Genetics  Traits  MiniUnit
"The Human Family:  Appreciating Diversity"
A  Series  Telemation Lessons

SPECIAL NOTE ABOUT THIS UNIT: You presently have the ÒtextÓ 
version of this unit. Many of the charts referred to in this unit do not 
appear in this version of the unit. To take full advantage of the unit 
download the full version of this unit from www.mcn.org and use 
Microsoft Word for the Macintosh to read the unit.

Cory M. Wisnia

Mendocino  Middle  School

ÊCalifornia State Framework Areas: Science and Mathematics

Grade Level:  6-8
Length of Project:  3-4 weeks

Produced in conjunction with the NASA K-12 NREN Partner School 
Program and the California Telemation Project

I.  Introduction:

The study of human and plant genetic characteristics is important to an 
understanding of both genetics and evolution as biological science 
topics.  In this series of lessons,  participating classes study and seek to 
appreciate the wide diversity that exists among the human species,  in 
terms of physically observable traits.  Students also explore the 
existence of variation among vegetables.  These lessons were written 
and adapted from lessons produced by the California Science 
Implementation Network as part of Project Storyline.  They were a 
section of a unit called Adaptation and Variation,  co-written by Cory 
Wisnia in 1991-2.  These and other lessons are used each year by Mr. 
Wisnia in his 8th grade class and have been continually modified.  The 
modification that these lessons have now experienced is the expansion 
to use with distance learning and telecommunication through the 
internet.    After inviting other schools to join in this survey of human 
and plant diversity and variation  (schl.class.ideas and other resources 
for inviting),  classes first work independently to catalogue the range of 
phenotypes (physically observable genetic traits/characteristics) within 
their own group.  They begin to make inferences regarding certain 
traits,  as well as manipulate and evaluate their data.  Using several 
possible data display tools (ClarisWorks or Microsoft Word),  they then 
prepare their data for distance sharing.  Schools involved with this 
project then cross-evaluate partner school data, and compare it to their 
own. The possibility of video-conferencing to share unusual 
phenotypes over the net will be explored,  as will individual or group 
presentations of hypotheses for further study.   Inferences regarding 
traits versus national origins and other issues will be also explored 
with an eye to gaining more appreciation with respect to our own 
diversity as a species.  It will be the responsibility of participating 
schools to gather and organize the data needed and send it to our site 
for general dissemination.  Students at our school will help standardize 
the incoming data, and set up whole group data tables.  On a local level 
we will compare the group data to that of our own school community.  
Students will help decide conventions and define problematic issues 
where they arise,  helping other schools know what is meant by a 
particular trait or explaining exceptions and "outliers",  which may be 
used for special investigations.

Recent or current news articles will also be shared over the network,  
especially those haiving to do with gene therapy or the discovery of 
new genetic information regarding diseases or special traits.

Purpose:
To explore the remarkable diversity of the human species and compare 
and contrast similarities/differences among both human and plant 
species in terms of variation.  To allow students from separate sections 
of the country experience their basic similarities while appreciating 
these differences.  To meet students from cultures somewhat or 
remarkably different from their own.  To experience on-line sharing of 
data perhaps even video-conferencing as a presentation tool.

II.  Student Outcomes

See individual lessons under   "Key Concepts".  Also,  besides the 
science learning/process skills involved,  students will also be given 
opportunity to use and become familiar with the use of the internet as 
a tool for sharing information with schools quite distant from there 
own.  Every effort will be made to learn more about the schools and the 
communities involved with this project,  including setting up e-mail 
pen-pals, sending information about each school to the partners, etc.  In 
the past some schools have produced videos of their own design which 
give more insight into the types of communities and general school 
climate.

III.  Activities

The direct activites are listed under the three lessons included below.  
Additonal to this,  the following will proceed.

*  Make connection through usenet conferencing to other schools,  
inviting them to participate.  We will be looking for from 12 - 15 
schools,  not necessarily in California or even the US,  but will most 
probably keep the grade level at 8 or 7th and 8th grade,  depending on 
participation.

*  Each schools receives the full set of lessons,  charts and other 
information,  hopefully through the internet,  although those who 
have difficulty receiving or downloading attachments may receive a 
disc in the mail.  Timelines for the lessons will be set in the early fall.

*  Classes will do the series of three lessons, one at a time,  gathering 
class data for each.  There will be a break between lessons which will 
allow for not only those who need to catch up, but for sending in class 
data and disseminatong it outward.  

Prior to Week 1:
Schools chosen to participate;  lessons sent;  timelines set/calendars 
sent and modifications developed if needed.

Week 1:
Introduction to the first lesson,  Great Traits,  and a gathering other 
group information.
Week 2:
Sharing/receiving data from lesson one on-line;  begin Height/Span 
lesson, and students explore family traits of personal interest.
Week 3:
Sharing and receiving group data,  evaluate Great Trait data,  
learn/explore display methods;  begin Vegie Variation.
Week 4:
Data sharing, and evaluation;  on-line presentations including video if 
possible.

