ch 11 genetics. essential vocab true breeding traits hybrids p f 1 f 2
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Ch 11 Genetics
Essential Vocab• True Breeding• Traits• Hybrids• P
• F1
• F2
• Genes
• Alleles
• Genotype
• Phenotype
• Dominant
• Recessive
• Homozygous
• Heterozygous
Gregor Mendel’s Contribution
• “Father of Genetics”
• Worked with pea plants because they are small, easy to grow, and produced large quantities of offspring.
• 7 characteristics are observable on pea plants
• Traits-characteristics like color, height, etc.
What did Mendel do?
• He fertilized the plants (P1) to observe what traits were present in the offspring (F1)
• And….F2
• Self Fertilization• Pea plants self
fertilize
• Cross Fertilization• Two different pea
plants fertilized
Fertilization
Mendelian Inheritance
• Individual’s characteristics are determined by factors that are passed from one parental generation to the next.
• Dominant- masks• What are the dominant
phenotypes?
• Recessive- is masked• What are the recessive
phenotypes?
Annotate and Predict F1
Mendelian Inheritance and Making Predicting
• Allele: A form of a gene. Humans have 2 for each trait.S=Normal Skin (dominant)s=Albanism (recessive)
The combination of them determines what trait we will have.
Genotype Phenotype
Recall: Dominant
• An organism with at least 1 dominant allele will exhibit the dominant trait.
• Shown by CAPITAL LETTERS (S)SS and Ss will have normal skin.
Recall: Recessive
• In order for a recessive trait to be expressed, two copies of that allele must be present.
• Shown by lower case letters (s)
• ss will have albanism
What does it mean? Heterozygous or Homozygous
(Word dissection)• Heterozygous
Ss
• Homozygous
SS and ss
SS homozygous dominant
ss homozygous recessive
Heterozygous or Homozygous Genotypes
Example: skin disorders…
Albanism or Normal Skin?
• S=normal skin
• s=albanismPredicting
expected
genotypes and
phenotypes
• What are the genotypes?
• • •
• What are the corresponding phenotypes?
• • •
What if you wanted to make a prediction for 20 offspring?