4.1 Living Things Inherit Traits in Patterns

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4.1 Living Things Inherit Traits in Patterns

• Mrs. Leos
• October 16, 2020

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SO FAR

• We have learned that
• Cells contain chromosomes
• NOW we will learn about
• How genes for traits are passed from parent to
  offspring
• More about Gregor Mendel
• Dominant and recessive alleles

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Genetics

• The study of gene structure and the patterns of
  inheritance of traits from parent to offspring.

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Traits

• Inherited Hair color, eye color, blood type
  Traits passed from parent to child
• Acquired Ability to read, skills learned

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Genes

• Made of DNA
• Control traits that show up in an organism
• Sections of the chromosome shown here have been
  coloured in. Each section is a piece of DNA
  called a gene.

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Heredity

• Passing of traits (genes) from parent to offspring

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Alleles

• alternative forms of the same gene
• Each allele occupies same position on length of
  chromosome
• Gene for hair color, allele could be blonde,
  brown or red

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Multiple Alleles

• A trait is controlled by more than two alleles
• Blood Type AB AB
• Curly hair straight hair wavy hair
• Brown Eyes Green Eyes Hazel eyes
• Alleles are considered to be co-dominant
• Co-dominant-both show up

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Human Chromosome Number

• 46

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Sex Chromosomes

• X-chromosome
• Y Chromosome

• XXGirl
• XYBoy

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Gregor Mendel- Father of Genetics

• Science of how trait are inherited through
  alleles
• 1856 studied garden peas for height, flower and
  pod position, seed shape, seed color, pod shape,
  pod color, flower color

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Mendel Success

• Mendel figured how traits were transmitted from
  parent to offspring.
• He did not know about DNA, genes or chromosomes

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Phenotype

• Actual characteristics that can be observed
• Physical trait that show up
• ExamplesHeight, size of feet
• How something looks
• Phenophoto

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Genotype

• The genetic makeup of an organism, all the genes
  that an organism has
• Genogene
• Genotype not always obvious

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Principle of Dominant

• Dominant Allele -form that appears or shows up
• Covers up weaker form
• Recessive Allele expressed in phenotype only
  when two copies of it are present in the genotype
• Form that seems to disappear
• Still carried by parent!!

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On page 18

• Demonstration your understanding
• Write your summary