Course
Profile Biology, Grade 11, University
Preparation, Public
Unit
5: Genetic Continuity
Time: 26.5 hours
Activity 5.1 | Activity
5.2 | Activity 5.3 | Activity 5.4 | Activity
5.5 | Activity 5.6 | Activity 5.7
In this
unit, students develop an understanding of variability, meiosis, Mendel’s model
of inheritance, and forms of inheritance that extend beyond Mendel’s model. The
students’ ability to identify patterns, predict outcomes and solve problems
involving monohybrid, dihybrid, incomplete dominance, co-dominance and
sex-linked traits is emphasized through the collection and examination of raw
data in place of the traditional word problem approach. Students also examine
some of the technological advances and the contributions of eminent
investigators that led to the modern concept of the gene and inheritance. As a
final task, students participate in a debate about a current genetics issue.
|
Activity |
Time |
Expectations |
Assessment |
Task/Focus |
|
5.1
Introduction to Variability |
75 min |
DL3.02 |
Diagnostic |
Small
group brainstorming and reporting; teacher-led discussion; data gathering and
organizing |
|
5.2
Factors Which Carry Variability |
150 min |
GC1.01,
GC1.02, GC3.01 |
K |
Teacher
directed lesson; students work with models; review of student understanding
of mitosis |
|
5.3
Sources of Variability |
300 min |
GCV.01,
GC1.02, GC1.04, GC2.01, GC2.03, GC3.01, GC3.03, DL1.05, DL3.02 |
K, I, C |
Teacher
led-class discussion; student problem-solving laboratory activity; role play
of process of meiosis |
|
5.4
Mendelian Genetics |
225 min |
GCV.01,
GCV.02, GC1.02, GC1.03, GC2.04 |
K, I, C |
Student
investigation; teacher-led discussion; students design and perform laboratory
investigation, pool class data and propose models to explain |
|
5.5
Inheritance of Traits and Patterns of Variability |
300 min |
GCV.01,
GC1.06, GC1.07, GC2.02 |
K, I, C |
Students
use their data and teacher-supplied data to define terms and use Punnet
Squares to solve problems |
|
5.6
Genetic Disorders |
270 min |
GCV.02,
GC1.05, GC2.05, GC3.02, GC3.03 |
K, I, C |
Teacher
pre-lab; cooperative small group activity; reporting of results for class
recording of information; students perform pedigree analysis and discuss
implications |
|
5.7
End-of-Unit Tasks |
270 min |
GCV.03,
DLV.03, DL3.01 |
K, I, MC, C |
Research
and small group formal debates; fact-based opinion writing assignment using
debate information and research |
·
Germinate
plants required for Activity 5.4.3 in sufficient time so that they are ready
for analysis in Activity 5.4.3.
·
Introduce
tasks and assign topics for Activity 5.7 early in the unit so that students can
gather information throughout the unit.
·
Collect
recombination data from a variety of sources.
·
Book
access to the computer lab as required.
·
Be
aware of current information in the field of genetics, as the content in this
area is changing rapidly.
The
following sites are good general resources, which include a variety of links to
other genetics sites.
Genetics Education Centre – www.kumc.edu/gec/lessons.html
The Gene School –
http://library.advanced.org/28599
Mendel Web – www.netspace.org/MendelWeb/
Time: 75 minutes
The first
activity introduces students to the variability that is present around them. By
brainstorming examples of characteristics that make each of them unique,
students collect evidence of this variability. Students then have the
opportunity to “measure” their degree of variability and compare it to their
classmates. The teacher can clear misconceptions and enhance prior knowledge.
During this time, students should be introduced to the end-of-unit tasks
involving a debate and piece of reflective writing (refer to Activity 5.7).
These tasks allow students the opportunity to describe the connection between
the study of genetics and its influence on society. This connection will form
the basis for one area of the Final Assessment Task (Biotechnology Symposium)
occurring towards the end of the course.
Strand(s): Diversity of Living Things
Learning
Expectations
DL3.02 -
demonstrate an understanding of the connection between biodiversity and species
survival.
·
The
knowledge and skills developed in Unit 1: Diversity of Living Things.
·
Apart
from content from SNC1D Reproduction Strand, no prior genetics knowledge is
required.
·
Teachers
may wish to supply large chart paper and markers for brainstorming sessions.
·
Allow
time for the introduction of Activity 5.7 (debate and the “opinion piece” of
the end-of-unit task), including the formation of groups and the introduction
of the rules of debating.
