Katie wants to make ball-and-stick models of the four macromolecules. she has colored balls for each of the elements in these molecules, including the following. red: hydrogen black: carbon purple: oxygen green: nitrogen in which macromolecule will she use the black, red, and purple balls in a ratio of 1: 2: 1?

Explain how ancient whale fossils found in eqypt are believed to support the theory of evolution.

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.

The table shows dates and appearance of index fossils. which rock layers can be dated most precisely? a) a layer containing both a fossil 4 and a fossil 3 b) a layer containing both a fossil 2 and a fossil 3 c) a layer containing both a fossil 1 and a fossil 4 d) a layer containing both a fossil 1 and a fossil 2