Characteristics of Living Organisms
Characteristics of Living Organisms
Movement
- All living organisms show some form of movement. This may be in the form of relocation from one place to another, or simply internal movement as part of physical functions.
Sensitivity
- Sensitivity refers to an organism’s response to changes in their environment. This could involve responding to changes in temperature, light intensity, or prey in the vicinity.
Growth
- Living things demonstrate growth, which involves an increase in size, complexity, and the number of cells.
Reproduction
- Reproduction is a vital characteristic of living organisms to ensure the continuation of the species. This can take the form of sexual reproduction (involving two parents and the combination of their genes) or asexual reproduction (involving a single parent and no combination of genes).
Excretion
- All living organisms perform excretion, the process of removing waste products from their bodies. This could include carbon dioxide expelled during respiration, or urea excreted by animals as a waste product from the breakdown of proteins.
Nutrition
- Nutrition is the process by which organisms obtain energy and the raw materials needed for growth, repair and reproduction. Plants obtain their nutrition through photosynthesis, while animals consume other organisms.
Respiration
- Respiration is the process by which organisms extract energy stored in food. This is fundamental to all forms of life. Oxygen from the environment reacts with glucose in the cells to produce energy in a process known as aerobic respiration.
Classification of Organisms
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One method of classifying organisms is the binomial system of nomenclature, with all organisms bearing a two-part Latin name. The first part is the Genus (always capitalised) and the second is the species (not capitalised). Names are italicised in print and underlined when handwritten.
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The largest grouping in the classification system is the Kingdom. There are five kingdoms: Prokaryotae (bacteria), Protoctista (algae and protozoans), Fungi, Plantae (plants), and Animalia (animals).
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Each Kingdom is divided into Phyla (singular: Phylum), each Phylum is divided into Classes, each Class into Orders, each Order into Families, each Family into Genera (singular: Genus), and each Genus into Species.
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Species is the most basic unit in this system. Members of the same species can interbreed to produce fertile offspring.