In 1959, American biologist R. H. Whittaker introduced a classification system consisting of five primary kingdoms, namely plants, animals, fungi, protists, and monera. The animalia kingdom encompasses all living or extinct animals, with humans serving as an example. Humans depend on various elements within each of the five kingdoms for sustenance. The monera kingdom represents the lowest division of rhizopods and includes bacteria, both beneficial and harmful, some of which resemble amoebas and lack a nucleus. Plantae comprises all living or extinct plants and is essential for humans and most animals in the animalia kingdom, particularly herbivores and omnivores, to obtain energy and nutrients. The fungi kingdom consists of heterotrophs, such as paramecia, which cannot produce their own food. Within the Plantae kingdom, multicellular autotrophs are found, indicating that they do not produce their own food. Protista refers to a group of simple organisms known as protists that exhibit characteristics of both plants and animals. Most protists are unicellular and can only be observed under a microscope, although some consist of multiple cells.
Even within the same kingdom, all organisms have distinct differences. Each species has adapted specific traits to thrive in its environment. Their physical structure, reproductive methods, and diet are all influenced by their habitat. There are several examples of diverse species, such as sequoia redwood trees from the Plantae family, protists from the protista group (comprising small organisms), arthropoda within animalia, and bacteria as a type of monera.
Bacteria, which are part of the Monera kingdom, are the most common and ancient organisms on earth. They have a close connection to the lives of all organisms. Bacteria are prokaryotic and obtain nutrition similar to fungi. They feed on dying material and convert it back into basic substances. Bacteria can also get energy through photosynthesis. Reproduction in bacteria occurs asexually through binary fission, where a copy of the DNA is made and then the membrane divides to create two identical bacteria. Like all cells, bacteria contain DNA, but bacterial DNA is arranged in circular strands instead of linear ones. Additionally, bacteria have genes on smaller rings known as plasmids.
Redwood trees in the Plantae kingdom are distinct because they utilize photosynthesis, using the sun and carbon dioxide to produce their own food. These trees also have the ability to reproduce asexually and possess both male and female parts, enabling independent reproduction without external reliance.
The redwood tree population consists of two varieties that can be differentiated by their habitat. The coast redwood is found thriving along the Pacific coast from southern Oregon to central California, boasting an estimated lifespan of 2500 years. Its leaves exhibit a bluer hue and are more needle-like compared to those of Dawn Redwood trees.
Dawn Redwoods were once dominant in North America as a sequoia tree species and were regarded as ancestors of California redwoods. When juxtaposed with coast redwoods, these trees display noticeable disparities in their branches and leaves.
Protists are a diverse group of organisms that can be found in various environments, including fresh water, seawater, soils, and animal intestines, where they play important roles in digestion. Many protists are capable of photosynthesis to produce their own food like plants. They also possess the ability to move independently like animals. Unlike multicellular organisms, protists do not have specialized tissues.
Seaweeds, amoebas, and slime molds are examples of protists. Protists typically undergo asexual cell division for reproduction. The Protista kingdom includes economically significant members such as disease-causing organisms like malaria.
It is believed that the Protista kingdom originated around 600 million years ago and led to the Plantae, Animalia, and Fungi kingdoms. In summary, members of the Protista kingdom display both plant and animal characteristics and are mainly unicellular requiring microscopic observation.
Unlike protista, Arthropoda belongs to the animalia kingdom. Arthropods are invertebrate animals characterized by their external skeleton and jointed appendages. Crustaceans, insects, and spiders are examples of Arthropoda. This phylum is the largest in the animal kingdom and comprises approximately 875,000 known species, found in almost every habitat. Early arthropods likely resembled their presumed ancestors, annelids, with long, soft bodies composed of many segments, each equipped with a pair of limbs. Over time, the body surface of arthropods hardened to form an external skeleton, providing protection but presenting challenges. To grow, arthropods must shed their exoskeletons, leaving them temporarily soft and vulnerable. The strength and other properties of an exoskeleton also decrease with size, limiting the growth potential for most arthropods. However, arthropods unsupported by water generally do not grow very large. Lobsters, for example, reach an average weight of about 44 lb. The exoskeleton of arthropods helps protect against dehydration, explaining why many arthropods thrive in desert environments. Although complicated, the nervous system of arthropods is relatively small.
Every organism is distinct and varies from one another, having to adjust to their environment by acquiring new characteristics for their own benefit. Throughout evolution, every species undergoes changes to better adapt to their respective habitats. Examples include elephants, humans, ciliophora, artichokes, and turtles.
Both elephants and humans have undergone evolutionary changes over time. Elephants, originating from woolly mammoths, gradually evolved to survive in hotter climates by reducing their hair coverage. Similarly, humans evolved from primates, resulting in a loss of hair, a decrease in jaw size, and an increase in brain size. These adaptations allowed humans to thrive in their respective environments. Additionally, humans possess limbs that enable upright walking as another adaptive feature.
In contrast, artichokes employ multiple leaves as a protective barrier for their delicate core, shielding it from potential harm. The Ciliophora organism exemplifies adaptation through the development of numerous tiny hair-like projections across its body. These projections aid movement and facilitate navigation between different locations.
A diverse ecosystem is typically stronger as all organisms depend on each other to survive and thrive, enhancing productivity. The coexistence of different species contributes to the overall health of the environment and serves as evidence of its condition. Diversity adds excitement and intrigue to life; without it, we would essentially be nothing!
