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Genetics
Chapter 9
Vocabulary
*Heredity – The transmission of traits from parents to
offspring.
* Traits- a specific characteristic of an organism (Example:
Brown hair, blue eyes, multicellular)
*Characteristic- a distinguishing mark, feature or attribute
(Examples: hair color, eye color, cells)
Heredity
Heredity
Heredity
Characteristic
Trait
*Pure – Always produce offspring with that trait.
*Strain – Describes all plants pure for a species.
PURE
STRAIN
(These are 2
different types
of flu strains)
*Allele –Each of several alternative forms of a gene
~represented by letters
*Genotype-Genetic makeup of organism (you can not see
someone’s genotype)
*Phenotype- External appearance (the visible trait)
Allele
Principles of Genetics
*Principle of Dominance & Recessiveness
~One factor in a pair may mask the other, preventing it from
having an effect.
*Principle of Segregation
~Each reproductive cell receives one factor for a trait,
therefore 2 factors separate during egg & sperm formation.
*Principle of Independent Assortment
~Factors for different characteristics are distributed to
reproductive cells independently.
Which color is dominant? Which is
recessive?
What is the allele for green?
What is the allele for yellow?
Click image for videostart at 5:25
Human Traits
Punnett Squares