·
Make
yourself and your class aware of the presence of certain sensitive issues
regarding heredity (e.g., deceased parent, blended families, adopted children,
victims of disease in the family).
5.1.1 Student Activity: In small groups, students brainstorm
answers to the following question: What characteristics or traits do we possess
which make us unique/variable when compared to another person? and Why is
variability beneficial in a group/population? Students use large chart paper
and markers provided to record their ideas. Group answers are presented to the
class.
Teacher
Facilitation: Begin
by asking students Who IS in your class after all (not by name)? Set the stage
for the brainstorming activity by helping students to identify different types
of anatomical and physiological variability that may exist between students for
example, coloration, blood type, chemical sensitivity, etc. Then students have
the option of attempting to categorize the traits. Recall the Diversity unit
previously studied in this course to focus on the importance of variability to
the success of a group/population and the relationship between genetic
variation and diversity. The end-of-unit task (Activity 5.7) should be
introduced at this time so that students can conduct their research throughout
the Unit.
5.1.2 Student Activity: Given a tool (“genetics wheel” or
numbering system) for organizing variability, students quantify their degree of
variability for a particular list of traits. The final number is called the
Variation Number. Students compare their Variation Number with other students
to assess the level of variation. Class data collection and discussion of the
results follows. Students may wish to repeat the exercise with their family
members, or through a school survey of students and teachers, and compare the
degrees of variability within and between groups.
Teacher
Facilitation: Choose
6 -10 physical traits for analysis. Discontinuous traits such as
tongue-rolling, handedness, ear-lobe attachment and thumb cross will present
few problems. However, polygenic traits (eye colour, hair colour) can also be
used and re-investigated in Activity
5.5. Class discussion surrounding results should include: any repeats of
Variation Number (twins?); effect of sample size and population size; link to
diversity. A Genetics Wheel is a common resource available in most Biology
textbooks. If a Genetics Wheel is not available, an alternative suggestion is
to choose an easily measured trait (such as height), measure the trait in
class, and prepare a histogram to illustrate variability.
No formal
assessment is required. A diagnostic assessment of knowledge and skills with
respect to preparedness for Activity 5.2 can be performed. Students can
continue to look for evidence of variation in the world around them (e.g., in
other animals, in plants).
·
Be
aware and sensitive to a student’s personal experience with a particular
genetic disease/disorder.
The Gene School –
http:/library.advanced.org/19037 – an excellent source of experiments,
tutorials, quizzes on all genetics topics
@Genetics
– www.atgenetics.com – a collection of search engines for genetics topics
http://library.thinkquest.org/19037/teach_links.html
-a collection of genetics activities
http://chroma.mbt.washington.edu/outreach/WHO.html
– a game which introduces concepts of traits and diversity.
Time: 150 minutes
In this
activity, students explore the relationship between DNA, genes, alleles and
chromosomes. They review the process of mitosis as a means for producing
genetically identical cells and identify that another mechanism must be present
to allow for the variability identified in Activity 5.1.
Strand(s): Genetic Continuity
Learning
Expectations
GC1.01 -
demonstrate an understanding of the process and importance of mitosis;
GC3.01 -
summarize the main scientific discoveries of the nineteenth and twentieth
centuries that led to the modern concept of the gene;
GC1.02 -
explain how the concepts of DNA, genes, chromosomes, and meiosis account for
the transmission of hereditary characteristics from generation to generation.
·
An
understanding of mitosis from the SNC1D Reproduction Unit.
·
Prepare
diagrams and models in advance to help illustrate the relationship between the
terms.
5.2.1 Student Activity: Students participate in a
teacher-directed lesson about the mechanism for transfer of information,
structural and functional relationship between DNA, genes, alleles and
chromosomes, DNA replication, and cytoplasmic inheritance. Students build
models of chromosomes and use the models to simulate the replication process.
Teacher Facilitation: Use a
variety of teaching aids including diagrams and models to explain the role of
DNA in the transfer of information. The relationship between DNA, genes,
alleles, and chromosomes should be emphasized. Identify misconceptions about
the structure of genes and use this as a focus for the lesson. Introduce the
contributions of scientists such as Watson, Crick and Rosalind Franklin to our
understanding of the structure of DNA.
5.2.2 Student Activity: Students use the models previously built to
demonstrate the need for the duplication of chromosomes to produce new cells
with identical genetic composition. They review the concept of mitosis as a
mechanism for the creation of new cells. Students identify that the cells
produced by mitosis are genetically identical to the original cell and identify
situations where the production of such cells is required. Using the results of
Activity 5.1, students discuss the need for another mechanism to account for
the variation seen within the class.
