SEPUP Genetics Unit
Activity 7: Breeding Better Rice
Key Concepts
1. In all organisms, the instructions for specifying the characteristics of the organism
are carried in genes. Genes are units of hereditary information that are passed
from parents to offspring.
2. Cells contain two copies of each gene. These copies are called alleles.
3. Selective breeding is a form of technology used to develop desirable crop plants.
4. Students use mathematics and models to analyze data.
Key Vocabulary
Allele Dominant Genes Heredity Recessive Trait Genotype Phenotype
Homozygous Heterozygous Punnett Square
Selective Breeding
Analysis
1. What is the ration of the different phenotypes expressed by the second-generation
offspring?
2. What fraction of the offspring have the desired phenotype?
3. What fraction of the offspring has the desired phenotype and will breed true for
this phenotype?
4. Imagine that you will be doing crosses for the three different genes. How will this
affect your breeding effort? (Hint: What will it do to the percentage of plants that
will breed true for the desired phenotype? How will it affect the number of
crosses you will have to do to get exactly what you want?)
5. Prepare a Punnett square to show all of the possible second-generation genotypes
that could have resulted from crossbreeding two AaFf parent plants.
6. Compare the ration of genotypes produced by your team with the ratio produced
by the class and with the ratio predicted by the Punnett square. Describe and
explain any similarities and differences.
7. Imagine that you will be crossing two plants in an attempt to obtain offspring with
10 desirable traits. What effect will this have on your breeding efforts?
SEPUP Genetics Unit
Activity 8: Breeding Crops with Desirable Traits
Key Concepts
1. In all organisms, the instructions for specifying the characteristics of the organism
are carried in genes. Genes are units of hereditary information that are passed
from parents to offspring.
2. Selective breeding and genetic engineering are two different forms of technology
used to develop desirable crop plants.
3. Selective breeding and genetic engineering each have advantages and
disadvantages.
4. Students use mathematics and models to analyze data.
Key Vocabulary
Selective Breeding genetic modification traits transgenic
Biodiversity
Trade-off
Analysis
Read the article and answer the following for homework:
1. How does selective breeding work?
2. Why did it take so long to breed a blight-resistant, high yield rice plant?
3. What are the main advantages of using biotechnology, instead of selective
breeding, to produce improved crop plants?
4. What are the concerns about using biotechnology to produce improved crops?
5. What more would you want to know before making a decision about a crop
produced by biotechnology?
6. Would you recommend the use of biotechnology or selective breeding to produce
a new type of crop? Explain the evidence you used to support your decision and
explain at least one trade-off of your decision.
7. Go to: www.futureoffood.com , click on Get involved and resources (selected
web sites)…go to some of the sites and take some notes for your project due Feb.
6th. Decide how you want to demonstrate your thoughts for the project…poster,
video, educational book, web site…