Genetically Distinct Group Of Organisms Essay Example

of classification, we have species. The sequence of categories, from broadest to most specific, is kingdom, phylum, class, order, family, genus, and species. Each level serves to group organisms that share a greater number of characteristics with one another.

Biologists use Binomial Nomenclature to assign a two-word scientific name to each organism. This naming system ensures accurate communication of information and is also referred to as the "binomial" system in biology, as it uses two names (genus and species) to identify every organism.

The binomial system employs a Latin name consisting of two words. In the case of humans, the binomial name is Homo sapiens. The word Homo indicates the genus while sapiens indicates the species. Likewise, the red maple tree has a binomial name Acer rubrum.

The Latin name for maple, Acer, refers to the genus, while the Latin name for red, Rubrum, refers to the species. The genus name represents a specific group of organisms and is capitalized, while the species name provides a Latin description of a significant characteristic of the organism and is not capitalized. This classification system was designed to prevent confusion within scientists by avoiding common names.

Human beings are scientifically referred to as Homo sapiens. Our species is represented by the genus "Homo", while "sapiens" signifies our species. Fossils of other members of our genus, such as Homo erectus and Homo habilis, have been discovered. These fossils bear similarities to us but differ enough to be classified as a distinct species. In terms of taxonomy, the Homo genus belongs to the Hominidae family. This family is part of the Primates order, which also includes chimpanzees, gorillas, and monkeys.

Mammals belonging to the class

Mammalia are called primates and are part of the phylum Chordata. Chordata includes creatures with spinal cords and falls under the kingdom Animalia, which is the highest level of classification. These classifications help determine how closely related different organisms are. For example, animals in the same family and genus have a closer relationship than those in just the same family. The classification system organizes organisms based on shared characteristics, helping biologists group them accordingly.

This organization assists biologists in the study of living organisms by aiding in the analysis of relationships and making predictions. The analysis involves considering various characteristics, including structural, biochemical, cytological, embryological, behavioral, and fossil information. Modern taxonomists may consider all these characteristics when classifying an organism into a Taxonomic Category. Whittaker's classification system identifies five kingdoms: monera (bacteria and blue-green algae), protista, fungi, plantae, and animalia.

Bacteria are unicellular prokaryotes without membrane-bound organelles like a nucleus. This sets them apart from eukaryotic organisms such as plants and animals that possess a nucleus. Bacteria belong to their own unique kingdom called monera. They can be autotrophs or heterotrophs and include disease-causing strains.

There are various methods for classifying bacteria, including their energy production, shape, and staining properties. Bacteria can be classified based on their physical form and shape. For instance, cocci refer to spherical shaped bacteria, bacilli denote rod-shaped bacteria, spirillum represents spiral shaped bacteria, and vibrio signifies comma shaped bacteria. Despite being unicellular, bacteria can sometimes be found in clusters or chains rather than as individual cells. The identification and naming of bacteria depend on their shapes and the way they appear in groups.

Microbiology scientists categorize bacteria based on their oxygen needs. Bacteria that

depend on oxygen are aerobic, while those that don't require oxygen are anaerobic. Aerobic bacteria utilize glucose and nitrates for energy via oxidation, whereas anaerobic bacteria use methane for energy and oxidize sulfur molecules and hydrocarbons.

Bacteria are capable of surviving in low oxygen environments like mud and their classification is based on staining properties. The gram-staining technique, developed by Danish physician Christian Gram in 1884, is still widely used by microbiologists today. This method involves applying bacteria samples onto slides, staining them with violet dye, and treating them with iodine.

The slide should be washed with alcohol and then stained with safranine, a pink dye. The violet stain has a weak binding to the cell walls of gram-negative bacteria, which can be washed out by alcohol. However, after being counterstained with safranine, gram-negative bacteria will appear as pink to red. On the other hand, gram-positive cell walls have a strong affinity for the violet stain and will keep it even after being rinsed with alcohol.