Teacher Facilitation: Use this opportunity for a diagnostic
assessment of students’ understanding of mitosis which was covered in SNC1D.
The emphasis of this section should be on the use of mitosis as a process to
create new cells, not a detailed study of the stages of mitosis.
·
Assess
the knowledge and understanding of the relationships between genes, chromosomes
and DNA using a quiz.
Genetics
Science Learning Centre – http://gslc.genetics.utah.edu/basic/index.html
– a tutorial about genes, DNA and chromosomes.
Time: 300 minutes
The
purpose of this activity is to identify the factors that contribute to
variability in an individual and in a population/group. The introduction in
Activity 5.1 to types of variation in individuals can be recalled as a lead
into its inherent causes. Lab activities will be conducted to illustrate
recombination. The significant events of meiosis (reduction in chromosome
number, recombination) are highlighted. A role-playing exercise will be
performed to reinforce the principles of meiosis.
Strand(s):
Genetic Continuity and
Diversity of Living Things
Learning
Expectations
GC1.02 -
explain how the concepts of DNA, genes, chromosomes, and meiosis account for
the transmission of hereditary characteristics from generation to generation;
GC1.04 -
explain the process of meiosis in terms of the replication and movement of
chromosomes;
GC2.01 -
explain the process of meiosis, with reference to a computer simulation or to
their own investigations with a microscope;
GC2.03 -
organize data that illustrate the number of chromosomes in haploid cells and
diploid cells, and the number of pairs of chromosomes in diploid cells, that
occur in various organisms before, during, and as a result of meiosis;
GC3.01 -
summarize the main scientific discoveries of the nineteenth and twentieth
centuries that led to the modern concept of the gene;
GC3.03 -
identify and describe examples of Canadian contributions to knowledge about
genetic processes and to technologies and techniques related to genetic
processes;
GCV.01 -
demonstrate an understanding of the necessity of meiosis and describe the
importance of genes in transmitting hereditary characteristics according to
Mendel’s model of inheritance;
DL1.05 -
explain the importance of sexual reproduction to variability within a
population;
DL3.02 -
demonstrate an understanding of the connection between biodiversity and species
survival.
·
Knowledge
and skills as studied in the Reproduction Unit of SNC1D.
·
Models
and/or posters of meiosis may be useful to visual learners.
·
For
the recombination lab (Activity 5.3.3), read and collect all required
materials.
·
A
large clear space in the classroom or an alternate area is required for the
role-playing exercise.
5.3.1 Student Activity: Students participate in a class
discussion to identify the processes which contribute to variation. This
discussion provides the knowledge to support the skills of problem solving in
the activities to follow.
Teacher
Facilitation: Lead the class discussion so that students create a list of the
processes/events which contribute to variability. These include: genetic
recombination (Activity 5.3.3); random fertilization between gametes (SNC1D);
gamete production itself (Activity 5.3.2); and mutation. Identify the fact that
gender is actually a simple form of variability through a discussion of gender
determination. Introduction of the terms genotype and phenotype will illustrate
the need for a method to classify the variation. For Canadian contributions to
the study of genetics, the identification of the Barr Body by
Dr. Murray Barr for use in nuclear sexing can be included. Emphasize the
importance of all types of variation to biodiversity and species survival.
5.3.2 Student Activity: Students participate in a class
discussion on the process of meiosis and its role in sexual reproduction in
enough detail to describe how each of the following occurs: chromosome number
is reduced by half; crossing-over occurs; and, most importantly, how these
events contribute to genetic variation in offspring. Students compare the
number of chromosomes and chromosome pairs in haploid and diploid cells before,
during, and as a result of meiosis by organizing data from a variety of
organisms.
Teacher Facilitation: Lead a
class discussion which emphasizes the significant outcomes/events of meiosis
without concentrating on the phase names and details of less significant events
in each phase. The phases, after all, are but snapshots of a dynamic process
and should be treated as such. Add a further contributor to variation to the
list compiled in Activity 5.3.1. That is, the effects of the random independent
assortment of homologues on the equatorial plate. Introduce the terms
homologous chromosomes and recall the terms gene and allele from Activity
5.2.1. See Resources for computer simulation. Alternatively, students could use
prepared slides of the stages of meiosis to reinforce their understanding of
the significant outcomes/events of meiosis. Provide data on haploid and diploid
cells from a variety of organisms before, during and after meiosis for students
to organize.
