Levels of Classification Flashcards

Levels of Classification

• Domains serve as the highest rank in the biological classification system, including Eukarya, Bacteria, and Archae.
• Kingdoms categorize organisms under domains; for instance, Animalia is a kingdom under Eukarya.
• Phylum groups organisms based on major body plans, such as Chordata for animals with a backbone.
• Class further subdivides phylum; Mammalia includes all mammals.
• Orders cluster species based on similar characteristics; Primates include humans and monkeys.
• Families group closely related organisms, like Hominidae, which includes great apes and humans.
• Genus consists of closely related species; Homo is the genus for humans.
• Species is the most specific classification level, defining interbreeding populations; for humans, it is sapiens.

Human Classification

• Humans are classified within the following hierarchy:
  • Domain: Eukarya
  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Mammalia
  • Order: Primates
  • Family: Hominidae
  • Genus: Homo
  • Species: sapiens

Binomial Nomenclature

• A two-part naming system that provides a unique name to each species.
• The genus name is capitalized, while the species name is not.

Biological Species Definition

• A group of organisms capable of interbreeding and producing fertile offspring.
• Example: Horses and donkeys can mate to produce mules, which are sterile.

Hybrid Organism

• An organism resulting from crosses between species is termed a hybrid.

Domains of Life

• Three domains: Archae, Bacteria, and Eukarya.

Characteristics of Domain Archae

• Prokaryotic and the most ancient life form.
• Often found in extreme environments such as hot springs.
• Contains one kingdom: Kingdom Archae.

Characteristics of Domain Bacteria

• Prokaryotic and distinct from Archae based on habitat, cell wall structure, and RNA.
• Contains one kingdom: Kingdom Bacteria.

Characteristics of Domain Eukarya

• Eukaryotic and includes four kingdoms:
  • Kingdom Protista
  • Kingdom Plantae
  • Kingdom Fungi
  • Kingdom Animalia

Characteristics of Fungi

• Can be multicellular or unicellular.
• Heterotrophic, feeding on the growth of other organisms.
• Examples include mushrooms and molds.

Characteristics of Protista

• Comprises both multicellular and unicellular organisms.
• Can be heterotrophic or autotrophic, producing their own food.
• Examples include kelp and amoeba.

Characteristics of Plantae

• Exclusively multicellular and autotrophic.
• Organisms produce their own food via photosynthesis.
• Examples include trees and flowers.

Characteristics of Animalia

• Exclusively multicellular and heterotrophic.
• Organisms consume other organisms for energy.
• Examples include tigers and giraffes.

Vestigial Structures

• Evolutionary remnants that hint at an organism's ancestry.
• Examples include whale pelvic bones and the human appendix.

Homologous Structures

• Anatomically similar structures that may serve different functions.
• Example: Vertebrate forelimbs have similar bone structures.

Analogous Structures

• Structures that serve similar functions but do not share a common evolutionary origin.
• Examples include the wings of birds and insects.

Differences Between Eukarya and Prokarya

• Prokaryotes are single-celled organisms without a nucleus, whereas eukaryotes have a double-helix DNA structure and contain a nucleus.

Fungi Classification

• Fungi belong to the kingdom Fungi and are categorized as heterotrophic organisms.

Specific Organisms and Their Kingdoms

• Chinook Salmon: Animalia
• Coral: Animalia
• Amoeba: Protista
• Mold: Fungi

Homologous Example

• The bat wing is a homologous structure compared to the human arm.