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14 Cards in this Set
- Front
- Back
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Gregor Mendel
Born in 1822 Austria Grew up on a farm He became a monk as an adult He was the gardener at the monastery. This is where he studied peas! |
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Peas were good to study because they:
1. Grow quickly 2. Usually self-pollinating Self-pollinating plants contain both the male and the female reproductive structures. |
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Mendel studied only one characteristic at a time. He used true-breeding plants. True-breeding plants always produce offspring with the same trait.
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Mendel also used cross-pollination. In cross-pollination, anthers are removed from one plant so it can not self-pollinate. Then pollen from another plant is used to fertilize the plant with no anther. This allows scientists to select which pollen will fertilize which plant.
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In Mendel’s 1st experiment:
He found that one trait always appeared in the first generation but the other trait seemed to vanish. Dominant Trait: The trait that appears Recessive Trait: Trait that recedes into the background/seems to disappear |
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In Mendel’s 2nd experiment:
He allowed the 1st generation to self-pollinate. The lost trait reappeared! |
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Mendel decided there must be two sets of information, probably one from each parent. The information form one parent is a gene.
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The two forms of a gene are known as alleles.
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Genotype: inherited combination of alleles (what the genes are and say) Ex. TT or Tt
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Phenotype: The organisms appearance based on it’s genotype. Ex. Tall
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Punnett Squares
Graph/Tool used to visualize all the possible combinations of alleles. Dominant is symbolized by a capital letter. Recessive is symbolized by a lower case letter. |
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Homozygous: both alleles are dominant or both alleles are recessive. Ex. TT or tt
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Heterozygous: one allele is different. Ex. Tt
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Example:
Homozygous Dominant would be written like this: TT Heterozygous would be written like this: Tt Homozygous Recessive would be written like this: tt |
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