IV.   Assessment

Final assessment for the class will be the completion of a portfolio of 
personal and class investigations of human and plant genetic traits.  
The following items will appear in the portfolio.

*  Personal Gene Wheel,  as well as individual chart which includes 
special traits chosen for investigation.  Copies of the group projects 
worked upon,  including the display and evaluation of data both from 
their own class and at least one other school participant.  
Telecommunication journal entries with copies of e-mail sent to 
partner schools or particular students.  If video conferencing becomes a 
possibility,  this will be included as part of their assessment package.

Subconcepts for  Genetics Traits Mini-Unit


1.	There is a diversity of variation of inherited traits within a 
species which may be observed in individuals.
		Lessons:  
	Great Traits: Gene Wheel/Height & Span
		
		Vegie 
Variation
		
		

2.	Traits are passed from parent to offspring.
		Lesson:
	Family Tree/Gene Chart

Great Traits
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-----------------

 1.  Storylink:   Among populations  within a single species,  there are 
considerable  variations,  some of which may be easily observed.  
Variations among humans are rooted in the genetic characteristics of 
individuals,  and involve TRAITS which have been passed on to 
offsprings from their parents.  

2.  Overview:   This is an activity in which each student checks on 
which of a number of "likely/unlikely" traits he or she has,  then 
compares with other classmates.  These traits are all physical traits 
which have observable characteristics,  and which have been inherited 
from one or both of their parents.  

3.   Key Concepts: 
	1) Variations exist among humans,  some of which can be 
observed.
	2) Traits can be passed from parent to offspring.
	3) Some traits are more common than others.

4.   Grade Level: 6-8

5.   Advanced Preparation: Run off Trait Charts,  and Gene Wheels.  
Run off 6-7 copies trait drawings for groups to use.  Optional:  make an 
overhead transparency for both the wheel,  chart and for certain 
instructions.  

6.   Time: Two class periods

7.   Grouping Suggestions:   Self-determining of traits by students can be 
a whole-class process,  in which each trait is explored at one time.  
Graphing of traits may be done first in small groups, then compared 
with other groups,  then done as an entire class or groups of classes.  On 
the other hand,  graphing can simply be a whole class,  followed by a 
debriefing.

8.   Materials (per student or per class):   One Trait Chart & Gene Wheel 
per student.  6-8 Trait Drawings (one per table grouping).  Overhead 
transparencies for teacher use. 

9.   Thinking Processes:   Observing,  communicating,  comparing,  
inferring.

10.  Curriculum Connections:   Math








1. Teacher Background (includes vocabulary): 
Not all genetic traits can be seen,  in this lesson students will primarily 
learn about several traits which are visible.    For the teacher it is 
valuable to have a little background on first,  how to determine the 
trait itself.  Also,  there is a difference between whether a trait is 
Dominant or Recessive,  and whether it is more or less frequent in 
populations (see below under "teacher's background vocabulary" 
below).  For one of the charts that are used more or less likely is used 
instead of Dominant or Recessive.

Ear Lobes:  do the lobes hang or is the ear attached without hanging 
lobes?

Tongue Traits:  rolling means being able to flip the tongue all the way 
over.  Other recessive tongue traits are the inability to curl tongue,  
having tongue touch nose,  making a "ski tongue" or other unusual 
features!

Double Jointed Hands:  this can mean "witches fingers",  hitch hiker's 
thumb,  curving hands,  curling little fingers,  double jointed thumbs,  
etc.

Other Double Jointed:  Shoulder blades,  hips,  elbows or other unusual 
features...students will surprise you  (I've even seen strange stomach 
rolls)!

Thumb-Handedness:  have student simply put their hands together,  
interweaving their fingers.  Check which thumb is on top.  Since some 
students can't decide by this method,  then ask which index finger is on 
top.  That will be which thumb should also be on top.  After they have 
figured this out,  have them replace their hands together so that the 
opposite index finger is on top....This feels very strange!

Index (1st) Finger Length:  put hand on the edge of a piece of paper so 
that the middle finger is slightly above the edge and the 3rd finger of 
each hand is right on the edge.  Where is the index finger.  Dominant = 
even with the 3rd finger.  Are both hands dominant or both recessive 
or one of each?

Dominant Eye:  have students hold up their thumb with arm stretched 
out in front,  and look "through" it at a corner of the classroom or at a 
small object with both eyes open. Then first close the left eye,  then the 
right.  In most cases,  the thumb will appear to "shift"  with one eye 
open but appear to stay in place for the other eye.  The second case is 
the dominant eye.  If students have a hard time with this,  don't 
dispair:  this is hard to explain or do for some people.

