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• BTEOC, SWBAT:
predict possible outcomes of various genetic combinations using notes and monohybrid practice problems
What is Genetics?
• Genetics is the study of heredity and variation
• Heredity is how genes and traits are passed from one generation to the next, and is the reason why offspring tend to look like their parents and siblings
• Variations are differences in the physical traits of individuals
• Traits are physical characteristics
Who is Gregor Mendel?
• Father of genetics
• Austrian monk of the mid 1800’s
• HIS WORK: Studied heredity in the garden pea plant
What is the Law of Segregation?
• Parents only pass one copy of each gene that they carry to each of their offspring
• Random chance determines which copy of the gene is passed each time a sperm or egg is made by meiosis
What is the Law of Independent Assortment?
Genes for different traits assort independently during gamete formation (because chromosomes line up randomly in Meiosis I)
What is the Principle of Dominance?
• When Mendel crossed plants with different traits, only one of the traits showed up in the offspring
• He concluded that some traits are dominant over other traits
What are Dominant and Recessive Traits?
• Dominant traits are always expressed if the allele (copy of a gene) for that trait is present
• Recessive traits are only expressed when the dominant allele for that trait is NOT present
• BTEOC, SWBAT:
predict possible outcomes of various genetic combinations using notes and monohybrid practice problems
Where are genes located?
• Genes are located on chromosomes, which are found in the nucleus of the cell
• Each chromosome is made of a very long molecule and PROTEINS that help to condense the DNA
Where are genes located?
Each gene has a specific location, called a locus, where it is found on a specific chromosome
If we all have the same genes on the same chromosomes, then why are we all so different?
Map of genes on the human chromosomes
What are Alleles?
• Alleles are alternate forms of a gene• Each individual has two copies of each gene, or two
alleles for each gene• One allele is on a chromosome inherited from mom• One allele is on a chromosome inherited from dad• The two alleles may be identical or different
What is a Phenotype?
• The phenotype is the physical traits of an individual• Phenotypes are determined by genes and environment
Curly Hair
Free Earlobes
Yellow Seeds
Red Flowers
What is a Genotype?
The genotype is the genetic make-up of an individual, or the alleles that an individual carries for a gene or genes