PRESENTATION OUTLINE
Goals for Lecture
- Define genotype, phenotype, trait, allele
- Contrast dominant to recessive alleles
- Illustrate inheritance
- Use Punnet square to predict probable genotypes
The Ear as pathway to DNA?
Phenotypes are physical manifestations of inheritable genetic code
Genotypes are genes that code for a physical trait
Traits: the neatly wrapped gifts we could never ask for...
Two donors for the same trait--one from each parent--sometimes different, sometimes the same: both alleles.
We can inherit alleles that never manifest: what we see and use are dominant traits.
Inheritance
- Dominant genotypes get expressed.
- Recessive have a lower probability of becoming phenotypes.
To express recessive traits, only recessive alleles can make a genotype.
Phenotypes are the physical manifestation two alleles that are inherited from parents - one allele from each parent. The traits we see in front of us are dominant alleles expressed, unless someone has two that are recessive.
Draw Your Ideas
- Create a sketch that shows all the ideas you have learned.
- Be creative!
- Be able to explain it to a peer
Types of Genotypes
- Homozygous: alleles are the same.
- Heterozygous: alleles are different.
Punnet Squares predict the chances an offspring has of inheriting a trait: a biologist's Nostradamus.
Click to add more text here
Go predict futures or uncover lineage...carefully.
