The kitties demonstrate genetic variation within a population in that the fur color and eye colors are different for the cats. Cats have various blood types, evidence of multiple phenotypes (traits determined by genetic makeup). So these cats show genetic variation on the outside and inside.


The guinea pig is a eukaryote because it has eukaryotic cells in that the cells have membrane-enclosed nuclei and membrane-enclosed organelles.


The little green birdie is an endotherm because its bodily heat comes from metabolism and is relatively stable and warmer than its external environment.


The itty bitty lizard on the wodden thingie is an ectotherm in that most of its bodily heat is derived from an external source.


This pineapple is another example of a CAM plant in that it closes its stomata during the day and opens at night to reduce water loss and carbon dioxide entering leaves.


A CAM plant, such as this cactus, closes its stomata during the day and opens it at night to reduce the amount of water loss during the day as well as prevent carbon dioxide from entering the leaves.


C4 plants begin the Calvin cycle with a carbon fixation that forms a four-carbon compound as its first product, and corn is a C4 plant.