Download Fundamentals of Genetics

Fundamentals of Genetics: Mendel’s Legacy
Directions: Watch and listen to the Prezi as “Akerbomb” presents it. The format below will follow the presentation
closely. Listen for prompts for when and where to fill in the appropriate information.
Objectives:
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Describe the steps involved in Mendel’s experiments on garden peas.
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Who is Mendel?
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What were his garden peas?
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What were his experiments with garden peas?
Distinguish between dominant and recessive traits.
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What is a dominant trait?
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What is a recessive trait?
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How are they alike and how are they different?
State two laws of heredity that were developed from Mendel’s work?
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Law of Segregation:
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Law of Independent Assortment:
Explain the difference between an allele and a gene.
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Allele:
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Gene:
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Describe how Mendel’s results can be explained by scientific knowledge of genes and chromosomes.
Mendel’s Observations
Characteristics or traits are
determined by factors occurring in
pairs.
Modern Principles of Genetics
Traits are determined by _______________ occurring on homologous
chromosomes. Each form of a gene is called an _______________.
Some traits are dominant while
others are recessive.
The effects of one active gene may mask the expression of another
inactive gene. Two active genes may share expression called:
Codominance –
Incomplete dominance –
The factors that parents have from
their parents, separate during the
formation of the egg and sperm
(meiosis) for offspring.
One pair of factors are separated
independently from the separation
of another pair.
Principle of Segregation: __________________ on homologous
chromosomes separate during anaphase 1 of ________________..
Law of __________________________ assortment: The lining up and
separation of genes on one set of homologous chromosomes is
independent of the separation of genes on another set of homologues.
Trait
Phenotype
Position of flower
along stem
Axial
Height of plant
Pod appearance
Pod color
Seed texture
Seed color
Flower color
Allele
symbol
Genotype
Terminal
Tall
Short/dwarf
Inflated
Constricted
Green
Yellow
Smooth
Wrinkled
Yellow
Green
Purple
White
Punnett Square Practice: Read the word problem and then use the information to complete the punnett square.
Always answer question with both phenotype and genotype statistics.
1) A plant that is homozygous for yellow seeds is crossed with a plant that is homozygous for green seeds. What
percentage of the F1 generation would you expect to have yellow seeds?
2) A plant that is heterozygous for tall stem length is crossed with a plant that has dwarf stem length. What
percentage of the F1 generation would you expect to have dwarf stem length?
3) A plant that has wrinkled seeds is crossed with a plant that is heterozygous for round seeds. What percentage
of the F1 generation would you expect to have round seeds?
4) A plant that is heterozygous for purple flowers is self-pollinated (crossed with itself). What would be the
expected phenotype ratio of the F1 generation?
5) A plant that is homozygous for tall stem length is crossed with a plant that is homozygous for dwarf stem length.
What would be the phenotype of all the offspring in the F1 generation?
6) A gardener has a plant that produces yellow seeds. If he does a test cross, what would be the genotype of the
plant he would use for the test?
7) If the test cross described above produces offspring that are 48% yellow and 52% green, what is the genotype of
the original plant?