Gregor Mendel and Genetics

Important terms to know for Genetics

Heredity and Genetics Vocabulary

Trait – A characteristic caused by genetics or the environment

Chromosomes – Long strands of DNA that contain thousands of genes

Genes – Part of chromosome that controls a trait(30,000 in humans)

Allele – Different forms of genes

Recessive allele – Only see this trait if two are present

Dominant Allele – Always shows its trait

Hybrid – Has two different alleles for same trait

Purebred – Has two identical alleles for same trait

Probability – The likelihood that an event will occur

Punnett Square – A chart that shows all possible combinations of alleles between two organisms

Phenotype – The visibly expressed trait (ie. blue eyes)

Genotype – The allele combination for a trait (ie. Bb or bb.)

Homozygous – Two identical alleles (Purebred)

Heterozygous – Two different alleles (Hybrid)

Codominant Alleles – Neither allele is dominant(ie. Blood types or spotted dog)

Incomplete Dominance – The dominant alleles mix – (Green flower from blue and yellow alleles)

Meiosis – Process that creates sex cells with one copy of each gene or half the number of chromosomes

Cross-Fertilization – A gamete(sex cell) from each parent gives one allele for each trait to make a new organism(humans)

# of human chromosomes – 23 pairs or 46 chromosomes

X and Y – Human chromosomes that determine gender

Mutation – When a chromosome is not copied correctly

Carrier – Someone who has one recessive allele for a trait but doesn’t show it.

Pedigree – A chart that tracts a particular trait in a family

Karyotype -  A picture of all the chromosomes of a cell

Genome – All the DNA in one cell of an organism

Genotype – An analysis of a genome to determine inherited traits