GENETICS: Genes: The Basic Unit of Heredity
Genetics is the study of genes, heredity, variety, genotypes and phenotype traits in living species. Gregor Mendel was the father of genetics, who studied traits, genotypes and phenotypes, heredity, and developed the Punnet Square.
GENES:
Genes are regions of DNA referred to as loci (location), and portions of chromosomes which encode a protein product, or encode functional RNA, and they are heritable units that are passed from parent to progeny. They are the basis of inheritence of phenotypic traits which influence those traits. They are a DNA code sequence.
GENOTYPE:
The genotype is the inherited genes that express themselves, resulting in a phenotype. These are the genes themselves that control hair color, eye color, other traits, etc...
PHENOTYPE:
A phenotype is a visible, obvious, observable trait or physical characteristic that relies upon gene expression.
TRAITS:
Traits are the visible physical characteristics of organisms. A trait may be a single characteristic, or multiple, quantifiable characteristics. Some examples include:
- Skin color
- Eye color and shape (Blue, Brown, Green, Hazel, Gray, Etc...)
- Hair color (Brown, Black, Red, Blonde, Ash, Etc...)
- Hair texture (coarse, fine, straight, wavy, curly, thick, thin, etc...)
- Face Shape (Round, Oval, Square, Heart, Long, Etc...)
- Ear Shape
- Ear Lobes-Attached, Not Attached
- Widow's Peak (Hair)
- Dimples
- Cleft Chin
- Shape and Length of Fingers and Toes
- Freckles
- Forehead
- Height and Stature
- Frame
- Shape of Lips
- Shape of Nose
- Double-Jointed
- Neck
- Bunions
- Color-Blindness
- Blood Disorders or Characteristics
ALLELES:
Genetic mutations leading to genetic variation in the population; These encode slightly different variations of a protein, or variations of gene sequences, making each individual unique, and resulting in different phenotypic traits. They can be dominant (completely dominant, incomplete dominant, codominant) or recessive. Alleles may be single or may be found in multiples. They are alternate forms of the same gene or same gene location.
MUTATIONS:
DNA:
DNA stands for deoxyribonucleic acid.
RNA:
RNA stands for ribonucleic acid.
CHROMOSOMES:
Chromosomes are the structures or distinct units which carry the genetic information and in which DNA is organized. Each individual chromosome contains a single long DNA molecule associated with numerous proteins, some of which aid in the coiling of the DNA molecule of each chromosome. This is necessary in the reduction of the length of the DNA, enabling it to fit into the nucleus.