Long second toe:  is the second toe longer than the toe "thumb"?  If this 
is so,  then this is the "less likely" trait.

Widow's Peak:  the hair line comes to a peak on the forehead.  It is not 
clear how "less or more likely" may relate to racial diversity.   Blood 
type:  students may not know their own blood types but their parents 
will.  If you use this trait,  understand that while "O"  is the "most 
likely"  trait  (approx.  60% in U.S.),  it is recessive.  A and B are 
dominant,  in that if a person has an "O" gene and a "A" gene,  they 
will be A type.  A mixed with B is AB,  which is the rarest type in the 
U.S.  There is no discussion here of "positive" or "negative" types,  
since it is too sophisticated at this grade level. (This characteristic is 
described here more for the teacher than the student since this is a 
fairly complicated concept).

Colorblindness:  this is a trait that is "sex-linked".  It is generally 
"carried" by the mother,  and shows up in the sons.  If a woman is 
colorblind,  her father must have been colorblind,  and her mother was 
at least a carrier.  If a man was colorblind,  he received the trait from his 
mother only.  Again,  this trait may bee too esoteric for 3rd grade or so,  
but it is good to know about (for you!).  Baldness is the same situation:  
carried by the mother,  expressed in the son.

Hitch-hikers Thumb:  this is a trait that will show up surprisingly 
often.  There are many well-known folks who show this trait.  The next 
time you see Jesse Jackson give his "thumbs up" sign for victory,  check 
out his great hitch-hikers thumb!!  The thumb for this trait bends far 
backwards at the knuckle,  in some cases forming almost a right angle.  

Some notes on vocabulary:   it is easy to confuse "most likely"  with 
Dominant,  and "least likely"  with Recessive,  but this is not always 
true.  For a trait to be Dominant,  it only takes 1 gene too result in the 
dominant characteristic.  Many times this will be the most likely to be 
seen,   but not always.   For example,  type A blood is dominant,  but in 
this country more than 50% of us have type O blood.  Many times  the 
dominant gene is seen more frequently.  But sometimes,  in special 
populations a recessive trait,  such as blue eyes will be the most likely 
to be seen.  A Recessive trait is one which needs 2 gene elleles,  one 
from each parent to be expressed,  in most cases.   An exception is "sex-
linked recessiveness".  In this case the gene is on the sex chromosome.  
In the case of a male,  the gene is on the x chromosome.  Since this 
chromosome is longer than the y chromosome,  there are some genes 
which have no pair.  If one of these is a Recessive trait,  it will be 
expressed even though there aren't two of them because there is no 
dominant gene to mask it.  This is how balness,  colorblindness,  and 
hemophilia are transmitted.  This last information goes well beyond 
the needs for this activity,  but may come up because of individual 
children's experiences.

Presently,  there is much research which is centered on how genetic 
traits,  including both disease-related susceptibilities and emotional 
characteristics may be identified and traced through family trees.  Both 
alcoholism and certain cancers may have direct genetic linkages.

2. Teacher Resources:   "Genetics from the Beginning "

3. Teaching Tips: 
This is an activity which leads to a lot of natural excitment as students 
discover something about themselves that has remained hidden from 
their own awareness.  Expect a certain amount of conversation to take 
place.   


Note concerning adopted children/children with single parents:   
Students who are adopted are always a concern when genetics related 
activities are attempted,  but that in itself shouldn't keep the class from 
doing this and other comparative lessons.  For the section/lessons 
where students take charts home to compare with their siblings or 
"parents",  they are in this activity simply comparing other people 
within their immediate "sphere of contact"  in order to observe the 
diversity which exists within the human population.  It isn't necessary 
to have them try to find correlations between themselves and their 
family,  biological or otherwise.  Of course,  there may be correlations 
within a family in many cases.  The fact that there may be little or no 
correlation doesn't always mean to much,  however,  in that many 
traits can skip generations because they are carried invisibly by a parent 
from a grandparent.  One example is baldness, which is carried 
invisibly by the mother from her father,  but can show up in her male 
offspring.   In the case of adopted children,  or children who live with a 
single parent in which they have no or little contact with one biological 
parent,  sensitivity is important.  Several strategies may be used in this 
circumstance.  First,  the whole activity can be simply looked at as one 
in which variation among humans are being observed or noted.   If 
students are particularly interested in finding out about their family 
and how it related to them,   it may be best to pick one or two families 
within a class who have two biological parents in residence and a 
number of siblings,  and use them as an example for everybody else.  
This could be done by asking for parential permission in a note home.   
In some cases,  it is also important to realize that adoptive parents often 
try to match a number of visable characteristics as part of the adoption 
selection process.  In that case the student can find out how many of 
these lesser known traits he or she has with the adoptive parent.  More 
interestingly for the adopted child,  if the adoption is an open 
understanding for the child,  this activity gives them a chance to know 
something about their hidden biological history,  about a biological 
parent they may never see.  This is of particular interest also to 
students from single families who never see one of their parents.  
Students  have an inherent curiosity about these things,  and this 
activity gives them a "safe" way to explore their genetic linkages.  Often 
it is very appropriate to mention the ideas above during class early on,  
without identifying students or before they identify themselves.  Often 
the teacher may not be aware of whether there are adopted children in 
class.  Often a student will come up later in private and let the teacher 
know this information,  so it helps to be able to have these ideas out in 
the open.  It may also be appropriate to write a short note to parents 
explaining some of the above information,  asking for comments 
before proceeding.  

