Classification of Living Things Notes
1.
An organism is a living thing.
2.
Characteristics of all living things:
1) Organisms obtain and use resources. All organisms must obtain resources, such as food and water, which provide required energy to perform the basic processes of life, like growing, developing, and repairing injured parts.
2) Organisms respond to stimuli: A stimulus is any change in an organism’s surroundings that will cause the organism to react. Examples of environmental stimuli include changes in the amount of light present, changes in temperature, sound, amount of water, space, amounts of food present. The reaction to the stimulus is called a response. It can be an action or behavior performed by the organism.
3) Organisms reproduce-produce offspring that have similar characteristics as the parents. Reproduction can occur in one of two ways: a) Asexual reproduction involves one parent that makes an exact copy of itself. The offspring are identical to the parent. b) Sexual reproduction involves two parents. Sperm cell from the male and egg cell from the female combine to produce offspring that have characteristics from each parent.
4) Organisms grow and develop. Growth is the process of an organism becoming larger. Development is the process that occurs during the life of an organism that results in the organism becoming more complex.
Organisms require energy to grow and develop.
3.
Classification is the process that scientist use to arrange organisms into groups based on the shared observable characteristics.
4.
Taxonomy is the science of identifying and classifying organisms into groups.
5.
A taxonomist is a scientist who identifies and names organisms based on their similarities and differences.
6.
Taxonomist use physical characteristics as well as DNA, genetic information, to classify organisms.
7.
Scientist all over the world study organisms, in order to avoid confusion scientists need a universal way of naming organisms.
8.
A dichotomous key is a tool used to identify organisms. It uses a series of questions, each with only 2 answers.
9.
Linnaeus developed a system for classifying organisms called binomial
nomenclature. It uses two Latin words to name an organism. The name is made up of the genus and species of the organism. The name is written in

italics, the genus is capitalized, and the species is lower case; for example, the scientific name for a human is
.
10.
The Linnaeus system is made up of seven levels, Kingdom, Phylum, Class, Order,
Family, Genus, and Species.
1) King Philip Could Only Find Green Socks is one mnemonic way to remember the order of the levels. Another is King Philip Came Over For
Good Spaghetti.
2) The levels are arranged from the most broad, Kingdom, to the most specific, Species.
11.
Kingdom- organisms are placed into kingdoms based on their ability to make food and the number of cells in their body.
12.
Phylum (phyla is plural)- In the Plant Kingdom, phyla are sometimes called divisions. In the Animal Kingdom, there are 35 different phyla.
13.
Class, Order, Family-these levels become even more specific. Each level has fewer organisms that have more in common with each other as you move down the levels.
14.
Genus- contains closely related organisms. The genus is the first word in an organism’s scientific name.
15.
Species- consists of all the organisms of the same type which are able to breed and produce young of the same kind. The species is the second word in an organism’s scientific name.
16.
Most scientists classify organisms into 5 kingdoms: Plants, Animals, Protists,
Fungi, and Monera.
1) Plants (Plantae)- the plant kingdom is made up of plants. Plants are
autotrophs, they make their own food. Plants are eukaryotes; they are made up of many cells. Plants are divided into 2 groups: vascular and nonvascular.
2) Animals (Animalia)- the animal kingdom is made up of animals.
Animals are heterotrophs- they must obtain food by eating it. Animals are eukaryotes. The 35 phyla are divided into two groups: vertebrates and invertebrates.
3) Fungi- the fungi kingdom is made up of molds, yeasts, and mushrooms.
Fungi are heterotrophs because they must absorb their food. Yeasts are one celled, while molds and yeasts are eukaryotes. Their cells have a nucleus, a cell wall, and no chlorophyll. Most fungi are decomposers, they break down dead organisms.
4) Protists (Protista)- the protists are made up of organisms that cannot easily fit into the plant, animal, or fungi kingdoms. They are one celled organisms with a nucleus or simple multicelled organisms. Some protists are autotrophs, some are heterotrophs.
5) Monera- the Monera kingdom is made up of bacteria. Their cells do not contain a nucleus. Some bacteria are autotrophs, some are heterotrophs.