The Colorado River has been forming the Grand Canyon in Arizona for at least 6 million years. During this time, the river has slowly caused erosion of the rock. As the rock eroded, soil eroded as well, and plant populations have had to adapt to live in increasingly rocky conditions. The river continues to deepen and erode the canyon at a rate of a few milimeters per year. What geologic principle is this an example of?

Complete the sentences by matching the names of trees to the appropriate blanks. to do this, drag the names on the left into the appropriate blanks in the sentences on the right. match the words in the left column to the appropriate blanks in the sentences on the right. terms may be used more than once. make certain you have filled every blank with a term before clicking submit. 1. deciduous trees lose their leaves seasonally and include trees such as maple and elm. 2. conifer leaves are generally thin and needle-like, while seeds are contained in cones. conifers include cedar and pine. 3. evergreens are plants that maintain their leaves in all seasons and include trees such as cedar, elm, and pine. 4. hardwoods reproduce using flowers and have broad leaves; hardwoods include trees such as maple, , and cedar. elm returned you filled in 2 of 10 blanks incorrectly. mango trees are tropical broad leaf plants that maintain their leaves all year long. no credit lost. try again.

Compare and contrast cladistics and phylogeny. what are their advantages and disadvantages? which is the most useful in understanding how an organism developed into its current form? which concept most strongly supports your opinion about the origin of any given organism?

Which layer of the eye completely surrounds the eye except for a dark, round opening called the pupil? a. sclerab. corneac. retinad. choroidthe answer is a sclera