kind of protective behavior that some animals have toward the are in which they live. This snow leopard is highly territorial about his den. He patrols his area relentlessly to protect himself and his area.

36: Transpiration: Transpiration is the process by which plants expel O2 and ingest CO2 using the stomata under their leaves.

38: Xylem: Xylem is the tissue in vascular plants that transports water and nutrients from the roots to the top of the plant. The best-known xylem tissue is wood.