4. Procedures: 
Students are shown a variety of genetic characteristics  (phenotypes,  
which are the visable traits of an individual).  Use overhead of Gene 
Wheel to assist students by modeling your own characteristics.

Using the "Gene Wheel Chart" they then color or shade in the traits on 
the chart which pertain to them. Some of the traits may need 
explanation (see background info). 

1. Start with the center,  left-handedness/right-handedness.  Have each 
child decide which handed they are. If they aren't sure or say both 
handed,  ask them which hand they throw a ball with or write with.  
Demonstrate with one you are doing for yourself on an overhead 
transparency.

2. Students shade in one side or the other of the inner circle.  From that 
time on they will be all on that side only.  Go to the next circle out from 
the middle.  Choose the appropriate section on either the left or right 
side to shade in.  You will have to explain or demonstrate traits as they 
are introduced,  possibly before working on the chart.  In particular,  
what is meant by "double jointed"  or "tongue roll" may need 
definition.  Double jointed may be confined to just hands,  or involve 
other limbs at the teachers discretion.  Tongue roll can mean actually 
being able to flip over the tongue,  or it can just be a tongue curl.
3. Continue outward until each person gets to the outer circle.  At the 
end of this part of the activity,  each persons Gene Wheel should look 
like a clock face with a "hand" of trait going out to the edge.  
4. Have the students number around the edge from 1 to 32.  There are 
32 different possible clock faces.
5. If desired have students in groups share their own individual Gene 
Wheels.  Ask if anybody thinks they have a sheet exactly the same as 
anybody else in the class.  Take time to read off several of the numbers 
and see how many students do have the same characteristics.  
6. Introduce the second Gene Chart to the students.  (see notes 
regarding adoptive children under "teaching tips")  This will be the 
one they can take home to compare with their siblings or parents.  
Explain how although the Gene Wheel is visually more fun,  it is 
arbitrary in that it starts with left and right handed in the middle,  etc.  
Ask the students how the charts might look if  something else was in 
the middle,  like ear types.  How would that change their Gene Wheel 
results? 
7. On the Gene Charts there are other traits to introduce as well.  The 
description part is to help them describe more specifically any special 
traits they have.   For example,   they may have a particular type of 
double jointedness,  such as the ability to bend two fingers on their left 
hand into "witches fingers" or they can wiggle their ears.  These can be 
described,  then compared with others in their family.
8. After helping them to fill out this second chart,  have them take it 
home to compare with their siblings and parents or grandparents.  

Other Notes on Procedures:

Students can share their results in a group and create a quick group  
graph.  They should also be given time to share unusual traits,  even 
those not on the list.  Students might enjoy trying to find out 
somebody in class who shares several traits with them.  These student 
groups could share with other groups what they have in common.   
They can make predictions as to which are really the most likely or 
least likely traits to see in their class as a whole.

Have students graph and figure out approximate class figures for 
various traits.  Students will find out all kinds of interesting or unique 
traits among their fellow schoolmates.

Note:  When students  take their own charts home to compare with 
their siblings,  parents,  or relatives.  If this is done around a family 
holiday,  such as Thanksgiving,  relatives may be more available.  Just 
getting results from immediate family is sufficient.  In the case of 
second parents or absent biological parent,  students can still compare.  
It is important to note that physical traits of second parents will not 
have been passed down to the students,  even if they have known 
them all of their life!  Students are sometimes confused or don't 
understand this concept!

5. Wrap-up & Assessment:  
Have students write about how they feel about their "Great Traits".  
Assessment Questions:
- Is there a trait which they would like to have,  a "Favorite"  trait? 
- From whom in your family did you get certain traits?
- What trait to you want to pass on to your children?
Write:  "I am like others because...":  I am unique because..."

6. Extensions:  
Have students graph and figure out  school figures for various traits.  
Students will find out all kinds of interesting or unique traits among 
their fellow schoolmates and will want to have individuals come in to 
demonstrate for all to see!  If exactly 100 students are polled on a 
specific trait,  the concept of percentages might be introduced.

