Heredity – notes

Topic / Details
Heredity / •Heredity is the passing of ______from parents to offspring
•______is the study of heredity
Gregor Mendel / •Known as the “Father of ______”
•Experimented with “True Breeding” pea plants in his garden
•True Breeding
–Plants that produce ______offspring when allowed to self pollinate
–AKA “Purebred”
•Discovered how ______are passed from parent to offspring in sexual reproduction
Traits / A trait is ______feature or quality in a person
•______- Received from biological parent
–Eye color
–Height
–Blood Type
•______- Acquired during lifetime; not inherited
–Ability to ride a bike
–Scars
–Pierced ears
Some traits can be both!
______- received genes from parents & also affected by sun exposure
Genes / •A gene is a unit of ______
•Occupies a specific location on a ______
•Codes for or determines a specific trait
–Most traits are not coded for by just one gene
Genes and Chromosomes / •Genes are located on ______

•Chromosomes come in pairs
–Each pair is called a homolog
•On each homolog are sites where specific genes are located
Alleles / •Alleles are various forms of the same ______.
•Example 1:
–Gene: Eye Color Alleles: ______
•Example 2:
–Gene: Seed Color Alleles: ______
•Mendel also performed experiments with ______plants
–Hybrids - Plants that were produced by parents with different traits
•In these experiments, he discovered that traits are inherited by parents passing ______to their offspring
•Individuals carry ______alleles for each trait, but only pass down one to their offspring
•One ______is dominant over another .
______Allele: an allele whose trait is always shows up in the organism when the allele is present
–Expressed if only one is present
–Example: brown eye color
______Allele: an allele whose trait is hidden whenever the dominant one is present
–Can only be expressed if two are present
–Example: blue eye color
•Alleles are represented by symbols
–Dominant represented by a ______
•Example: Widows Peak =W
–Recessive represented by the ______letter
•Example: Straight Hair Line = w
•Alleles Interact to Produce Traits
–Each parent contributes ______allele for a given trait
–The ______of alleles from parents can result in varying traits in their offspring

Phenotype and Genotype / •______: An organisms genetic makeup, or alleles an organism has for a trait is its genotype
–Ww, Bb, bb, ww, etc
•______: An organism’s physical appearance, or visible traits is its phenotype.
–Widow’s peak, brown eyes, blue eyes, straight hairline, etc
Heterozygous and Homozygous / •Terms used to describe an organisms genotype
–______– an organism that has two different alleles for a trait is said to be heterozygous
•Example: Ww, Bb
–______– An organism that has two identical alleles for a trait is said to be homozygous
•Example: WW, ww, BB, bb
______
______
______