Aim
The aim of this study is to understand how dominant and recessive genotypes can affect phenotypes.
Objectives
- Define genotype and phenotype
- Compare and contrast the genotype of dominant and recessive traits
Genotype vs. Phenotype
- Genotype: This refers to the genetic makeup of an organism, which is determined by its DNA.
- Phenotype: This is how something looks, which is the actual characteristics that can be observed, such as physical traits that "show up."
Genes
- Made up of DNA to determine traits
- Transferred from parent to offspring
Alleles
Alleles are the different options or alternative forms of the same gene. For example, when it comes to the gene for hair color, the alleles can be Blond, Brown, Black, or Red.
- Dominant Allele: This is the form that appears or shows up.
- Recessive Allele: This is expressed only when two copies of it are present in the genotype.
Dominant vs Recessive Genotypes
- Homozygous Dominant: Represented by Ww or WW, which leads to a widow's peak.
- Heterozygous: In this case, an organism's genes for a trait have different alleles, with the offspring inheriting one dominant gene and one recessive gene (e.g., Tt, Aa, Rr).
- Homozygous Recessive: In this scenario, the organism's genes for a trait have the same alleles, and the offspring inherit two recessive genes (e.g., tt, aa, rr).
Chromosome
- In the case of an organism's genes for a trait being the same alleles, the offspring inherit two dominant genes (one from each parent) (e.g., AA, TT, RR).
Example of Alleles and Traits
- Hair Color: When it comes to hair color, possible genotypes include HH (homozygous dominant), Hh (heterozygous), and hh (homozygous recessive).
- Eye Color: An example of alleles and traits can be seen in the alleles for eye color, where B represents the allele for brown eyes (dominant over the b allele), and b represents the allele for blue eyes (recessive to the B allele).
Phenotypes
The phenotypes are the observable physical traits resulting from the genotype. For example, some individuals may have brown eyes (BB or Bb) while others have blue eyes (bb).
By understanding the concepts of dominant and recessive traits, it becomes clear how genotypes can influence the phenotypes in different individuals. This insight is valuable for various fields, such as biology, genetics, and medicine, as it provides a foundation for understanding inherited traits in humans and other organisms.
