Genetics Vocabulary Words to know!

Gregor Mendel His work contributed to the discovery of inheritance. Worked with pea plants

Genetics Definition: The study of heredity. Example: If you study genetics you study how traits are passed down from parents to children.

Heredity Definition: The passing of traits from parents to offspring. Example: Both father and son can roll their tongue.

Trait Definition: a characteristic that occurs in 2 or more forms. Example: Dimples are an example of a trait.

Alleles Definition: Different forms of a gene for a single trait. Example: Blue eyes and brown eyes are examples of different alleles for eye color.

Gene Definition: A section of a chromosome that holds the instructions for a trait. Example: Humans have 20,000 genes in their 46 chromosomes.

Dominant Definition: The form of a trait (allele) that hides the recessive trait. Example: The ability to roll your tongue is caused by a dominant gene.

Recessive Definition: The form of a trait that is hidden. Example: A white tiger is a result of a recessive gene.

Phenotype Definition: Physical appearance of an organism. Example: Phenotypes are easy to understand because they refer to something you can see in an organism.

Genotype Definition: Genetic makeup of an organism. Example: BB, Bb, and bb are all examples of genotypes.

Heterozygous Definition: Genotype made of two different alleles. Example: “Rr” is an example of a heterozygous genotype.

Homozygous Definition: Genotype made of two of the same alleles. Example: “RR” or “rr” are both homozygous genotypes. Other Form: Homozygous Dominant, Homozygous Recessive.

Probability Definition: Chance of an event occurring. Example: There are 13 hearts in a deck of cards so the probability of getting a heart is 13/52.

Punnett Square Definition: A tool used to predict the chance of traits occurring in offspring. Example: The chance of getting Bb is 50%.

Monohybrid Definition: A cross involving just one trait. Example: Bb x bb is a monohybrid cross because it involves just one trait.

Dihybrid Definition: This is a type of cross that involves 2 different traits. Example: Dihybrid crosses are complex because they involve 2 different traits.

P1 Generation Definition: Parent generation used in a cross. Example: The P1 generation is the first generation because it represents the parents.

F1 Generation Definition: The offspring of the P1 generation. Example: The children from the P1 generation are the F1 generation.

Phenotypic Ratio Definition: The ratio of the number of offspring with the dominant trait to the number of offspring with the recessive trait. Example: 3:1 is the phenotypic ratio for this cross.

Genotypic Ratio Definition: A ratio between the different genotypes in a cross. Example: In this genotypic ratio there is only 1 plant that shows both recessive traits.