Introduction to Gentetics
Genotype
Genotypes are allele set that determines the expression of a trait or characteristics and is a gene combination of at least two letters.
Examples
- TT, Tt, tt
- DD, Dd, dd
- RR, Rr, rr
Phenotype
Phenotype is the physical appearance of an organism through the expression of its genes.
Examples
- genotype- Ee / phenotype- green eyes
- genotype- ff / phenotype- blonde hair
- genotype- YY / phenotype- widows peak
Homozygous
Homozygous means to code for two identical alleles with the same trait.
Examples
- HH
- DD
- rr
Heterozygous
Heterozygous is a pair of genes where one allele is dominant and one is recessive.
Examples
- Hh
- Ll
- Tt
Dominant
Dominant allele is the trait that hides or masks the recessive gene and is represented through a capital letter.
Examples
- TT
- ZZ
- LL
Recessive
Recessive allele is the trait that is taken over by a dominant gene. The trait can still show if paired with another recessive allele.
Examples
- kk
- rr
- ee
Questions
“How can someone predict the traits of offspring?”
- You can predict the traits of an offspring by using a punnet square and inputting what the parent traits are.
- It is important to study this to understand how traits are given to offspring and what determines how they get those traits.
Sources
- http://upload.wikimedia.org/wikipedia/commons/thumb/1/17/Punnett_square_mendel_flowers.svg/2000px-Punnett_square_mendel_flowers.svg.png
- http://www.biology-online.org/dictionary/Genotype
- http://sciencelearn.org.nz/Contexts/Uniquely-Me/Science-Ideas-and-Concepts/Genotype-and-phenotype
- https://room114.wikispaces.com/file/view/CelebTable1.gif/32179569/CelebTable1.gif
- http://feistyhome.phpwebhosting.com/punnett4.gif
- http://education-portal.com/cimages/multimages/16/genotypes_phenotypes.png
- http://www.medicinenet.com/script/main/art.asp?articlekey=3105