5.3.3 Student Activity: In pairs, students perform a
problem-solving lab activity involving the recombination of traits by
“building” offspring from a given set of parents. Parental alleles are provided
along with a key of phenotypes and corresponding genotypes. Potential offspring
are produced and the phenotype of each trait is constructed. Class results are
compiled so that the effect of recombination can be illustrated.
Teacher Facilitation: Provide the
student groups with a key of phenotypes and corresponding genotypes. Everyday
objects can be used to allow students to “build” the offspring (e.g., Bb - legs
made of 2 marshmallows, TT - antennae made of 2 toothpicks, gg - 3 body
marshmallow segments, Gg - 2 body marshmallow segments). The point of this
activity is to illustrate that hundreds of possible combinations and
permutations will result for as few as 8-10 traits. See Resources listed below
for detailed instructions.
5.3.4 Student Activity: Students role-play the events of
meiosis (as in spematogenesis with no polar body production) by arranging into
teams of four. Each student represents a chromosome (thus each group is a
tetrad or replicated homologous pair) and coloured bands on the arms and legs
represent alleles. Students “perform” meiosis by walking through the process.
Recombination and reduction in chromosome number should result.
Teacher
Facilitation: Provide the students with coloured fabric or bands to indicate the
alleles of several traits on several different chromosome pairs (discuss the
merit of using a limited number of chromosomes and traits). During
crossing-over, the bands are exchanged and new combinations result. Upon the
end of meiosis, students will form four gamete “cells” one in each corner of
the room and the uniqueness of each gamete will be evident. Random independent
assortment of homologues can be demonstrated more visually here than through a
diagram. (Briefly describe the fate of polar bodies in oogenesis).
·
Traditional
knowledge-based quiz of the sources of variation and the significant events of
meiosis will be conducted.
·
Successful
construction of recombined offspring in Activity 5.3.3 will be assessed through
the use of a checklist and/or self-and peer assessment.
·
A
performance assessment of the role-playing is optional.
·
Include
students with mobility challenges by assigning roles such as the “variability
referees” (responsible for “randomly” announcing the times and locations of
recombination in the role-playing activity), etc.
·
For
enrichment, students can design their own legend of traits for the
recombination lab.
·
For
enrichment, consider the relationship between the distance between two genes on
a chromosome and linkage of corresponding phenotypes.
The
Gene School – http://library.advanced.org/28599/ – A large overview of the
genetics field.
http://esd.iu5.org/LessonPlans/reebop/reebopmain.htm
– provides instructions for the recombination lab (Activity 5.3.3)
www.accessexcellence.org/AE/AEC/AEF/1996/meyer_chromsome.html
– provides instructions for the role-play of meiosis
Meiosis
Tutorial and animation –
http://www.biology.arizona.edu/cell_bio/tutorials/meiosis/page3.html
Great
Canadian Scientists: http://www.science.ca/reference.html – brief biographies
of over 100 Canadian scientists and inventors
Time: 225 minutes
Beginning
with an activity to illustrate the laws of probability, students examine
Mendel’s laws of heredity. They examine Mendel’s pea plant experiments and
explore the role of mathematical analysis in his work. Students design and
perform a lab in which they collect and analyse data resulting from the cross
between two individuals. The focus of this activity is analysis of ratios
collected from lab data.
Strand(s): Genetic Continuity
Learning
Expectations
GC1.02 -
explain how the concepts of DNA, genes, chromosomes, and meiosis account for
the transmission of hereditary characteristics from generation to generation;
GC1.03 -
describe and explain the process of discovery that led Mendel to formulate his
laws of heredity;
GC2.04 -
compile qualitative and quantitative data from a laboratory investigation on
monohybrid and dihybrid crosses, and present the results, either by hand or
computer;
GCV.01 -
demonstrate an understanding of the necessity of meiosis and describe the
importance of genes in transmitting hereditary characteristics according to
Mendel’s model of inheritance;
GCV.02 -
perform laboratory studies of meiosis and analyse the results of genetic
research related to the laws of heredity.
·
Laws
of probability from studies in Mathematics (The Ontario Curriculum, Grade 8)
·
Design
and execution of laboratory activities.
·
Use
Wisconsin Fast Growing Plants or radish seedlings.
·
Plants
must be germinated prior to this activity.
·
Consult
with students and others to determine what preliminary work or bookings will
need to be done if graphing calculators or computers are to be used in Activity
5.4.3.
5.4.1 Student Activity: Students perform a coin-toss
exercise to illustrate the laws of probability and in turn apply these to
Mendel’s laws of heredity.