7. Curriculum Connection Explanations: 
Math:  there are numerous graphing and statistics activities which can 
come out of this activity.  Students can gather data from other classes 
and compare with their own.  "Most unique" (least seen)  trait can be 
identified,  as well as other general comparisons.  Even looking to see if 
there are trait correlations,  that is,  does having one particular trait 
lead to others?

Social Sciences:  this tends to be a case of being "normal",  whatever 
that is,  is boring.  Generally,  every student will want to find some trait 
which is somewhat unusual,  but not all students will be able to do so.  
An activity which asks the question:  what trait would you like to have 
which you don't,  could lead to interesting discussions.  Or, "how do 
you feel about your own Greatest Trait?"


Where are you on the Gene Wheel?                Name:	
	Final Number: 

In the chart below start by number all around the wheel from 1 to 32 
(some numbers are already placed for you.  You will start at the middle 
and work outward.




How is this "Wheel"  arbitrary?  Does anybody else in your class have 
the same number as you?  What number would be for the person who 
had ALL of the most likely traits? 


GENETICS  TRAITS  CHART  

Note:  there are various other possibilities, such as Dominant Eye,  
Colorblindness,  Tongue Roll or Curl,  Blood Type,  Widow's Peak,  
Double Jointed (other limbs),  Hitch-hiker's Thumb, Dyslexia,  certain 
diseases,  including certain Cancers.



Less Likely Trait	
More Likely Trait
	
Description 
if needed
	
Parents	
Grandparent
Siblings or other

Left Handed
	
Right Handed

		
	

Right Thumbed
	
Left Thumbed

		
	

Attached Ear Lobes
	
Unattached
(hanging)
Ear Lobes	
		

Short Index Finger
	
Index and 3rd Finger Equal Length
		
	

Long 2nd Toe	
2nd Toe NOT Longer Than 1st
		
	

Double Jointed Hands/Fingers or Thumbs	
No Double Jointedness With Hands	
		



		
		


Like,  But Not Just Alike
---------------------------------------------------------------------------------------------------
--------------

 1. Storylink:   Among populations within single species, there are 
considerable variations, some of which may be easily observed.  
Variation can show the degree of individuality which exists among a 
species,  but characteristics can then be grouped to show similarities 
among individuals as well.  

2. Overview:   In this activity students measure their heights and spans 
to develop a class graph as a way of illustrating variation within a 
species.    Then,  using the information gained from previous lessons 
"Great Traits",  as well as this one,  students choose and chart a family 
characteristic,  using a family tree.

3. Key Concepts: 
1) Although members of a species share many traits,  there are 
variations between individual members with regard to specific traits.
2) The relationship between height and span is close to unity,  a trait of 
the human species.  That is height approximates span.

4. Grade Level: 3 and up

5. Advanced Preparation: 
1) Select wall space throughout the room,  several stations,  where 
meter sticks can be taped to the wall.  If not enough meter sticks are 
available,  a paper strip may be cut and labeled for centimeters.  
Students could also create these strips as a math task.
2) Review metric units (centimeters).  Measurement will be to nearest 
cm,  so a practice activity for that skill might be appropriate.  Hint:  try 
measuring pencils,  or finger length or objects like paper clips and 
sheets of paper.
3)Prepare area of board for recording class results,  or have graph on an 
overhead transparency.
4) Duplicate team data sheets.  Duplicate family tree charts

6. Time: 2 Class Periods for Height/Span.  Several days for optional 
family tree study.

7. Grouping Suggestions:  3-4 Students on a team.
8. Materials (per class):   
	Meter  sticks or strips for each group
	Data Sheets "Comparing Individuals" for each group
	Masking Tape,  and Paper for Class graph
	Overhead Transparency (optional)

9. Thinking Processes:   Observing,  communicating,  comparing,  
organizing.
10. Curriculum Connections: Math

1. Teacher Background (includes vocabulary): 
The offsprings of cats are cats,  of pine trees are pine trees,  and of 
humans are humans.  When members of a species reproduce,  the 
offspring are always similar to other members of that species.  Similar,  
however,  does not mean identical.  Variations do exist within a 
species--not all humans have the same eye color,  hair color,  or skin 
color,  grow to the same size,  or have the same abilities.  When traits 
are compared within large populations,  it is generally found that the 
majority of the members will have close similarities and smaller 
numbers will have variations on either side of this average value.  In 
other words the variation will show a normal distribution or bell-
shaped curve.
The first activity focuses on two separate characteristics,  which are 
somewhat related,  and allows the students to discover and compare 
variations within each characteristic and their relationship.  
Vocabulary:  similar,  variations,  span,  relationship,  species.

2. Teacher Resources: Obtain a copy of Leonardo Da Vinci's  "The 
Proportions of Man" from an encyclopedia.  (A fig leaf might be in 
order,  in certain communities!)  Show this towards the end of the 
activity.  AIMS:  Are You A Square.

