Chapter 12 Vocab

Genetics

Scientific study of biological inheritance.

Fertilization

Male and female reproductive cells join in a process known as this to produce a new cell.

Trait

Specific characteristics, like seed color or plant height.

Hybrids

Off-spring of crosses between parents with different contrasting characteristics.

Genes

An individual’s characteristics are determined by factors that are passed from one parental generation to the next.

Alleles

The different forms of a single gene.

Principle of dominance

Mendel’s second conclusion. States that some alleles are dominant and others are recessive.

Segregation

Seperation.

Gametes

Formation of the reproductive cells.

Probability

Likelihood that a particular event will occur.

Homozygous

Organisms that have two identical alleles for a particular gene.

Heterozygous

Organisms that have two different alleles for the same gene.

Phenotype

Physical traits.

Genotype

Genetic makeup.

Punett square

Mathematical probability to help predict the genotype and phenotype combinations in genetic crosses.

Independent Assortment

States that genes for different traits can segregate independently during the formation of gametes.

Incomplete Dominance

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

Codominance

Situation in which the phenotypes produced by both alleles are clearly expressed.

Multiple alleles

A gene with more than two allels.

Polygenic Traits

Many genes.

Homologous

Each of the four chromosomes from the male parent has a corresponding chromosome from the female parent.

Diploid

A cell with two sets of homologous chromosomes.

Haploid

Single set of genes.

Meiosis

Process in which the number of chromosomes per cell is cut in half through the seperation of homologous chromosomes in a diploid cell.

Tetrad

Pairing forms a structure.

Crossing-over

Bits and pieces of the homologous chromosomes are exchanged.