Study Notes on Dominance and Genetic Traits

Concept of Dominance
- The phrase "You're red. Own it. Work on that out of your mouth" suggests embracing one's characteristics, which can be tied to the idea of genetic traits.
- In genetic terms, dominance refers to the relationship between alleles of a gene.

Definition of Alleles
- Alleles are different versions of a gene that exist at the same locus on homologous chromosomes.
- For example, in color traits, one allele might code for red, while another might code for blue.
Gene Pairs
- There are typically two alleles for any given characteristic in diploid organisms—one inherited from each parent.
- These can be classified as homozygous (same alleles) or heterozygous (different alleles).

Definition of Chromosomes
- Chromosomes are long strands of DNA that contain many genes.
- Human cells typically have 23 pairs of chromosomes, totaling 46 chromosomes.
Gene Pairing Significance
- The pairing of genes on chromosomes is crucial for heredity and variation in traits. Each gene can determine a particular phenotype (physical appearance).
- Dominant alleles will overshadow recessive alleles in heterozygous pairs in determining phenotype.
- For instance, if the allele for red (R) is dominant over blue (r), an individual with Rr genotype will display the red characteristic.

Dominance: The phenomenon where one allele masks the presence of another.
Alleles: Variants of a gene that influence specific traits.
Chromosomes: Structures within cells that hold genes and hereditary information.
Homozygous vs. Heterozygous: Homozygous denotes an organism with two identical alleles, while heterozygous denotes an organism with two different alleles.

Understanding genetic dominance helps in genetic counseling, agriculture, and evolutionary biology.
The principle of dominance is foundational in studying inheritance patterns and predicting offspring characteristics in genetics.