Chapter 11- Introduction to Genetics

Genetics- The scientific study of heredity.

Gene- the factor that are passed from parent to off spring.

Allele- different forms of the genes.


Gametes- Sex cells.

Homozygous- organisms that have two identical allele for a particular gene.

heterozygous- organisms that have two different alleles for the same gene.

Phenotypes- Physical traits.

Genotypes- Genetic Makeup

Incomplete dominance- Cases in which one allele is not completely dominant over another.

Co-dominance- Phenotypes produced by both alleles are clearly expressed.

Polygenic traits- traits controlled by two or more genes.

Multiple alleles- a gene with more then two alleles.

Meiosis- A process in which the number of chromosomes per cell is cut in half threw the separation of homologous chromosomes in a diploid cell.


Homologous- each of the four chromosomes, from the male parent has a corresponding chromosome from the female parent.

Diploid- A cell that contains both sets of homologous chromosomes meaning "Two sets".

Haploid- cells that contain only a single set of chromosomes and therefore a single set of genes.

Tetrad- A structure which contains four chromatids.

Crossing over- it is a process of which chromatids of the homologous chromosomes cross over one another then the cross sections of chromatids are exchanged.

Why is Mendel considered the "Father of Genetics"?
Mendel is the father of genetics because he was the first to write it down.

Mendel's experiment
Were using pee plants to find different colors, shapes, and coat of the seeds shape and color of the pods, and flower position and plant height.
Mendel's experiment was he crossed two pea plants. In the F1 generation they all had dominant traits but in the F2 generation there was a mixture of dominant and recessive genes.

Principle of dominance
Some alleles are dominant and some are recessive.

Principle of segregation
States that a individual inherits a unit of information about a trait from each parent. During gamete formation, the alleles segregate from each other.

Principle of independent assortment
States that the alleles for a trait separate when gametes are formed.

Punnett Squares