Teacher Facilitation: Divide
students into pairs and assigns each pair to toss two coins 10 times, record
the data and identify patterns. Two pairs pool their data and identify
patterns. The entire class pools its data and identifies patterns. Lead a
discussion about the laws of probability, the importance of sample size, and
use these concepts to introduce Mendel’s laws of heredity and his use of
probability and sample size in his research.
5.4.2 Student Activity: Students participate in a
teacher-led discussion about Mendel’s pea plant experiments and his use of
mathematical analysis.
Teacher Facilitation: Provide the
background about Mendel’s experiments and lead a discussion about his use of
mathematical analysis. His choice of discontinuous traits and his use of a
large sample size should be emphasised as well as the intuitive brilliance of
his hypothesis.
5.4.3 Student Activity: Students design and perform a lab to
germinate and grow Wisconsin fast-growing plants or radish seedlings. The
purpose of the lab is to analyse genotypic ratios in F1 generation seedlings
resulting from seeds produced by a known cross between two heterozygous
individuals (for example two green radish plants which produce offspring with
different appearances such as green and albino radish seedlings). The emphasis
is on the collection of data and a search for a model to explain the data.
Students could use graphing calculators to identify trends in the data and
develop models.
Teacher Facilitation: Assist
students in the design and execution of the lab as required. It should be noted
that the focus of this activity is on the ratios produced, not on the methods
for predicting the outcomes (Punnett Squares). Class pooling of data is
recommended to reinforce the importance of a large sample size in determining
the ratios. Be cautious that misconceptions are not compounded by this data.
Alternatively, a computer simulation of Mendel’s experiment can be completed
(see Resources). If graphing calculators are to be used, review procedures for
finding “best fit” curves and lines.
·
Assess
knowledge of Mendel’s contributions and laws of heredity on the unit test. Use
a checklist or rubric to assess the lab design and report.
·
Some
students may require additional support in the collection and analysis of data.
Mendel Web – www.netspace.org/MendelWeb/ -
background about Mendel and his experiments. http://library.advanced.org/28599/
www.biology.arizona.edu:80/ – genetics problem
sets and tutorials.
Biology
Labs Online: subscription information. A set of 12 virtual labs on genetics
(requires paid subscription)
http://www.biologylab.awlonline.com/ordering.html#international
Time: 300 minutes
Students
use the experiment performed in Activity 5.4.3 as the context for defining
genetics terminology. They examine data resulting from a variety of crosses,
and use the Punnett Square as a tool in solving various types of crosses which
they collect in a set of solved problems. The intention of this activity is to
begin with data resulting from a particular cross and then develop a Punnett
Square to aid in predictions rather than a traditional word-problem based
activity. Once this concept is established, word problems may be used for
reinforcement.
Strand(s): Genetic Continuity
Learning
Expectations
GC1.06 -
explain, using Mendelian genetics, the concepts of dominance, co-dominance,
incomplete dominance, recessiveness and sex-linkage;
GC1.07 -
predict the outcome of various genetic crosses;
GC2.02 -
solve basic genetic problems involving monohybrid crosses, incomplete
dominance, co-dominance, dihybrid crosses, and sex-linked genes using the
Punnett method;
GCV.01 -
demonstrate an understanding of the necessity of meiosis and describe the
importance of genes in transmitting hereditary characteristics according to
Mendel’s model of inheritance.
·
Knowledge
of ratios from studies in Mathematics.
·
Collect
data from the results of real or simulated crosses prior to this activity.
·
Students
should examine the data and ratios prior to the use of Punnett Squares.
·
This
section will require sufficient time for students to analyse data and solve all
of the types of problems required. The students will be creating a set of
solved problems from this activity only. Student participation in the
preparation of the rubric used to assess this problem set should be done prior
to the start of the activity so that students have a clear understanding of how
they will be assessed.
5.5.1 Student Activity: Using the results of Activity 5.4.3 as a context, students define the
meaning of homozygous, heterozygous, and recall the meaning of gametes, germ
line cells, somatic cells, genotype, phenotype, allele and gene.
Teacher
Facilitation: Assist the students in linking the meaning of
the terms to Activity 5.4.3 and to previous activities.
5.5.2 Student Activity: Students examine the data produced
in Activity 5.4.3, and data provided by the teacher which is the result of
other crosses. They identify patterns in the data (similar ratios). Students
use the Punnett Square as a model to explain the possibilities for inheritance
and solve problems to identify patterns, predict outcomes and solve problems
given monohybrid, dihybrid and test crosses. Students select problems to
include in their problem set.
