WHAT IS HEREDITY? The passing down of genes from parent to
offspring
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What are genes? Segment of DNA Determines a trait Trait is
shown as a protein
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Are all genes the same? A trait is a physical characteristic of
your body: Hair Color Height Widows Peak Hitchhikers Thumb Are all
the traits the same?
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Alleles Different forms of a gene Usually represented by a
letter. Each person gets two alleles for a gene ( one from mom/ one
from dad)
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What do alleles mean? Genotype- Combination of alleles in a
person The letters Phenotype What trait the alleles show
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Genotype forms Homozygous- Two of the same allele Heterozygous
Two different alleles in a genotype
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Examples- Mendel and his peas Was a monk Worked with peas to
look at inheritance Was able to develop rules of inheritance
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Mendels findings 1. Each person has two genes 2. Those genes
can be different 3. Only one gene from each parent
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Breeding experiments Determined some relationships between
genes DOMINANT ALLELE- The trait will be expressed if this allele
is present Usually it is the capital letter RECESSIVE ALLELE- The
trait will only show up in phenotype if both alleles are present
Usually it is the lower case letter
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Dominant does not always mean allot! Polydactyly- Having extra
fingers Due to two dominant alleles Not seen allot in
population
