lab Dichotomous key
Identify question: How can we correctly identify unknown specimens
Back ground: A dichotomous key is a tool that allows the user to determine the identity of items in the natural world such as trees wildflower mammals reptiles rock and fish key consist of a series of either or choices that lead the user to the correct name of a given item dichotomous mean divided into two part therefore dichotomous key always give two choices in each step
Hypothesis: If the dichotomous key accurately describe the organism being identified. Then the characteristic of a particular species will appropriately match the dichotomous
Independent variable:
Dependent Variable:
Control variables:
Control variable# 1
Control variable # 2
Control variable #3
Material: .lab paper .Pen and pencil
.Specimen card and diagram
Procedure: 1.Use the diagram of laboratory equipment on page 3 to separate the type of equipment into 2 group
2. Record the characteristic used to separate the group on the diagram handout.
3. Continue to form subgroup within your two group base on different characteristic and record them on your diagram until you have only one piece of equipment in each group
4. Using the diagram you have made make a dichotomous key for the laboratory equipment. Remember each numbered step numbered step should contain two choices for classification
Collect and organize data:
Analyze data: I obtained fish specimens recorded there number and formed separate hypotheses for each specimen I used the dichotomous key to identify each specimen
Conclusion: The dichotomous key determine what teach studied specimen happen to be the characteristics of the particular organism and the environment in which is live
Further investigation: The dichotomous key help us in everyday life to identify unknown organism the purpose of a dichotomous key is to take an organism, say a comfier tree, and make note of its features and then look at a dichotomous key to identify what species it is based on its features
Post Lab question: How will this help us in everyday life?

1a. Body noticeably covered with scales
2
1b. Scales not covering body or too small to be seen
12
2a. Dorsal fin single
3
2b. Dorsal fins two or more, joined or separated
6
3a. Body more than four times as long as broad (top to bottom): front edge of dorsal fin far back on body; mouth large, hinge back of eye
4
3b. Body less than four times as long as broad: front edge of dorsal fin about midway between head and tail; mouth not large, hinge in front of eye
5
4a. Dark lines forming netted design on body: fins not spotted pickerel 4b. Body covered with yellow spots; fins spotted

Northern pike
5a. Mouth turned downward: barbels absent; dorsal fin not elongated
White sucker
5b. Mouth not turned downward: barbels present; dorsal fin elongated carp 6a. Two dorsal fins separated, the anterior spiny and the posterior soft
7
6b. Two dorsal fins united, forming an anterior spiny portion and a posterior soft portion
8
7a. Top of head concave, farming a hump in front of dorsal fin; dark vertical bars on body
Yellow perch
7b. Top of head not concave, body sloping to dorsal fin and not forming a hump; dark blotches on body walleye 8a. Body more than three times as long as broad
9
8b. Body less than three times as long as broad
10
9a. Hinge of jaws behind the eye: notch between spiny and soft dorsal fin deep and nearly separating into two fins
Large mouthed bass
9b. Hinge of jaws below the eye; notch between spiny and soft dorsal fin not nearly separating into two fins
Small mouthed bass
10a. Mouth large, hinge below or behind eye
11
10b. Mouth small, hinge in front of eye bluegill 11a. Five to seven spines in dorsal fin; dark spots forming broad vertical bars on sides, Red/orange ear spot on gill covering pumpkinseed 11b. Ten or more spines in dorsal fin: sides flecked with dark spots
Rock bass
12a. Body much elongated and snakelike: dorsal, caudal, and anal fins continuous
American