3. Teaching Tips: 
It is suggested that students do both measurements (span and height) 
in their groups at the same time.  There is no reason,  however these 
activities couldn't be done entirely separately,  and the results 
compared later.  The graphing of height and span should probably take 
place at separate times so that the class can concentrate on one 
characteristic at a time.  The two characteristics and their relationship 
may  be observed and discussed afterwards.

For the second part of this lesson,  be aware that some of your students 
may not be living with their biological parents.   Please see Teaching 
Tips for Great Traits Activity for a more detailed discussion of this 
issue.  In some cases this can still become an important learning 
experience,  especially if the child has several of their non-biological 
parents' physical features.  Many adoptive parent seek children which 
have physical characteristics in common with themselves.  If this isn't 
the case,  children can still trace traits which are in their immediate 
family.  Another area of concern are single parent families where 
contact with one parent is non-existant.  One option for some 
communities is to choose pets and look for traits in litters.  Another is 
to form groups and only have one person in the group do the family 
tree with the assistance of the other members.  The chosen student of 
the group should be living with both of their biological parents or be in 
close contact with them.   They should also have several siblings.   This 
way not all families will need to be researched,  but all of the students 
will aid in research.  If most of your students are from one ethnic 
group, choose a characteristic other than hair color or eye color.


4. Procedures  (part 1): 
1) Ask students to give some examples of similarities and differences 
between them (e.g.,  similarities might include two eyes,  two ears, one 
nose,  hair on head;  differences could include hair and eye color,  
height,  weight, male and female,  skin color, etc)
2) Ask students to brainstorm  "true statements" which can be made 
concerning similarities and differences among humans.  Lead them to 
conclude that,  although members of a species are similar in most of 
their features,  it is also true that organisms of the same species are 
nearly always different or "show variation" in some of their features.
3) Divide the class in groups and ask them to measure the height of 
each group member,  and the span of that same member,  and 
document it on the data sheet "Comparing Individuals".  Explain that 
they will measure to the nearest centimeter.  Model or demonstrate 
each measurement,  and how to chart it.  Have groups record their own 
group data,  then transfer that to the class results chart.  Probably this 
and the following parts should be done one characteristic at a time,  to 
avoid confusion.
4) Have the class help organize the heights in intervals of 10 
centimeters,  and have them help you with a starting and ending 
range.  Using dots to represent students,  a large graph can be done for 
the whole class.   You may wish to produce a class graph ahead of time,  
and start at 100 cm,  and go up in 10 cm jumps,  going horizontally.  
Then students will place dots on this axis,  and a bar graph will be 
completed.   For the span graph,  this can either be done on the same 
graph with different color dots,  or as a separate graph.  An optional 
extension is to have different dots for males and females,  after asking 
students if they think that might be useful in terms of gathering 
information.  A question might be,  "What might we learn if we had a 
way of separating the heights of males and female? "(by using different 
color dots).   
5) For each student data sheet,  information  in the span to height 
column "which is bigger or are they equal?" should be completed.  The 
students choose between "span",  "height"  or "approximately equal".  
This data may then be graphed by having 3 columns and dots for each 
student.
6) After each characteristic is graphed,  some lead a discussion about 
what the students can tell from the information gathered.  A good 
method is having students find "true statements" about the visible 
data,  and writing these down,  first in their own groups and then 
sharing with the whole class.
7) Have the class determine the highest and lowest figures (optional) 
and guess what a middle value (average) height and span might be.  
Have them guess or predict what they think a reasonable value would 
be for the next grade level.  An extension can then be to determine 
these types of information.


Procedure  (part 2):
1. Ask the students if they are all members of the same species.  Do they 
all have similarities? What are they? Do they all have differences? 
What are they?
2. Choose a characteristic (e.g. eye color, hair color, right or left 
handedness, etc.  Use information gathered from Great Traits lesson) to 
use for the lesson. Determine each student's characteristic and graph 
the results.  
3. Discuss the variation in the graph.  Explain that even though they 
are all the same species, there is variation. Ask if their characteristic is 
the same as any brothers or sisters they might have. Remind them 
their cells carry information which is passed on from parent to child.  
Tell them that there is a kind of code which makes sure they turned 
out to be humans and not turtles, or birds,  and that this information is 
carried by their cells.  Explain that they had inherited  this coding from 
their mothers and fathers, and that their parents individual codes were 
combined to make them,  so that this mix of information from each 
parent gave them their own traits. 

5. Wrap-up & Assessment: 
Part 1:  Show the class the Leonardo Drawing and ask for comments on 
it.  If there are students whose span and height are close to identical,  a 
wrap-up activity might be to outline them on paper,  with their hands 
stretched out,  then draw the square around them.  Then have students 
choose two other measurements which they think might be related,  
and have them draw and measure/label these,  and write/conjecture 
about what they think the relationship is. 
Part 2:  Have students share their family research and trees,  and discuss 
what they have learned about their family traits.

