Name ____________________________________________ Period _________ Date ______________
Chapter 11 -- Genetics
Gregor Mendel
 Austrian monk that had an interest in science
 Worked with plants at the ______________________
 Had a background in _______________ and ________________
 Proved valuable research in _______________________
 Taught high school science
 Kept a garden plot of _________________
 Observed _________characteristics of pea plants
 Each trait had _________ possible outcomes
 Recorded plant seeds and planted them
 Noticed __________________ plants all came from _________________ seeds
 White plants also grew from these seeds
 Noticed a _____________________ in height
 Began his study on controlling ___________________________
Pollination
• When ____________________ grains produced by male part of a flower
are _________________ to female part of the flower
• Self-Pollination
• When _________________________ is transferred from anthers to stigma
of same plant or another flower on ___________________ plant
• Cross Pollination
• When pollen is transferred between __________ plants
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• To control the pollination, Mendel removed the _____________________ of the
pea plants
• Used pollen from anthers to ________________ pollinate and control traits
passed to next generation
Mendel’s Experiments
• True-breeding plants
• Plants that only produce offspring with _____________characteristics
every time
• Ex: true-breeding yellow pod plants only produced yellow
pods in next generation
• Mendel used _________________________ plants to test for passed on traits
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P Generation
• Mendel himself cross-pollinated pairs of plants that were true-breeding
parents
• Known as ______ generation
F1 Generation
• Mendel recorded next generation of pea plants characteristics
• Known as ______ generation
F2 Generation
• The F1 generation were able to self-pollinate to make a new generation
• Known as ______ generation
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Mendel’s Results
• Recessive and Dominant Traits
• ________________________ traits were seen more often
• These traits __________________or dominant other traits
• Ex: _________________eyes are dominant over _____________
• Recessive traits are seen less often
• Law of Segregation
• Law states that pair of factors is _________________________ during
formation of gametes (meiosis)
• Making ____________________________ (sperm and egg) produces
haploid cells with only one half the amount of chromosomes
• Law of Independent Assortment
• Traits do not necessarily appear ________________________
• The trait for pod seed color is not associated with the flower color
• They are ___________________________ traits
• ________________________ separation during meiosis
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Mendel’s Conclusions
• Molecular genetics
• Study of __________________on the ____________________________level
• Factors that Mendel was testing are known as ________________ on a
chromosome
• Area of a chromosome that determines a specific ____________
• Alleles
• Alleles are represented with letters
• Ex: Dominant (______) recessive (______)
Genotype/Phenotype
• Genotype
• ___________________ makeup of an organism
• Consists of _______ allele letters
• Can determine ______________________ from genotype
• Ex: Brown eyes (BB or Bb), blue eyes (bb)
• Phenotype
• ____________________ appearance that is seen
• Phenotypes ___________ always tell you the genotype
• Ex: brown or blue eyes
• Homozygous
• When the two alleles are _______________
• Ex genotype: BB or bb
• Heterozygous
• When the two alleles are ________________________
• Ex genotype: Bb
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Probability
• Likelihood that a specific event will occur
• Can be a _________________, _________________ or _____________________
• Ex: out of 8,023 plants, 6, 022 were yellow and 2,001 were green
• 6022/8023 = 0.75
2001/8023 = 0.25
or ¾ or 75%
or ¼ or 25%
Punnett Squares
• Monohybrid Cross
• Cross of _______________ characteristic from two organisms
• Ex: eye color
Mom: BB (brown) Dad: bb (blue)
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Example 1 -- Homozygous x Homozygous
• Ex: Homozygous purple plants x homozygous white plants
• Genotypes:
Example 2 -- Homozygous x Heterozygous
• Ex: Homozygous black guinea pigs x heterozygous black guinea pig
• Genotypes:
Example 3 -- Heterozygous x Heterozygous
• Ex: Heterozygous black coat rabbit x Heterozygous black coat rabbit
• Genotypes:
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Testcross
• To test for _______________________ genotype
• Unknown individual is crossed with a _____________________________
recessive individual
• If the results are only phenotype _______________________, unknown
individual is homozygous dominant
• If the results show some phenotype _______________________, unknown
individual is heterozygous
Dihybrid Crossing
• Dihybrid Cross
• Cross of _____________ characteristics
• Harder to predict because more _________________________ results
Example 1 -- Homozygous x Homozygous
Ex: Homozygous wrinkled, green peas x homozygous round, yellow
Genotypes:
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Example 2 -- Heterozygous x Heterozygous
Ex: Heterozygous round, yellow peas x Heterozygous round, yellow peas
Genotypes:
Example 5 -- Incomplete dominance
• When the phenotype of a heterozygous individual is an in
between of the two parents
• Ex: four o’clock flowers
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Example 6 -- Codominance
• When ___________ alleles are expressed at the ________________ time
• _______________ possible phenotypes
• Both alleles are _________________________
• Ex: Red & white flowers
Codominance
• Blood Typing
• There are __________ possible blood types
• _______________________________
• _______ and _______ are both dominant
• _______ is recessive
• Use letter ______ to show genotype
Polygenic Inheritance
• A trait that is influenced by ___________________ genes
• Poly = ________________
• Genic = _______________
• Usually show degrees of _______________________
• Ex: skin color, height
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Multiple Alleles
• Genes with __________ or more ____________________
• Ex: Blood types (IAIB,IAIA, IBIB, IAi, IBi, ii)
• This shows both ______________ and ____________ alleles
Chromosomes
• Thomas Hunt Morgan
• Worked with fruit flies (Drosophila) and noticed they have ______
pairs of chromosomes
• Males and females have one pair of different sized chromosomes
(______ and _______ chromosomes)
Meiosis
• Process of making ___________________
• Males = _______________
• Females = _________________
• Gametes are ______________ cells
• ____________ chromosomes (no pairs!)
• End result is _____ _______________________ daughter cells
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Meiosis I
• Prophase I
• DNA condenses to _______________________
• Spindle fibers from ________________________ appear
• _________________________ chromosomes pair up called a synapse
• Pair of homologous chromosomes is called a _________________
• Tetrads _________________________ genetic info to mix up possible
genes
• Called _______________ ______________
• When tetrads cross over, they create recombinant DNA
• This is the reason why daughter cells are _____________________
• Metaphase I
• __________________________ line up randomly along middle of cell
• Anaphase I
• Tetrads ______________________ to opposite poles of the cell
• This is a ___________________________ process
• Random assortment of genes
• Telophase I & Cytokinesis I
• Chromosomes reach opposite side of the cell and ___________________
begins
• Creates ________ _________________________ daughter cells
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Meiosis II
• Prophase II
• Nucleus ____________________________
• Chromosomes begin to move
• _________________________ fibers form
• NO DUPLICATION OF CHROMOSOMES!
• Metaphase II
• _____________________________ line up in the middle of the cell
• Anaphase II
• Chromosomes split ___________________ to sister chromatids
• Telophase II & Cytokinesis II
• Nuclear membrane _________________________
• Chromosomes break down to _______________________
• Creates 4 non-identical daughter cells that are ______________________
• Only one sister chromatid of each chromosome
Sexual Reproduction
• Production of offspring through __________________________ and the union of
a sperm and egg
• After fertilization, the egg is called a _____________________
• The zygote undergoes division and becomes a new ________________________
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Mitosis vs. Meiosis
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