A3.1 Diversity of Organisms

Taxonomy

The science of classifying organisms.

Morphology

A classification system based on observable physical traits, developed by Linnaeus.

Morphological Species Concept

Defines species as groups based on morphological similarities and differences.

Binomial Nomenclature

Scientific naming system where each organism is given a two-part name, genus (uppercase) and species (lowercase), e.g., Homo sapiens.

Biological Species Concept

A group of organisms capable of reproducing with each other to produce fertile offspring.

Population

A group of the same species, in the same place, at the same time.

Speciation

The splitting of one species into two or more species.

Karyotype

The number and type of chromosomes found in a cell.

Karyogram

A diagram or photo of chromosomes found in a cell.

Homologous chromosomes

Chromosomes that have the same sequence of genes and are the same length.

Trisomy 18

Edwards syndrome characterized by body development issues and growth problems.

Trisomy 13

Patau Syndrome associated with intellectual disability and physical abnormalities.

Genome

Includes all the genetic information of an organism required for growth and development.

Polymorphism

The existence of multiple forms of a particular trait within a species, often due to mutations.

Genome Size

Total amount of DNA measured in nitrogen base pairs (bp); ranges from kilobases to gigabases.

DNA barcode

A DNA sequence that uniquely identifies each species, aiding species identification.

Horizontal Gene Transfer

The transfer of genes between unrelated species, commonly occurring in bacteria.

Flaws of the Biological Species Concept

Does not account for asexual reproduction and horizontal gene transfer.