Characteristics of Living Things Living or non living, that is the question. Characteristics of Life Introduction

Living or nonliving?

Living or Non-living? People once believed that non living things such as meat, mountains, rivers, and forests were living. This thought was disproved in the 1600’s by the work of a scientist named Francisco Redi. Raw meat experiment (pg. 36)

Redi Experiment Redi knew that life could not come from non living things (spontaneous generation). People thought maggots came from meat (non-living) and not flies (living). Redi put out 2 jars of raw meat, one covered and one not covered. He found that the jar that was covered did not have maggots. The jar that was not covered had maggots.

What makes something alive? It is made of cell(s) It contains similar chemicals It obtains and uses energy It grows and develops It reproduces It responds to its surroundings

Made of cells All organisms (living things) are made of cells. A cell is the basic unit of STRUCTURE and FUNCTION in an organism. Unicellular- having only one cell Multicellular-having many cells Made of Cells Video

Chemicals of life- Similar chemicals All organisms are made of similar chemicals. Water (most abundant) Carbohydrates (cell’s energy source) Proteins & Lipids (what cells are made out of) Nucleic acid (DNA made of) Carbon (recycled through all living things)

Use energy All living things obtain and use energy. Energy is needed to do everyday things, such as eat, walk, grow, and develop.

Growth and development All organisms grow and develop. Development is the process of change that occurs during the organism’s life. You are developing. Many of you are in a growth spurt.

Reproduce All organisms reproduce. Trees drop seeds. Dogs have puppies. Organisms have to reproduce in order to keep on living. If organisms did not reproduce, their species would die off.

Respond to surroundings All living things respond to their surroundings. Stimuli- (could include) temperature, light, sound Heat Response- (action) organisms react to the stimuli. Sweat, dehydration, thirst Example- The temperature outside is 107⁰F. What happens when you are outside in the heat for several hours? Plants following the sun clip

Homeostasis The balance of the internal systems of living things. Examples: Heart Rate (resting vs. exercising) Breathing Rate (resting vs. exercising) Temperature (sweating, shivering) Fluid Level (thirst and urination amount/color) Can you think of any others? Homeostasis and Body Temperature