Theme: Genetics
Unit Rationale: In science today, there is an increasing focus on genetics. A basic
understanding of genetics and heredity is important to all students as they move on to
high school biology where this subject will be taught in more depth. The use of a basic
Punnett Square is also covered on the standardized tests at the middle and high school
levels. Discussion of careers and ethical issues in genetics teach students that these
concepts do not exist in a vacuum; they are useful in the career world and are being hotly
debated on a national and international level. Knowing this will help students buy into
the concepts they are being taught, now and in their educational future.
Unit goal: This unit will introduce students to genetics and heredity, some basic
applications of these concepts, several careers that use genetics, and the ethical issues that
surround their use. By the end of the unit, students will be able to complete an
assessment test involving each of the six following lessons with at least eighty-five
percent accuracy.
1. “All about genes”
Generalization: Scientists these days are learning more and more about the
structure and content of our genes, which play at least some role in how we look
and act.
Content samples:
Genes, defined
Chromosomes, defined
Genetic disorders
What scientists know and are trying to learn
Key Question: What are our genes and chromosomes, and why are scientists so
interested in learning more about them?
2. Heredity—dominant and recessive genes
Generalization: Genes are inherited from our parents; some are sex-linked and
others are not.
Content samples:
Sex cells
Alleles
Dominant/Recessive traits
Sex-linked traits
Key Question: Explain two ways in which traits are passed down from parents to
offspring.
3. Punnett Squares
Generalization: Punnett Squares can be used to determine the probability of
offspring having a particular trait, as well as which parent carries a particular trait.
Content samples:
How to use a Punnett Square
Determining probability of offspring having a trait
Determining which parent carries a trait
Key question: How do you use a Punnett Square to determine the probability of
offspring having a trait and to determine which parent carries a particular trait?
4. Careers
Generalization: A working knowledge of the concepts taught in this unit is the
first step toward many careers in the field of genetics.
Content samples:
Geneticist
Genetic Counselor
Genetic Engineer
Key question: What careers are available in genetics?
5. Practical Applications
Generalization: A genetic counselor can advise people on what genetic disorders
their children might have using a family tree chart and Punnett Squares.
Content samples:
Using a family tree
Using a Punnett Square
Introduction to ethics: “Is this right?”
Key question: How does a genetic counselor use a family tree and Punnett Square
to determine the probability of children having a certain genetic disorder?
6. Ethical Issues
Generalization: Scientists, the government and ordinary people are evaluating
various ethical issues regarding the uses of genetics that we have just studied.
Content samples:
Article on Dolly the Sheep
Article on human cloning
Article on genetically modified food, plants
Class discussion on the ethics of eliminating genetic “disorders”
Key question: What ethical issues exist regarding the use of genetics and where
do you stand on these issues?
Instructional Objectives
1. All students will understand the concepts of genes and chromosomes well
enough to write them down or say them out loud when asked, 95 percent
of the time. (affective)
Addresses: Lesson “All About Genes”
Generalization: Scientists these days are learning more and more about
the structure and content of our genes, which play at least some role in
how we look and act.
Content samples:
Genes, defined
Chromosomes, defined
Genetic disorders
What scientists know and are trying to learn
2. All students will name and explain two ways in which genes are passed
from parents to offspring, in writing on the final exam, with 85 percent
accuracy. (cognitive)
Addresses: Lesson “Heredity—Dominant and Recessive Genes”
Generalization: Genes are inherited from our parents; some are sex-linked
and others are not.
Content samples:
Sex cells
Alleles
Dominant/Recessive traits
Sex-linked traits
3. All students will complete a simple Punnett Square with 75 percent
accuracy in an in-class group activity and 100 percent accuracy in an
individual project with teacher assistance. (psychomotor)
Addresses: Lesson “Punnett Squares”
Generalization: Punnett Squares can be used to determine the probability
of offspring having a particular trait, as well as which parent carries a
particular trait.
Content samples:
How to use a Punnett Square
Determining probability of offspring having a trait
Determining which parent carries a trait
4. All students will be able to identify several careers that use genetics with
75 percent accuracy on a multiple-choice test at the end of the unit.
(Cognitive)
Addresses: Lesson “Careers”
Generalization: A working knowledge of the concepts taught in this unit
is the first step toward many careers in the field of genetics.
Content samples:
Geneticist
Genetic Counselor
Genetic Engineer
5. All students will use both family trees and Punnett Squares to solve
genetic problems with 60 percent accuracy in an in-class activity.
(psychomotor)
Addresses: Lesson “Practical Applications”
Generalization: A genetic counselor can advise people on what genetic
disorders their children might have using a family tree chart and Punnett
Squares.
Content samples:
Using a family tree
Using a Punnett Square
6. All students will understand and develop opinions on ethical issues in
genetics and will be able to speak comfortably about their opinions to the
class. (affective)
Addresses: Lesson “Ethical Issues”
Generalization: Scientists, the government and ordinary people are
evaluating various ethical issues regarding the uses of genetics that we
have just studied.
Content samples:
Article on Dolly the Sheep
Article on human cloning
Article on genetically modified food, plants
Class discussion on the ethics of eliminating genetic “disorders”