Upon completion of the process, the cells experience a color transformation from dark purple to brown. The differentiation among these cell types appears to be linked to the amount of peptidoglycan found in their cell walls. In the past, bacteria were classified based on their shape and staining properties. While these characteristics still hold value for initial identification purposes, advancements in DNA and RNA sequencing have enabled a more accurate comprehension of their ancestry and relationships, thereby assisting in classification. The second group is known as kingdom protista and comprises eukaryotic organisms.

They include primarily unicellular eukaryotes, but there are also a few examples of multicellular ones. Eukaryotic cells have membranes surrounding their

nuclei and organelles. The DNA of eukaryotes is housed within a nucleus that is bounded by a membrane. The cells of multicellular protists do not have specialized functions within the organism. Protists encompass organisms like Euglena, Amoebas, and Plasmodia. Some protists hunt for food similar to animals, while others are capable of photosynthesis to produce their own food from sunlight, akin to plants.

Protists are categorized based on their method of movement, which typically involves flagella, cilia, or pseudopodia. For instance, Euglena utilizes flagella for movement, rotating as it moves. Paramecium possesses numerous hair-like cilia that it beats in a synchronized manner. Lastly, amoeba moves by extending pseudopodia.

Pseudopodia require a surface, such as submerged rocks, to move an amoeba. Moving on to the third kingdom, fungi are also eukaryotes. While most fungi are multicellular, there are also unicellular fungi like yeast. Cells of fungi have cell walls containing chitin. Fungi are heterotrophs.

Fungi are similar to plants in some ways, but they differ because they lack a cellulose cell wall and chloroplasts with chlorophyll. This difference prevents them from being classified as plants. Unlike plants, fungi obtain nutrients by secreting digestive enzymes into their food source and then absorbing the digested food. Fungi can act as decomposers or parasites. Examples of fungi include mushrooms, toadstools, molds, and yeast. The classification of fungi is determined by whether they are saprophytic or parasitic.

A saprophyte is an organism that obtains nourishment by feeding on dead or decaying organic matter. Conversely, a parasite acquires nourishment from another animal or plant referred to as a host. Unlike saprophytes, parasites do not offer any advantage to the host and can even result

in its demise if they reside within it for a prolonged duration and exhaust its nourishment. Hence, fungi that consume dead or decaying matter are categorized as saprophytic fungi.

Examples of saprophytic fungi, such as bird's nest and toadstools, obtain their nourishment from decomposing organic matter. In contrast, parasitic fungi, like the potato blight, acquire their nourishment from living organisms. Fungi are classified based on their sporangium fruiting body and can also be categorized according to their reproductive method which involves spore formation and the subsequent dispersal of these spores.

Fungi possess the capacity to reproduce through both asexual and sexual means, producing spores resembling seeds. These spores can be dispersed by wind or rain, enabling the fungus to extend its range. Some species have the ability to reproduce in either manner depending on their environment. Mushrooms release spores for reproduction, while yeast undergo asexual reproduction via binary fission. Furthermore, there exists a distinct kingdom referred to as the plant kingdom, comprising multicellular eukaryotic organisms.

Phototrophs, organisms that use photosynthesis to produce energy, depend on chloroplasts within plant cells. These chloroplasts contain chlorophyll, the crucial pigment. Additionally, plant cells are characterized by cellulose cell walls.

Plants have specialized cells for various functions such as photosynthesis, material transport, and support. The plantae kingdom includes different types like mosses, liverworts, ferns, gymnosperms (conifers), and angiosperms (flowering plants). Plants can be categorized based on their type like angiosperms, mosses, or other varieties. They can be found in various forms and habitats – on land or in water. Plant sizes vary greatly; from small moss plants to tall giant sequoias.