6. Extensions: 
Students may wish to try to recreate Leonardo's proportion drawing 
using someone in their own group.  Notice that the square is height 
versus span in dimensions.  The circle is a little harder to figure.  
Measuring from just above the navel (at the solar plexus) to the feet 
will give an approximate radius.

7. Curriculum Connection Explanations: 
Math:  in the graphing of each characteristic a number of relationships 
may be examined,  depending upon the sophistication of the student 
group.  The idea of Range,  the bell curve concept,  are obvious points 
on each graph.  Averaging may be beyond student grasping,  unless 
calculators are used,  but this could be an enrichment activity.   When 
comparing span to height,  an awareness level of ratio may be 
introduced:  i.e.,  how are the two measurements related,  both to 
individual and as a class.  (see above,  under procedures).  By showing 
Leonardo's drawing,  students will be introduced to how the geometry 
of the human body is of importance

8.  Literature Connections:  Animals Large & Small,  Annette Tison,  et 
al,  Grosset & Dunlap 1989.

Lesson:  Like, But Not Alike..........Are You A Square Or A Rectangle?
Comparing Individuals Chart (Height vs Span)

TEAM MEASUREMENTS

Name
	Height (cm)	Span (cm)
	Span/Height


	Note:  For Span to Height comparisons,  use a calculator and 
round off at two decimal places.  Also,  draw a horizontal rectangle if 
the span is greater than height and a vertical rectangle if the height is 
greater than span.  Draw a square if the two measurements are within 
one centimeter of each other.



Some Ideas to Consider
For Experimentation
	
Hypothesis
	
Evidence/Proof

What can be observed 
re Height/Span about 
Girls versus Boys?
		

What can be said about
the results for either
shorter people or taller
people with respect to
height versus span?
		

What can be observed
by comparisons with
siblings or parents?  Is
there a trend?  How
does age affect the
results?
		


Family  Tree Chart:  Genetics Mini-Unit



Veggie Variation
---------------------------------------------------------------------------------------------------
---------Storylink:  Among populations, even within single species, 
there are considerable variations, some of which may be easily 
observed. Variation can show the degree of individuality which exists 
within a species.

Overview:  The students will do quantitative measurements and 
estimation on several species of vegetables, graph their results, and 
discuss their research.

Key Concepts:  Although there are many traits which species share in 
common,  there are measureable variations between individual 
members.   The information which each parent plant carries may be 
passed on to its offspring.  Certain traits may be more useful than 
others.  In agriculture,  some traits or characteristics may be of special 
use.

Grade Level: 3
Advanced Preparation:
l. Duplicate worksheets.
2. Gather materials.
3. Prepare large class graphs.
4.  Buy  corn, squash, and oranges.  Other fruits or vegetables may be 
used as well  (bananas,  tomatoes)

Time:	2-30 minute 
periods.
Grouping:	Students 
divided among three stations

Materials:	
Per Orange Group Member	Per Squash 
Group Member
2 Oranges,  cut in half	1/2 Acorn 
Squash	
Measuring tape or ruler	Paper cup 
for seeds
juicer ;  worksheet                                   
Worksheet
cups for juice;  measuring cylinder	Scale;  
measuring tape;  paper towels

Per Corn Group Member	
1 cob of corn
Measuring tape
Paper bag for leaves
Worksheet

Process Skills:	Observing, 
communicating, comparing, relating,estimating.
Curriculum Connections:	Math
Vocabulary: Code, traits,  species, characteristic,variation, variance and 
circumference,  inheritance


1.  Teacher Background:  Our personal characteristics (traits) are 
determined by genes (genetic code or DNA) found in chromosomes in 
the nucleus of each cell. Chromosomes are found in pairs. In sexual 
reproduction, one half of each pair is contributed by each of the parents. 
If one gene of a pair has greater influence on a trait than the other gene, 
we call it dominant. If it has less influence, it is recessive. In some 
instances, the offspring may resemble one parent more than another, 
due to having received more dominant genes from that parent.  
Sometimes offspring look very different from their parents or each 
other because genes can be exchanged or "cross over" on chromosomes 
during formation of the egg or sperm. In other cases, offspring may 
resemble grandparents or other family members rather than either 
parent.

2.  Teaching Tips:

Obtain enough vegetables for each group to have a reasonable sample.  
Have several items of one species of vegetable at each table and have 
student do the measurements for that species.  There should be two 
groups for each species for comparison of results.  Optionally,  students 
can rotate to each table so that they study the variations among 
different species.  Optional:  Use rubber gloves for squash seeds, since 
they are "yucky".  Also,  the seeds could be collected,  roasted then 
counted.  To measure the circumference and diamter of the oranges 
requires some measuring skill.  The relationship between the two can 
be explored,  but beyond an introduction this may be a difficult concept.  
The worksheet can be separated into sections so that students aren't 
confused with too much information.  Some teachers may want to do 
one veggie at a time.  This allows for more control,  but more veggies 
are needed.

