Scientists classify organisms into groups, usually with a dichotomous key. using a dichotomous key is like solving a puzzle, one in which you make choices about the organisms you are trying to classify. to classify this organism, you must complete the second tier of this dichotomous key. what would be the best choice for the second tier?
a) size of body
b) insect or sea creature
c) six legs or eight legs
d) two body segments or three body segments

Plants are used for so many things. in your house alone, you can probably look around you and see where plants have been used. for this project, you will identify various uses of plants in your home. directions make a list of objects, products, and any other items around your house where plants were involved in the production of the item. you should have a list of at least twenty items. then respond to the following questions: note: your list of objects and the answers following should be at least 200 words in length. what if plants no longer existed on earth? how would your life be different?

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

The phylogenetic tree illustrates the relationship between humans and our closest living relatives. the tree was based on biochemical comparisons, including dna and amino acid sequences. according to the biomolecular data, we could infer that a) the four organisms do not have a common ancestor. b) humans are more closely related to chimps than any other apes. c) chimps are more closely related to gorillas than they are to humans. eliminate d) there is no evidence if any relationship between the four branches on the tree.