Lab: Using a Dichotomous Key

Question 1

Use this dichotomous key for insect identification to identify the insect shown.1.a. Insect has one pair of wings.Order Diptera b. Insect has two pairs of wings.Go to #2 2.a. Front wings thicker in texture than hind wingsGo to #3. b. Front and hind wings are same texture throughout.Go to #4 3.a. Front wings are short Order Dermaptera b. Front wings cover entire abdomenOrder Coleoptera 4.a. Wings with scale on all parts of their area. order Lepidoptera b. Wings without scalesGo to #5. 5.a. Hind wings smaller than front wings.Order Ephemeroptera b. Front and hind wings nearly equal in size.Order OdonataThe insect pictured is in the order

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D: Odonata.

Question 2

Refer to this portion of a dichotomous key for fish identification to answer the question.1. (a) Has a single dorsal fin ® 5 (b) Has a double dorsal fin ® 25. (a) Has small fin on back near tail ® 6 (b) Has no fin on back near tail ® 76. (a) Has barbs near the mouth ® Catfish (b) Does not have barbs near the mouth ® 10What do the numbers after the arrows represent?

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A: the number of the question that should be considered next

Question 3

A botanist observes a large population of a particular type of beetle eating the leaves of one tree but not the leaves of a nearby tree. What should the botanist do first to study the interaction of these organisms in the ecosystem?

Revolt · Accepted Answer

B: Identify the species of the beetle and the species of both trees.

Question 4

Observations of organisms include

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B: descriptions of the number, size, and arrangement of parts of the organism.

Question 5

A series of choices between two characteristics that is used to identify organisms is called a

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D: dichotomous key.

Question 6

Dichotomous keys ask

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D: yes-or-no questions about easily observable characteristics.

Question 7

A biologist is using a dichotomous key to identify fish.1. (a) Has a single dorsal fin ® 5 (b) Has a double dorsal fin ® 22. (a) One fin is spiny, the other is smooth ® 3 (b) One fin is not spiny or smooth ® 45. (a) Has small fin on back near tail ® 6 (b) Has no fin on back near tail ® 76. (a) Has barbs near the mouth ® Catfish (b) Does not have barbs near the mouth ® 107. (a) Tail is asymmetrical ® 8 (b) Tail is symmetrical ® 910. (a) Scales are small ® Trout (b) Scales are large ® WhitefishWhat is the next step to take to identify a fish that has a single dorsal fin and no fin on the back near the tail?

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C: step 7

Question 8

A scientist wants to study the interactions of different birds in the southern part of a desert. What should the scientist do first?

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C: Identify each bird species by using a dichotomous key.

Question 9

The mammal pictured below is a silvery mole rat.Which statement is an inference based on the picture?

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D: The animal likely has poor vision since its eyes are so small.

Question 10

Which best describes a dichotomous key?

Revolt · Accepted Answer

A: Each step has two choices.

Lab: Using a Dichotomous Key Answers

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