Teacher Facilitation: Introduce the Punnett Square as a useful tool
for making predictions only after the students have examined some real data and
noted the common ratios. It is suggested that the first Punnett Square be used
to make a prediction about the cross done in Activity 5.4.3. The shift is to
use alternatives to traditional word problems such as the Virtual Fly
software and computer simulations (see Resources). The Punnett Square must be
presented as a useful tool in problem solving rather than the point of the
problem. Where possible, students should pose their own questions and use
Punnett Squares to make and test predictions. Students should also be made
aware in this activity that the term “dominance” applies to traits that are
expressed if present, not necessarily traits that are “better”.
5.5.3 Student Activity: After a teacher-led discussion,
students identify patterns, predict outcomes and solve problems involving
codominance, incomplete dominance, sex-linkage and polygenic traits. Students
select problems to include in their problem set.
Teacher Facilitation: Present
data from non-Mendelian crosses (examples: blood typing, snapdragons,
colour-blindness, hair, eye or skin colour) and encourage students to develop a
model to explain it. Data for these types of problems is available in many
Grade 11 Biology textbooks. Introduce the concepts of codominance, incomplete
dominance, sex-linkage and polygenic traits in relation to the examples
presented. Students use the skills developed in Activity 5.5.2 to solve
problems involving these types of traits.
·
Assessment
of problem-solving skills through a set of problem solutions. This is an
opportunity for a rubric which could be developed with the input of the students.
·
Assessment
of the ability to identify patterns and predict outcomes of various crosses
using the proper terminology will be done on the Unit test.
·
Some
students may require additional support in developing their problem set.
·
For
enrichment, students could consider post-Mendelian phenomena such as epistasis
(interaction of non-allelic genes) and pleiotropy (producing an effect in more
than one trait) as additional background for the debate in Activity 5.7.
http://www.athro.com/evo/gen/genefr2.html
– interactive Punnett Squares for dihybrid crosses of polygenic traits.
http://esg-www.mit.edu:8001/esgbio/mg/mgdir.html
– genetics problems requiring the use of the Punnett square as a tool.
Time: 270 minutes
The focus
of this activity is to establish that the inheritance of a particular genotype
may result in an altered phenotype due to the production of an abnormal
protein. In inborn errors of metabolism, often the protein is an enzyme or
other factor essential to a metabolic reaction. By recalling the inheritance
patterns of certain phenotypes from Activity 5.5.3, a greater understanding of
the origin and impact of particular genetic diseases and disorders results. By
revisiting prior expectations, student knowledge of DNA structure can be
applied to the investigation of the gene location (locus) for many
diseases/disorders.
Strand(s): Genetic continuity
Learning
Expectations
GC1.05 -
describe genetic disorders in terms of the chromosomes affected, physical
effects, and treatment.
GC2.05 -
research genetic technologies using sources from print and electronic media,
and synthesize the information gained.
GC3.02 -
describe and analyse examples of genetic technologies that were developed on
the basis of scientific understanding.
GC3.03 -
identify and describe examples of Canadian contributions to knowledge about
genetic processes.
GCV.02 -
perform laboratory studies of meiosis and analyse the results of genetic
research related to the laws of heredity.
·
Knowledge
that cells operate as systems from Unit 2: Cellular Basis of Life.
·
Knowledge
of the function of the ribosome and its dependence upon the nucleus for
accurately transcribed mRNA.
·
Collect
karyotypes, photographs, case studies, text sources, articles and/or electronic
media (list of websites) which students will use in their Jig-Saw Activity to
enhance their understanding of particular genetic diseases or disorders.
·
Reserve
time in the Library/Resource Centre or computer lab for research if the teacher
does not provide materials.
·
For
the pedigree analysis, provide print resources or use electronic sources (most
diseases will have a foundation or association website).
·
Teachers
are reminded of the possibility of sensitive issues arising during this
activity, such as personal experience with a disease/disorder, blended
families, adoption, etc.
5.6.1 Student Activity: Following a brief teacher-led pre-lab discussion to introduce the phrase
“inborn errors of metabolism” and to recall the effects of mutation on
variability, students participate in a Jig-Saw Activity to investigate the inheritance
and phenotype of particular genetic diseases or disorders and the use of
genetic technologies in their diagnoses. Each individual is assigned a
particular inborn error of metabolism with peer teaching and sharing to follow.
Each student compiles notes on all of the diseases as a result of the peer
teaching and sharing in preparation for a class test on all the genetic
diseases covered.
