Bio

DNA

Molecule carrying genetic instructions

Chromosome

DNA-containing structure that carries genetic material from one generation to another.

Cell Cycle

Series of events leading to cell division

Interphase

Cell growth and DNA replication phase

Mitosis

Cell division in which the nucleus divides into nuclei containing the same number of chromosomes.

Cytokinesis

Division of the cytoplasm to form two separate daughter cells

Homologous Chromosomes

Pair of chromosomes with genes for the same traits

Meiosis

Cell division produces reproductive cells in sexually reproducing organisms.

Asexual Reproduction

The production of genetically identical offspring from a single parent

Sexual Reproduction

Reproduction involving the union or fusion of a male and a female gamete. Creates variety.

Fertilization

The action or process of fertilizing an egg. Involves the fusion of male and female gametes to form a zygote.

Heredity

Passing of traits from parents to offspring

Gene

DNA segments on a Chromosome that code for a specific trait.

Allele

Variant or different forms of a gene

Genotype

The specific genetic makeup of an organism. (gene types)

Phenotype

The observable physical traits of an organism. (What you see.)

Dominant

An allele whose trait always shows up in the organism when the allele is present.

Recessive

An allele that is masked when a dominant allele is present.

Incomplete Dominance

Heterozygous phenotype blending the two alleles

Codominance

Heterozygous phenotype showing both alleles distinctly

Genetic modification

Altering the DNA of an organism for the purpose of improving the organism.

Genetics

The study of genes and heredity. The passing of traits to offspring.

Law of Independent Assortment

Mendel's Second Law, stating that allele pairs separate from one another during Gamete formation.

Pedigree

A chart or "family tree" that tracks which members of a family have a particular trait.

Traits

A characteristic that an organism can pass on to its offspring through its genes.

Law of Segregation

Mendel's First Law that states that the pairs of homologous chromosomes separate in meiosis so that only one chromosome from each pair is present in each gamete.

Gamete

A mature haploid male or female germ cell that is able to unite with another of the opposite sex in sexual reproduction to form a zygote.

artificial selection

The practice by which humans select plants or animals for breeding based on desired traits.

natural selection

The process by which organisms that inherit advantageous traits tend to reproduce more successfully than other organisms.

Charles Darwin

English natural scientist who formulated a theory of evolution by natural selection (1809-1882)

Five points of Natural Selection

1. Populations have variations

2. Some variations are favorable

3. More offspring is produced then survive

4. Individuals that survive will have more favorable traits

5. A population will change over time