Level-1 K-W-L: Living things Under the “K” portion of the handout write 2 sentences about living things. Always write in complete sentences.

Level-1 Date and title your notebook entry Title – “Check Yourself” Write the entire problem in your notebook after the title to include all four choices and then circle the correct choice. In unicellular organisms, growth is due to an increase in the ______ of the cell. Size Surroundings Sun Number

ACOS 1 Objectives: Students will be able to identify characteristics that all living things share. Students will be able to discuss the concept of biogenesis. Students will be able to list the things all living things need to survive.

Living Things What does it mean to be alive? An organism is any living thing. In spite of differences, all organisms have similar traits.

5 Characteristics of Life Made of cells Respond to stimuli Use energy Grow & develop Reproduce

Cellular organization A cell is the smallest unit of an organism that carries on the functions of life.

Cellular organization Unicellular means only one cell Multicellular means composed of many cells.

Respond to Stimuli Living things interact with their surroundings. A stimulus is anything that causes change in an organism. A response is the reaction to a stimulus.

Use Energy The energy used by most organisms comes either directly or indirectly from the Sun. Plants and some other organisms use the Sun’s energy and the raw materials carbon dioxide and water to make food.

Grow & Develop In unicellular organisms, growth is due to an increase in the size of the cell. Growth of multicellular organisms is mostly due to an increase in the number of cells.

Reproduce Cats, dogs, alligators, fish, birds, bees, and trees eventually reproduce. All living things reproduce. Without reproduction, living things would not exist to replace those individuals that die.

Water Water is important for all living things. Plants and animals take in and give off large amounts of water each day. Most organisms are composed of more than 50 percent water. Humans are made of 60 to 70 percent water.

Heterotrophs Living things are made up of substance such as proteins, fats, and sugars which is their source of energy. Heterotrophs are organisms that cannot make their own food. Heterotrophs must obtain energy by feeding on others. Examples of heterotrophs are lions and humans.

Autotrophs Autotrophs are organisms that can make their own food. Autotrophs use the food they make for energy. Examples of autotrophs are plants.

Limitations The environment limits where organisms can live. Not many kinds of organisms can live in extremely hot or extremely cold environments. Most cannot live at the bottom of the ocean or on the tops of mountains. An organism’s surroundings must provide for all of its needs.

Homeostasis Organisms must be able to keep the conditions inside their bodies stable, even when conditions in their surroundings change significantly. For example body temperature. Homeostasis is the maintenance of stable internal conditions.

Spontaneous generation Before the seventeenth century, some people thought that insects and fish came from mud, that earthworms fell from the sky when it rained, and that mice came from grain. Spontaneous generation is the idea that living things come from nonliving things. This idea became a theory that was accepted for several hundred years.

Biogenesis It was not until the mid 1800s that the work of Louis Pasteur provided enough evidence to disprove the theory of spontaneous generation. It was replaced with biogenesis which is the theory that living things come only from other living things.