4-2: Kingdoms

Which domain do humans fall in?

We are part of the Eukarya domain.

domain

A taxonomic category above the kingdom level. The three domains are Archaea, Bacteria, and Eukarya.

Kingdom: Eubacteria

All bacteria used to belong to one kingdom, but they have since been broken into two. Eubacteria are mostly single-celled prokaryotes that lack a nucleus as well as some other organelles. They are single-celled organisms that have a long lash-like appendage called a flagellum used for locomotion. They are present in all environments and can be helpful or harmful. Eubacteria that help the production of yogurt are useful, while the ones that can give you strep throat are literally a pain in the neck.

Mode of Nutrition (five chief characteristics)

An organism can be classified into a kingdom based on its mode of nutrition. For example, all organisms that produce their own food are called autotrophs. All organisms that eat plants or other rely on other organisms for food fall into the category of heterotrophs. Some Eubacteria, Protista, and Archaebacteria fall into both categories. Animals are clearly heterotrophic, while plants are the only true autotrophs. Plants create their own food using chlorophyll and the process of photosynthesis.

Motility (five chief characteristics)

Another characteristic that can be helpful in classification is motility, or the ability to move. Organisms belonging to the kingdom Animalia move and are called motile. Organisms that belong to the kingdoms Plantae and Archaebacteria do not move and are called non-motile or sessile. Eubacteria can move using a whip-like structure called flagella, and other microorganisms belonging to the kingdom Protista can move if they possess a flagella or hairy structures called cilia, as shown in the picture above.

Kingdom: Archaebacteria

Archaebacteria are extreme bacteria. They are bacteria that can survive in harsh environments, like the hot spring shown here, or where there is no oxygen. They are considered anaerobic (without oxygen) bacteria. These bacteria love hot temperatures and can be found in the hot springs of Yellowstone National Park. Some love salt environments and can be found in the Utah salt lakes or the Dead Sea in Israel. They can even be found in deep sea thermal vents that spew out sulfuric acid.

How are all the kingdoms reliant on each other?

Each organism has a specific purpose, and most rely on each other to perform that purpose. Even E. coli in a cow's stomach helps its digestion, which in turn gives us milk to drink. E. Coli out of place is dangerous, but in its place, it is essential.

What are the various kingdoms of life?

Eubacteria, Archaebacteria, Protista, Fungi, Plantae, Animalia

kingdom

First and largest category used to classify organisms.

Kingdom: Fungi

Fungi look like plants as they sprout from the ground; however, they cannot carry out photosynthesis or make their own food. They are dependent on dead and decaying matter on the ground and live off other plants. Examples include mildew, mushrooms and mold.

How would you define humans using these five characteristics?

Humans are characterized as eykaryotic, multicellular, hetereotrophic, motile, sexual reproductive.

Humans fall in the Eukarya domain. Which kingdom do humans fall into?

Humans belong in the Animalia kingdom.

The Three Domains of Life

Life is a category that includes all entities that have self-sustaining processes within them. Scientists think that all life came from primitive prokaryotic cells that served as a common ancestor from which bacteria and archaea diverged and formed eukaryotes. Scientists have placed all organisms into three broad domains (all organisms that are alive and share basic molecular similarities) - Bacteria, Archaea, and Eukarya. Organisms of the three domains have basic molecular similarities, like the presence of DNA and plasma membranes. These similarities are believed to exist because of a common ancestor. However, important differences exist among the three domains. These differences occur mainly because of the way the cells are developed.

Kingdom: Protista

Protista are all unicellular organisms that do not belong to the category of Bacteria, Archaebacterial, or Fungi. Protista, also called protists, are complex but unicellular, which separates them from other more simple unicellular organisms. Classic examples include the red algae in the sea and the slime mold and green algae in ponds and other wet areas.

Cell organization (five chief characteristics)

Scientists also look to see how the cells are organized. If the organism has many cells and the cells are organized into tissues and organs then it's a multicellular (many cells) organism. The absence of such organization shows it's a unicellular (single cell) organism. Multicelluar organisms are placed in Plantae, Animalia, or Fungi, while organisms that are unicellular are placed in Eubacteria, Protista, or Archaebacteria.

Cell type (five chief characteristics)

Scientists study the cells of each organism under a microscope and look for the presence of organized organelles such as a nucleus, like the cell on the left in the image. The presence of organelles indicates that the organism is a eukaryote. Without organelles, like the cell on the right in the image, the cell is a prokaryote. Organisms possessing prokaryotic cells are placed in the eubacteria or archaebacteria kingdoms, while organisms possessing eukaryotic cells are placed in one of the other four.

Reproduction (five chief characteristics)

Taxonomists use the type of reproduction to classify organisms as well. There are two types of reproduction: sexual and asexual. Asexual reproduction does not require a male and female. Mitosis is the process underlying it. Organisms that undergo asexual reproduction have been placed in the kingdoms of Eubacteria and Archaebacteria. Sexual reproduction, however, involves the union of male and female gametes. Meiosis is the first process, in which the gametes are formed, each with half of the total chromosomes required. This is followed by fertilization, where the correct number of chromosomes is restored. Then, mitosis begins forming new cells, each with the same number of chromosomes. Organisms relying solely on sexual reproduction have been placed in kingdom Animalia. Organisms that rely on both sexual and asexual forms of reproduction are placed in the kingdoms Plantae, Protista, and Fungi.

Kingdom: Animalia

There are more than one million species of animals on earth. Some have backbones (vertebrates) and some do not (invertebrates). They inhabit all kinds of environments and are a dominant group of life on earth. They are multicellular and have sophisticated organ systems. Examples include insects, birds, whales, reptiles, sponges, and elephants.

Kingdom: Plantae

There are over 25,000 species of plants on earth. This kingdom contains multicellular organisms including flowering and non-flowering plants. These "lungs on earth" regulate the amount of oxygen on earth through photosynthesis using a green pigment called chlorophyll. From the lowly green grass on the ground to the giant sequoia trees of California, plants are also a dominant presence on earth.

Which of the following characteristics is unique to the kingdoms Eubacteria and Archaebacteria?

asexual reproduction only

What characteristics must be observed in order to classify a pond creature's place in a specific kingdom?

its cell number and cell type