3.  Procedure:

1. Review the results from "Great Traits"  or "Like,  But Not Just 
Alike",  or   ask the students if they are all members of the same 
species.  Do they all have similarities? What are they? Do they all have 
differences? What are they?

2. Discuss the variation found in the graphs done for those lessons.

3. Explain that even though they are all the same species, there is 
variation. Ask if their characteristic is the same as any brothers or 
sisters they might have. Remind them their cells carry information 
which is passed on from parent to child.  Tell them that there is a code 
which makes sure they turned out to be humans and not turtles, or 
birds,  and that this information is carried by their cells.  Explain that 
they had inherited  this coding from their mothers and fathers, and 
that their parents individual codes were combined to make them,  so 
that this mix of information from each parent gave them their own 
traits. 

4. Discuss with the students that just as there is variation in humans, 
there is variation in all living things.  Tell them they are going to 
examine a variety of vegetables.  While at first glance each individual 
vegetable looks very much like all the other members of its species,  
they will be looking for variation among individuals of each species.  
Explain that each of the seeds from the parent tree carried the same 
basic genetic information but each of the offspring turned out a little 
differently from the other.

5. Assign the students to one of the three groups and explain to them 
that they will make various measurements at each station.   Make sure 
that each center has the required worksheets and equipment.  
Optionally,  have students discuss and generate characterisitics (seeds, 
sections,  thickness, circumference),  which may show variance among 
similar species of vegetables (oranges,  squash,  etc).  After building a 
list,  these can be the characteristics measured.  Note on squash seeds:  
see teaching tips for ideas.

6. For each measurement, calculate the variance (the difference 
between the smallest and largest measurement).  Discuss the results 
emphasizing the variety found in the samples.

Wrap-up and Assessment:  Ask each group of students to report on 
their findings.   Discuss the variety they found within each species.  
Compile a class graph for each vegetable.
- What characteristics does each type of vegetable have?
- How are they the same? 
- How are they different?

Extensions:
1. Repeat the activity using a characteristic other than the original one 
chosen.
2. Ask the students to bring in examples (pictures in books, or draw 
pictures) of variation.
3. Have students examine other species (flowers, beans, other 
vegetables, etc.) for variation  (for example,  a snow peas may vary in 
size,  number of seeds,etc.).
4. Ask a student with a litter of animals at home to report on their (fur) 
coloring and relate it to the parents' coloring.
5. Encourage students to share examples of species variation 
throughout the year.
6.  Play a game of Unique You from AIMS with the entire class.
7. Visit a supermarket for a field trip,  to look for more variations 
among different veggies.  This activity could be started with such a field 
trip.
8. Use the squashes and other veggies to do art prints.

Orange activity adapted from "One of a Kind Oranges", Project AIMS

Veggie Variation Worksheet
----------------------------------------------------

Orange Data Collection
1. Use a centimeter measuring tape or ruler.  Mark the edge of an 
orange which has been cut in half,  then roll it along the tape to 
measure its circumference,  to the closest 1/2 centimeter.
2. Measure the diameter  (across the center) of the orange to the closest 
1/2 cm.
3. Count the number of sections.
4. Squeeze the juice into a cup then pour into a graduated cylinder and 
take measurement.  Compare the two oranges (4 halves)
Results:
Circumference  (distance around)  =  _________ cm;  _________  
cm
Diameter (distance across) =  _________ cm;  __________ cm
Sections  =  _________;  __________
Amount of juice from one orange=  ________________  mL or 
ounces
----------------------------------------------------
Squash Data Collection  (acorn type,  or pumpkin)
1. Measure the diameter  (across the center) of the squash (cut in half)  
to the closest 1/2 cm.
2. Count the number of sections,  bumps or segments.
3. Measure weight of half squash
4. Count the number of seeds.
Results:
Diameter (distance across) =  _________________  cm
Sections  =  _____________
Weight =  _________________  gms or lbs
Seeds  =  ___________________
(roast seeds for snacking!)
----------------------------------------------------
Corn Data Collection
1. Count the number of leaves shucked
2. Measure the length   of the corn ear  to the closest 1/2 cm.
3. Count the number of rows of kernals.
4. Count the number of kernals in three or more rows
5. weight of ear  =  __________________  gms or lbs.
Results:
Leaves shucked =  _________________
Length of ear =  _________________  cm  
Rows of kernals  =  _____________
# of kernal in rows  = 1)  _________    2)  _________   3)  
___________
Weight =  _________________  gms or lbs