CHARACTERISTICS OF LIVING THINGS

LIVING THINGS HAVE CELLS Cell: a membrane-covered structure that contains all of the materials necessary for life. Too small to be seen w/naked eye. Multicellular---organisms made of many cells Unicellular---organisms made of only one cell---different parts of cell perform different functions.

LIVING THINGS SENSE & RESPOND TO CHANGE Stimulus: a change that affects the activity of an organism. Response: How an organisms reacts to a change Example: Eye is exposed to light (stimulus) and the pupils become smaller (response). Homeostasis: Maintenance of a stable internal environment. Outside environment may change; inside stays the same.

LIVING THINGS SENSE & RESPOND TO CHANGE (continued) Responding to external changes….. Body maintains an internal temperature. Hot—body sweats! Cold—muscles twitch to warm you! (aka, “shivering”) Other animals have to control their body temp by moving from one environment to another.

LIVING THINGS REPRODUCE Sexual reproduction: 2 parents produce offspring that share characteristics of both parents. Offspring do not look exactly like parents. Most animals/plants reproduce this way. Asexual reproduction: single parent produces offspring that are identical to the parent. Most single-celled organisms reproduce this way. (Ex: hydra—forms buds that break off and grow into new individuals.)

LIVING THINGS HAVE DNA Deoxyribonucleic acid (DNA) Controls structure & function of cells Organisms reproduce—pass off copies of their DNA to their offspring Heredity: passing of traits from one generation to the next.

LIVING THINGS USE ENERGY Living organisms need energy to grow, develop, repair damage, and reproduce Metabolism: total of all of the chemical activities that an organism performs.

Growth means to get bigger in size  All Living Things Grow Growth means to get bigger in size

All Living Things Develop  All Living Things Develop Development involves a change in the physical form or physiological make-up of an organism

All Living Things Adapt to Their  All Living Things Adapt to Their Environment Through Evolution Adaptation A process that enables organisms to become better suited to their environment Species obtain adaptations through evolution over great periods of time

An Example of Adaptation Desert plants have succulent waxy leaves and stems to store water and reduce water loss