Teacher Facilitation: Establish
an understanding that these genetic diseases are a result of faulty protein
production at the ribosome, either through a mutation in the DNA or through an
error in protein synthesis. The key concept to establish is that a missing or
faulty protein causes the manifestation of a malfunctioning (i.e., less
adaptive) phenotype. Revisit mutation as a source of variability and its
influence on inheritance. After this discussion, students participate in the
jigsaw activity to investigate a particular genetic disease or disorder
(including Canadian contributions) with the intention that a sharing and
peer-teaching exercise will follow. Areas to investigate include: inheritance
pattern; phenotype; statistical incidence; gene locus (if possible); faulty
protein and its action (if possible); treatment; genetic testing/screening
availability; description of genetic technology required for diagnosis or
identification. Diseases/disorders to investigate include: cystic fibrosis,
muscular dystrophy; Huntington’s chorea; sickle-cell anemia; ALS;
phenylketonuria; hemophilia; Tay-Sachs disease; Thalassemia. The teacher could
provide all resources necessary in the classroom to allow for an efficient
exercise (see Planning Notes). Alternatively, Library/Resource Centre research
may be necessary.
5.6.2 Student Activity: Students investigate the inheritance
of disease using pedigree analysis. The teacher will make print or web site
resources available. The implications of ownership of this genetic information
knowledge and its use in genetic counselling are introduced. The application of
the use of pedigree analysis in dog breeding and in the building of personal
“family trees” is noted.
Teacher Facilitation: Provide
the resources for analysis either in print or in the use of web-sites (see
Resources). Students analyse the pedigrees of actual and/or hypothetical families
(e.g., hemophilia in some Royal families) to follow inheritance patterns
through gender, carriers and phenotype. The societal implications of
“ownership” of personal genetic information and its availability to employers,
insurers, schools and/or partners can be introduced as preparation for the
final end-of-unit tasks.
·
Assessment
of the Jig-Saw Activity through the use of a rubric designed specifically for
this activity by the students and the teacher.
·
Knowledge-based
quiz is used to evaluate the inheritance and phenotypes of the diseases.
·
Enrichment
opportunities arise when studying some diseases such as Huntington’s disease
(Mature-onset of this disease after childbearing age presents the selfish gene
concept.)
·
Some
students may need additional support during the jigsaw activity.
Biology
Labs On Line http://biologylab.awlonline.com – this site contains a variety of
interactive labs, including one on pedigree analysis, but requires a
subscription for access.
Time: 270 minutes
The
end-of-unit tasks for this unit conclude with a fact-based opinion piece of
writing. Based on the knowledge and skills obtained throughout the unit,
students debate an issue as part of a team and then write an individual
reflective piece supported by concepts and facts from the unit.
Strand(s): Genetic Continuity and Diversity of Living Things
Learning
Expectations
GCV.03 -
outline the scientific findings and some of the technological advances that led
to the modern concept of the gene and to genetic technology, and demonstrate an
awareness of some of the social and political issues raised by genetic research
and reproductive technology;
DLV.03 -
relate the role of common characteristics and diversity within the kingdoms of
life (including Eubacteria and Archeabacteria) to the importance of maintaining
biodiversity within natural ecosystems, and explain the use of micro-organisms
in biotechnology;
DL3.01 -
explain the relevance of current studies of viruses and bacteria to the field
of biotechnology.
·
Knowledge
and skills from this unit.
·
Introduction
to these tasks took place in Activity 5.1
·
Divide
students into groups prior to the activity. Be sure that there is a “pro” and
“con” team for each debate question chosen.
·
Rules
for debating should be established prior to the activity. Refer to Appendix 1
below for a suggested debate model and an assessment rubric. Timing may be
adjusted as appropriate to the topics and class.
5.7.1 Student Activity: In small groups, students choose a
position (pro or con), conduct further research, organize their team’s position
and participate in a debate on a particular issue concerning genetic research
and society. Debates on three or four different questions allow all students to
experience the process of debate on one topic and to record information about
other topics.
Teacher
Facilitation: Assist
the students in brainstorming and selecting appropriate resolutions for debate.
It may be necessary for the teacher to provide additional genetic background to
groups working on certain topics. For example, the influence of epistatically
and pleiotropically interacting genes has implications for some of these
topics. Final resolutions to debate may include:
Be
it resolved that:
·
An
individual’s genome should be made available to third parties.
·
Deleterious
genes/alleles should be removed from the gene pool.
·
An
individual should be informed if he/she is carrying a deleterious gene/allele.
·
The
information collected from the Human Genome Project should be public domain.