Mosses and liverworts, also known as bryophytes, are discovered in moist and shaded

regions. These plants possess basic transport mechanisms and rely on rhizoids, root-like structures, for anchorage. Unlike plants with true roots, stems, and transport systems, mosses and liverworts lack efficient water conduction due to the absence of vascular tissue. Consequently, their limited size is attributed to this deficiency in transportation. Instead, nutrients and water diffuse between cells.

Ferns are vascular plants and possess a basic transport system, along with simple stems and roots. Similar to moss, ferns also serve as spore producers and primarily reproduce asexually through spore dispersion. In contrast to ferns, conifers have a protective cuticle coating their needle-shaped leaves, unlike the absence of cuticles in ferns. Consequently, ferns are prone to excessive water loss and dehydration, just like mosses, which restricts their growth in areas exposed to direct sunlight.

Conifers are able to grow in harsh environments due to their cuticle and the reduced surface area of their needle-like leaves, making them less prone to dehydration. They reproduce sexually through cones and rely on wind pollination. Angiosperms are considered the most successful form of plant life on earth.

Angiosperms are found in various habitats, ranging from the hot, dry desert to the arctic Tundra. They outnumber all other plant groups in terms of species. Compared to other plants, angiosperms possess a more intricate transport system. They have well-developed root, stem, and leaf structures that feature vascular tissues for water and food conduction. Additionally, they possess a protective waxy cuticle coated with cutin and stomata that can close to minimize water loss. The reproductive process of angiosperms is sexual in nature.

Angiosperms are the plants that produce seeds surrounded by a fruit, using animals for both pollen spread

and seed dispersal. These mechanisms allow for highly efficient seed dispersal. The final kingdom is the animal kingdom, consisting of multicellular eukaryotic organisms that cannot photosynthesize.

Animals are heterotrophs, meaning they depend on plants or other animals for energy. Unlike plant cells, animal cells do not have cell walls or chloroplasts. Most animals have specialized systems for support, locomotion, digestion, excretion, nervous functions, endocrine regulation, respiration, circulation, and reproduction. While most animal species can move between locations, exceptions such as sponges and barnacles permanently attach to surfaces. Animals are classified based on different criteria.

Animals can be divided into two main categories: vertebrates and invertebrates. Vertebrates, which have a backbone, are distinct from invertebrates, which lack both a backbone and a nervous system. Examples of invertebrates include sponges, jellyfish, annelids (such as earthworms), mollusks (including clams, oysters, and slugs), and arthropods.

Sponges are considered the most fundamental type of animal. Annelids are represented by earthworms, while mollusks encompass clams, oysters, and slugs. Mollusks often possess a hard shell.

The arthropods, which include insects, crustaceans (such as crabs and lobsters), and arachnids (such as spiders), are the most advanced invertebrates. They possess a tough exoskeleton. Invertebrates are classified based on factors like body symmetry (radial or bilateral), body segmentation, cephalization (the concentration of crucial nerves at the head or end of an animal), and gut type.

The vertebrates, including fish, amphibians, reptiles, birds, and mammals, have a backbone, a nervous system, a heart, and a closed circulation system. Mammals, such as humans, are the most advanced forms of animals. They have characteristics like fur, sweat glands, and mammary glands. The average body temperature of mammals is 37 degrees Celsius. Although there

are exceptions like the duck-billed platypus, most mammals give birth to their young instead of laying eggs.

Animals can be classified based on their reproduction method. Fish, for example, have scales, no limbs, and move by swimming. Additionally, they reproduce by laying eggs.

Amphibians, which can dwell in both water and land, cannot stray too far from bodies of water like ponds and lakes. It is necessary for them to lay their eggs in the water. Conclusively, reptiles, similar to amphibians, possess scales and also lay eggs.

Birds do not reproduce by giving birth to their offspring, but rather lay eggs. They possess feathers, wings, and have the ability to fly. In addition, they maintain a body temperature of about 42 degrees Celsius.

Birds lay eggs because their metabolism needs to work extremely fast in order for them to fly.