Download Unit Plan - O. Henry Science

Unit Plan
Day
Activity
1
Using and creating dichotomous keys
2
Collection of samples, sketching
3
Classification of organisms
4
Create keys for samples collected
5
Presentations, groups share and use keys
Assessments
Pre-assessment: Individual and group brainstorm and response to conceptual questions.
Post: Small-group presentations.
Materials
Key demo activity
Salamander dichotomous key handout (source: Prentice Hall, Biology)
Imaginary creatures dichotomous key handout
Plant dichotomous key website:
http://webworldwonders.firn.edu/cameras/keys/sa/tree.html
Alien dichotomous key website: http://biologyjunction.com/alien_invasion.htm
Rulers, composition books, compasses, stakes, meter sticks, poisonous plant guide,
collection jars, cameras, art supplies for drawing, large paper/poster boards, large post-it
notes, poster stands, masking tape, push-pins, etc to set up posters.
Day 1: Using and Creating Dichotomous Keys
Objectives
Students will be able to:

Use a dichotomous key to identify different types of plants or animals

Create a dichotomous key
Assessment
Lab activity with questions, online or written key activities
Standards

8.1L.1 Explain how genetics and anatomical characteristics are used to classify
organisms and infer evolutionary relationships.
Duration
1 hour
Materials
Key demo activity
Rulers
Salamander dichotomous key handout (source: Prentice Hall, Biology)
Imaginary creatures dichotomous key handout
Plant dichotomous key website:
http://webworldwonders.firn.edu/cameras/keys/sa/tree.html
Alien dichotomous key website: http://biologyjunction.com/alien_invasion.htm
Beginning
Pre-assessment questions (display). Give students a couple of minutes to think about these
questions, and then share their answers and brainstorm with their table groups. Then,
record the group responses.
1. Suppose you discovered a plant or animal you had never seen before - how would
you figure out what it is?
2. How would a scientist be able to tell if they discovered a new species?
Demo: How to make a dichotomous key. (attached)
After the demo activity, give an full explanation dichotomous keys: The word dichotomous
comes from the word dichotomy, meaning “two opposite parts or categories.” A
dichotomous key gives the reader a series of opposing descriptions of basic features of an
organism. We study the specimen and select the descriptions that apply to it until reaching
a statement that characterizes only one species and names it. In this investigation, students
will use a dichotomous key to identify the genus and species of several different
salamanders. Alternatively, students may use an online key to identify plants. Then, they
will create their own dichotomous key to categorize a group of different imaginary
creatures. For differentiation, this can also be done on paper or online.
Middle – Central Activity
Part I: Using a dichotomous key (salamander key or online plant key)
Pre-Lab discussion questions (display and read aloud)
1. How many choices does a dichotomous key provide at each step?
There are two choices at each step.
2. What are some of the apparent differences among the salamanders illustrated?
The size, color, shape, numbers and patterns of spots, and the presence or absence of
external gills are differences.
3. Based on the information in Figure 2, what is a distinguishing characteristic of the
members of the genus Ambystoma?
They all have a body coloring pattern with a black background and variable white spots.
Lab instructions (display and read aloud)
Use the dichotomous key to determine the genus and species of each salamander. Begin by
reading statements 1a and 1b. One of the statements describes the salamander; the other
statement does not. Follow the directions for the statement that applies to that salamander
and continue following the correct statements until you have identified it. Record the
scientific and common name of the salamander on the line next to each picture.
Part II: Making a dichotomous key (Imaginary creatures key or online alien key)
Using the imaginary creatures handout, students can now make a key.
Instructions: First, name each creature on the sheet. Then, identify features of each
creature that can be used to identify it. Create your key so that each line only describes one
feature.
End
Discussion
Compare and contrast the keys that each group made for the imaginary creatures. Create a
list of names that everyone has for each picture.
Reflection
Key to the Salamanders
1
2
3
4
a
Hind limbs absent
Siren
b
Hind limbs present
Go to 2
a
External gills present in adults
Mud puppy
b
External gills absent in adults
Go to 3
a
Large size (over 7 cm long)
Go to 4
b
Small size (under 7 cm long)
Go to 5
Body background black, large white spots irregular in shape and size
Tiger
completely covering body & tail
salamander
Body background black, small, round, white spots in a row along each
Spotted
side from eye to tip of tail
Salamander
a
Body background black with white spots
Go to 6
b
Body background light color with dark spots and or lines on body
Go to 7
Small white spots on a black background in a row along each side from
Jefferson
head to tip of tail
salamander
Small white spots on a scattered throughout a black background from
Slimy
head to tip of tail
salamander
a
b
5
6
a
b
7
a
b
8
a
b
9
a
b
10
a
b
Large irregular black spots on a light background extending from head to Marbled
tip of tail
salamander
No large irregular black spots on a light background
Go to 8
Round spots scattered along back and sides of body, tail flattened like a
tadpole
Without round spots and tail not flattened like a tadpole
Newt
Go to 9
Two dark lines bordering a broad, light mid-dorsal stripe with a narrow Two-lined
median dark line extending from the head onto the tail
salamander
Without two dark lines running the length of the body
Go to 10
A light stripe running the length of the body and bordered by dark
Red-backed
pigment extending downward on the sides
salamander
A light stripe extending the length of the body, a marked constriction at
Four-toed
the base of the tail
salamander
Name: ________________________________
Create a dichotomous key
Instructions:
1. Name each creature.
2. Identify features of the creatures that can be used to identify them.
3. Create a key so that each line only describes one creature feature.
Day 2: Diversity of Life - Transect
Objectives
Students will be able to:

Make systematic observations of organisms found in specified locations.
Assessment
Data measurement and recording, field collection, diagrams of plant or animal life.
Standards

8.3S.1 Based on observations and science principles, propose questions or
hypotheses that can be examined through scientific investigation. Design and
conduct a scientific investigation that uses appropriate tools, techniques,
independent and dependent variables, and controls to collect relevant data.
Duration
1 hour
Materials
Composition books, compasses, stakes, meter sticks, poisonous plant guide, collection jars.
Beginning
Probing questions for discussion: How many different kinds of organisms live in our area?
How can we find out or measure this? What are some of the organisms that live in our
area? What kind of data should be collected?
Discuss the value of life and the humane and respectful treatment of plants and animals.
Discuss poisonous plants such as poison oak that may be found in the area. Students
should carry a guide with illustrations of plants to avoid. Provide instructions for what to
do if a student touches a poisonous plant or is injured, bitten, stung.
Middle – Central Activity
In class:
Organize students into groups of three. Student A will measure his/her normal walking
step using the meter stick and records the distance. Each group then calculates how many
steps will be required to approximate 25 meters. Student B should be familiar with the use
of a compass and his/her role is to make sure the students move in a straight line based on
the direction provided by the teacher for the placement of the second stake. All students
should collect data, but student C makes the master list.
In the field:
Designate where the starting stake for each group will be placed and assign the heading
that the students will walk from the stake. Student A will step off approximately 25 meters
in the direction that Student B indicates. The end stake is placed at this point. The distance
between the two stakes for each group should be approximately the same. Before starting,
students should make general observations of the area: time of day, soil kind and color,
shade, sun, presence of streams or ponds, temperature, etc. Beginning at the starting stakes
students will slowly walk toward the end stake noting each kind of living thing: plant,
animal, fungus, lichen, etc they see. Birds that they hear but don't see are to be included.
Students are to count only one of each kind of organism (known or unknown) found on the
observation line between the two stakes. The width of the observation line between the
two stakes should be kept as narrow as possible. Use the width of a student ruler as a
guide. On each student should sketch each organism collected. If digital cameras are
available, pictures of unknown plants and animals can be taken. Collecting samples of
unknown plants, leaves, or flowers should be encouraged if appropriate. Collecting
invertebrate samples should be encouraged if appropriate.
End
Prepare class for day 3: Tomorrow we will be attempting to group and describe the
organisms we collected. We will create dichotomous keys for one group or category
(plants, animals, fungi, lichen)
Reflection
Day 3: Classification of Organisms
Objectives
Students will be able to:

Organize observed organisms into groups: plant, animal, fungi, and lichen.
Assessment
Students will group collected organisms into categories, make diagrams and data displays.
Standards

8.3S.1 Based on observations and science principles, propose questions or
hypotheses that can be examined through scientific investigation. Design and
conduct a scientific investigation that uses appropriate tools, techniques,
independent and dependent variables, and controls to collect relevant data.

