characteristics of life
Terms in this set (5)
organisms are highly organized
All organisms are composed of one or more cells. Organisms can be unicellular (made of one cell) ex: bacteria, amoeba, paramecium) or multicellular (made of multiple cells) ex: tree, crab, horse. Cells contain specialized structures called organelles that perform specific functions within the cell.
organisms grow and develop
Growth is to increase in size. Development includes all of the changes an organism experiences in its lifetime. Ex: a butterfly's life cycle (egg, larva, pupa, butterfly)
organisms obtain and use energy
Organisms obtain energy in one of two ways. Autotrophs manufacture their own food/energy (ex: plants using photosynthesis to convert sunlight, water and oxygen into glucose/sugar) Heterotrophs must take in food/ energy, usually plant or animal matter (ex: a herd of wildebeest eating grass, a lion pride hunting and eating a wildebeest).
Through reproduction, organisms are able to replace themselves and continue the species. Reproduction can be asexual or sexual.
a. Asexual Reproduction (no partner required)
Organisms produced asexually are virtually identical copies, or clones, of a single parent. (ex: bacteria, amoeba)
b. Sexual Reproduction (a partner is required)
Sexual reproduction involves two parents, and each parent contributes half of the genetic material. (ex: most animals)
organisms adapt to changes in their environment
Organisms are able to recognize changes in their internal and external environments, and they can respond to these changes.
ex: plants can detect light from the Sun and respond to this stimulus by bending toward the light.
ex: when a person is too hot, he sweats, and heat is removed as the sweat evaporates.
(When an organism adapts to its internal environment, as in sweating, it is trying to achieve an internal balance, or what is called homeostasis.)