·
The
government should develop laws to control future genetic research and genetic
technologies.
·
A
couple should be “allowed” to test an embryo for genetic diseases or other
traits (such as gender or intelligence).
If
there are time constraints a second option is to choose only one question with
two large debate teams. The debate teams could be dynamic groups, wherein
students who change their stand on an issue are free to move to the “other
side” of the issue.
5.7.2 Student Activity: As a result of participating in and
witnessing the above debate(s), each student writes a reflective “opinion”
piece on one of the questions debated, supporting arguments with concepts and
facts from the unit and debates.
Teacher Facilitation: Encourage
the students to choose an issue that appeals to them.
·
A
performance assessment highlighting the Communication and Making Connections
Achievement Chart categories can be conducted on the student’s debate
contribution.
·
Learning
skills can also be self and peer-assessed using a checklist.
·
The
reflective piece can be assessed using a checklist or rubric designed by the
teacher with input from the students.
·
A
unit test to evaluate the knowledge and skills of the unit is to be included.
·
ESL
students may require additional time and assistance with the reflective writing
piece.
·
This
activity represents an extension opportunity for some students to expand their
breadth and depth of knowledge through further research.
In this
activity, you will be debating one of the following topics in class. You will
work in groups of three people to prepare one side (Pro or Con) of one of the
resolutions below. You should prepare for the debate by doing research and by
preparing notes for the various speakers. During the debate you will also need
to take notes to prepare challenging or rebutting arguments for the other side.
Your teacher will review the assessment rubric with you.
The debate will involve the following stages:
(a) Introduction
(Pro/Con): first debater defines key terms, the point of view of his/her group
and his/her fellow debaters (2 minutes).
(b) Speaker(s)
(Pro/Con): second debater from each side introduces the main arguments and
facts/examples in support of the group’s point of view (3-4 minutes).
(c) Rebuttal
(Pro/Con): both sides state counter-arguments to the opposing and/or weaknesses
in the opposing side’s arguments or use of facts (any member of the team may
speak) (2 minutes).
(d) Conclusion:
third debater summarizes the key points made by the team and answers questions
(1 minute – more time for questions).
Here are
sample resolutions.
Be it
resolved that:
·
An
individual’s genome should be made available to third parties.
·
Deleterious
genes/alleles should be removed from the gene pool.
·
An
individual should be informed if he/she is carrying a deleterious gene/allele.
·
The
information collected from the Human Genome Project should be public domain.
·
The
government should develop laws to control future genetic research and genetic
technologies.
·
A
couple should be “allowed” to test an embryo for genetic disease.
Debate
Planning Sheet – Answer these questions on a sheet of notepaper.
Name: _____________________ Working with: ___________________________________
Debate
Topic: ____________________________________________________________________
1. What are you trying to prove in your side of
the debate?
2. List three to five arguments and/or facts
that you can use to support your side of the debate.
3. List one to two arguments you are certain
that the opposing side will use to support its side.
4. Explain at least one way in which you could
challenge the arguments of the opposition.
5. Explain how you will divide the
responsibilities for speaking in the debate:
(a) introduction
(b) main arguments
(c) conclusion
(d) rebuttals (person mainly
responsible)
6. What areas will you need to research for your
debate to provide arguments and examples?
7. In what ways can you prepare and practise to
make your debating more interesting and persuasive?
|
Categories/ |
Level 1 |
Level 2 |
Level 3 |
Level 4 |
|
Knowledge Communication Clear
articulation of position |
-
position is not clearly stated |
-
position is recognized, but only clarified through prompting |
- a
clear position is stated |
- a
clear position is stated and fully articulated |
|
Knowledge Making
Connections Communication Provides
support for position |
-
limited support for initial position |
-
support for initial position is present but lacks clarity of presentation |
-
support for initial position is clearly presented and reasoned based on
evidence |
-
supporting arguments for position are both reasoned and persuasively presented |
|
Knowledge Making
Connections Communication Considers
other positions |
-
limited sensitivity to other positions |
- other
positions acknowledged but not considered |
- other
positions acknowledged and considered |
- other
positions considered and effectively incorporated or countered |
|
Knowledge Making
Connections Communication Effectively
critiques positions |
-
limited sensitivity to opponents and their positions |
-
opposing views acknowledged and moderately critiqued or dealt with |
-
opposing views acknowledged and effectively critiqued |
-
opposing views effectively critiqued and opponents treated with sensitivity |
Note: A student whose expectations are below level 1
(50-59%) has not met the expectations for the assignment or activity.
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