Unit 5 Individual Project Biology - Essay Example

The Dichotomous Key (Appendix B) was used to determine the taxonomic category (phylum or class) for each animal picture, and these categories written on Classification Column on the table. The phylum list (Appendix A) for each animal picture were also written in column one; and all steps on column two as used to arriving at the classification for each animal given. The cartilaginous Fish are in class chondricthyes for instance the rays and sharks. Their skeleton is made of cartilage and not the bone.

They do not have the lungs and swim bladders. The placodermi fishes are precursors of these fish that are now extinct. They were the first fish to develop paired fins and jaws. (Don, & DeeAnn, 2005). 6. The three types of mammals based on how the young one develops are marsupials, monotremes, and placentals. The monotremes lay eggs; marsupials give birth to underdeveloped young ones and develop them in a pouch such as the koala and kangaroo (Mayr, & Bock, 2002). The placental mammals give birth to adequately mature young ones, feed them via the placenta until they are fully developed in a womb before they are born (Mayr, & Bock, 2002).

An example is the humans. Dichotomous means “divided or cut into two parts.” A dichotomous key is a tool used by scientists to classify organisms into classification categories or taxa. The key is made up of a series of numbered couplets, and within each couplet are two opposing statements which you read, choosing the one that best fits the animal picture. To use the key, you always start at the first couplet (look for a 1 in the first column). Read the two couplet choices (labeled a and b in the second column), and consider them carefully.

If you do not know the meaning of a word, as some of these terms are technical, look them up in a reference, a dictionary, or your textbook glossary, perhaps. Again, you