Dichotmous Lab Report
Organismic Lab
Lab1- Dichotomous Key
Introduction A dichotomous key is a series of paired statements or questions that are used to categorize organisms with their similarities in characteristics and or structure. The word dichotomous comes from two Greek words that translate to “divided in two parts.” In a Dichotomous key each step has two choices: whether a particular characteristic is present or absent. The questions are arranged into a couplet which directs to another couplet and the process is repeated until a successful identification is reached. Qualitative descriptions refer to physical attributes such as scent or color, and quantitative descriptions refer to numerical values such as the amount of pedals on a flower. When constructing a dichotomous key, it is important that the questions are very clear and specific so that any two people that use the key will finish the key with the same conclusion. The purpose of this experiment is to demonstrate the use and know how to create a dichotomous key.
Materials
1 metric ruler
4 soy beans
4 mung beans
4 kidney beans li '
Fig 4 Wrinkled pea seeds Fig 5. Mung bean seeds Fig 6. Sweet Corn seeds
Fig7. Wheat Seeds Fig8. Soy bean seeds
Discussion Our group was successful in creating dichotomous keys in part A and part B. In part A, the dichotomous key will lead any two users to identify the same smiley faces. The dichotomous key of the seeds were to be much more difficult in classifying and separating than the smiley faces because the seeds did not have many simple physical differences like the ones found in the different smiley faces. The first physical difference identified divided the seeds into two different subsets: round and not round. Although identifying seeds as round or not round could differ from person to person, my group agreed that
Lab1- Dichotomous Key
Introduction A dichotomous key is a series of paired statements or questions that are used to categorize organisms with their similarities in characteristics and or structure. The word dichotomous comes from two Greek words that translate to “divided in two parts.” In a Dichotomous key each step has two choices: whether a particular characteristic is present or absent. The questions are arranged into a couplet which directs to another couplet and the process is repeated until a successful identification is reached. Qualitative descriptions refer to physical attributes such as scent or color, and quantitative descriptions refer to numerical values such as the amount of pedals on a flower. When constructing a dichotomous key, it is important that the questions are very clear and specific so that any two people that use the key will finish the key with the same conclusion. The purpose of this experiment is to demonstrate the use and know how to create a dichotomous key.
Materials
1 metric ruler
4 soy beans
4 mung beans
4 kidney beans li '
Fig 4 Wrinkled pea seeds Fig 5. Mung bean seeds Fig 6. Sweet Corn seeds
Fig7. Wheat Seeds Fig8. Soy bean seeds
Discussion Our group was successful in creating dichotomous keys in part A and part B. In part A, the dichotomous key will lead any two users to identify the same smiley faces. The dichotomous key of the seeds were to be much more difficult in classifying and separating than the smiley faces because the seeds did not have many simple physical differences like the ones found in the different smiley faces. The first physical difference identified divided the seeds into two different subsets: round and not round. Although identifying seeds as round or not round could differ from person to person, my group agreed that
References: http://oregonstate.edu/trees/dichotomous_key.html http://www.mhhe.com/biosci/pae/zoology/cladogram/ http://www.saskschools.ca/curr_content/biology20/unit3/unit3_mod1_les2.htm Lab Handout: 2002 Ward’s Natural Science Establishment