8.3S.2 Organize, display, and analyze relevant data, construct an evidence-based
explanation of the results of a scientific investigation, and communicate the
conclusions including possible sources of error. Suggest new investigations based
on analysis of results.
Duration
1 hour
Materials
Composition books, cameras, art supplies for drawing
Beginning
Start by sharing class data, for instance the total number of organisms found. Today, we
will be determining the number of organisms in each group: plants, animals, fungi, and
lichen. Student groups will be starting their presentations for the unit, which will take
place on day 5.
Middle – Central Activity
Students will work in their groups to organize and classify the organisms they collected. In
their composition books, they should create four different categories for plants, animals,
fungi, and lichen with their sketches (from day 2) for each sample. Help them decide on an
appropriate data display (e.g., a pie chart) to show the total number of organisms found for
each group, types of organisms, and the relative numbers of organisms from each category.
Each group should then focus on one of the categories for their final project (due day 5).
This might be the category for which they have the most samples or for which they have
the most interesting samples. Students can either draw diagrams, or take and print
pictures for the organisms from their chosen category. Each picture should be
accompanied by a brief written description. The student groups can start work on a
presentation poster which will include appropriate graphs, collected plant material, digital
pictures etc.
End
Discuss differences in data for each group. What did the students learn about biological
diversity from this project? What other questions could we answer using this type of data
collection?
Tomorrow we will be creating dichotomous keys for our focus categories.
Reflection
Day 4: Creating Dichotomous Keys
Objectives
Students will be able to:

Create a dichotomous key using specimens.
Assessment
Students will create a dichotomous key based on the organisms they have collected and
classification schemes they determined in the previous lesson.
Standards

8.1L.1 Explain how genetics and anatomical characteristics are used to classify
organisms and infer evolutionary relationships.

5A/H5** (SFAA) A classification system is a framework created by scientists for
describing the vast diversity of organisms, indicating the degree of relatedness
between organisms, and framing research questions.
Duration
1 hour
Materials
Composition books, large paper/poster boards, notes from previous days, art supplies for
drawing.
Beginning
Take a few minutes to remind students of the key features of a dichotomous key. Ask them
a few questions to jog their memories (display and read aloud).
1. How many choices does a dichotomous key provide at each step?
There are two choices at each step.
2. What is one question you could ask to distinguish between a Maple Tree and a Pine
Tree?
Does it have needles?
Middle – Central Activity
Students will work in their groups to create a dichotomous key for the organisms they
collected (in their chosen category). The students will be given the following guidelines
(instructions will be given verbally and in written form).
Create a dichotomous key for the organisms you collected. Your key can be in any format
you choose, but it should include the following:

Clearly written (or drawn) criteria for each choice

A distinct way to identify EVERY organism included in your focus category.

Give each organism a unique name and include the names on your key.

Challenge - if you have time, try to minimize the number of steps necessary
to identify every organism on your list.
Test your keys by playing "dichotomous questions" with your partners. Have one person
choose an organism from your set. Ask them questions by following the dichotomous key.
See if you end up at the organism they chose.
End
Students will continue working on their posters and preparing for their poster
presentations. Students should label each organism on their posters using the names they
created for their dichotomous keys.
Reflection
Day 5: Presentations
Objectives
Students will be able to:

Present information about the organisms they have collected using a poster to
display data in an organized fashion.

Verbally explain the methodology they used to characterize and classify their
organisms.

Use their classmates' dichotomous keys to identify various organisms.
Assessment
Students will present posters and dichotomous keys to their peers (and the teacher). They
will be asked to complete a self-assessment, as well as a peer assessment, about the quality
of their presentations. (See below)
Standards

8.3S.2 Organize, display, and analyze relevant data, construct an evidence-based
explanation of the results of a scientific investigation, and communicate the
conclusions including possible sources of error. Suggest new investigations based
on analysis of results.
Duration
1 hour
Materials
Art supplies for drawing, large post-it notes, poster stands (masking tape, push-pins, etc to
set up posters).
Beginning
Give students 15 minutes to finish working on their posters. Have them use post-it notes to
cover the names of the organisms on their posters. They should include a copy of their
dichotomous key in their presentation. Have students post their posters in a "circle"
around the classroom, and number the groups.
Middle – Central Activity
Students will present their posters in a "poster session" format. Students will rotate
through the posters in two 15 minute long sessions. Students will be split into two groups
During the first session student A from each group and student B from the odd numbered
groups will present their posters. Student B from the even number groups and student C
from each group will rotate through the poster session. Have students rotate clockwise
around the room so that every poster has viewers. Students should fill out an evaluation
form for each poster they view - they should view at least 3 posters. After 15 minutes,
viewers and presenters will switch roles.
End
Give students time to complete their self-evaluations. They should turn these in before
they leave.
Reflection