CHARACTERISTICS OF LIVING THINGS What characteristics are observed to determine if something is “alive”?

All living things are organized. The cell is the basic unit of organization. The cell is the basic unit of organization. Organelles → cells → tissues → organs → Organelles → cells → tissues → organs → organ systems → organism organ systems → organism

Organization Continued Species→Population→Community→Ecosystem→Biome→ Biosphere Species→Population→Community→Ecosystem→Biome→ Biosphere Species – group of similar organisms that can interbreed and produce fertile offspring Species – group of similar organisms that can interbreed and produce fertile offspring Population – same species in same area sharing same resources Population – same species in same area sharing same resources Community – different populations in same area sharing same resources Community – different populations in same area sharing same resources Ecosystem – Community plus environment Ecosystem – Community plus environment Biome – ecosystems with same climax community Biome – ecosystems with same climax community Biosphere – layer of Earth that supports life (air, land, and water) Biosphere – layer of Earth that supports life (air, land, and water)

All living things reproduce Reproduction is not necessary for survival of an individual, but is essential for continuation of a species. Reproduction is not necessary for survival of an individual, but is essential for continuation of a species. The 2 main types of reproduction are sexual and asexual. The 2 main types of reproduction are sexual and asexual. Sexual – two parent organisms combine genetic material to produce the offspring. Sexual – two parent organisms combine genetic material to produce the offspring.

Continued: Asexual – a single organism can divide or “bud” to create offspring which are identical clones to the parent (identical genetic information). Asexual – a single organism can divide or “bud” to create offspring which are identical clones to the parent (identical genetic information).

Living things grow and develop. Growth refers to an increase in size and formation of new structures. Growth refers to an increase in size and formation of new structures. Development refers to changes during the lifetime of an organism (including cell differentiation, organ development, and aging & death). Development refers to changes during the lifetime of an organism (including cell differentiation, organ development, and aging & death).

Cell Differentiation Cell differentiation allows different cells to perform different functions for the organism; it allows for specialization. Cell differentiation allows different cells to perform different functions for the organism; it allows for specialization. Examples: Examples: Nerve cells (neurons) Nerve cells (neurons) Bone cells (osteocytes) Bone cells (osteocytes) Muscle cells Muscle cells Blood cells Blood cells

Living things respond to their environment. Living things respond or react to their environment in some way. Living things respond or react to their environment in some way. A stimulus is any condition in an environment that requires an organism to respond. A stimulus is any condition in an environment that requires an organism to respond. A stimulus can be internal or external. A stimulus can be internal or external.

Living things maintain homeostasis. Homeostasis is the regulation of a stable internal environment so life can continue. Homeostasis is the regulation of a stable internal environment so life can continue. Examples include shivering when cold or sweating when hot. Examples include shivering when cold or sweating when hot.

Living things obtain and use energy. Energy is used for growth, development, and reproduction. Energy is used for growth, development, and reproduction. Metabolism is the sum of all the chemical reactions through which an organism carries out its life processes. Metabolism is the sum of all the chemical reactions through which an organism carries out its life processes.

Living things adapt and evolve. Adaptation – any structure, behavior, or process that enables an organism to better survive in its environment. Adaptation – any structure, behavior, or process that enables an organism to better survive in its environment. Evolution – the gradual accumulation of adaptations over a long period of time Evolution – the gradual accumulation of adaptations over a long period of time