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What is Life? Cell Theory. What is Life?. What is Life? Where do living things come from? What characteristics do living things share? ?. Characteristics of living things. Living things are made of cells. Living things obtain and use energy. Living things grow and develop.
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What is Life? • What is Life? • Where do living things come from? • What characteristics do living things share? ?
Characteristics of living things • Living things are made of cells. • Living things obtain and use energy. • Living things grow and develop. • Living things reproduce. • Living things respond to their environment. • Living things adapt to their environment.
Characteristics of living things • Living things are made of cells. • The smallest part of an organism is a cell. Some organisms are unicellular while others are multicellular.
…Characteristics of living things • Living things obtain and use energy. • Some organisms like plants, algae, and some microrganisms are autotrophs. Autotrophs use photosynthesis to make their own "food." Some bacteria use chemosynthesis for their energy source. • Animals and fungi are heterotrophs and capture their food in a variety of ways. The food must be converted to a usable form of energy, ATP. ATP is a chemical our cells can use through metabolism
…Characteristics of living things • Living things grow and develop.
…Characteristics of living things • Living things reproduce. • What would happen if organisms couldn’t reproduce? • Organisms either reproduce sexually or asexually.
…Characteristics of living things • Living things respond to their environment. • This often results in movement of the individual toward safety. This helps to ensure survival of the organism. For example, as young children we learned to avoid hot stoves and busy streets. • Plants also have some limited ability to move. They grow up toward the sun, and some have leaves able to turn to follow the sun, allowing them to photosynthesize better. Their roots grow down to search for water and minerals. If a plant doesn't get enough sunlight, water or minerals it will die.
…Characteristics of living things • Living things adapt to their environment. • Modifications enable an organism to survive in its environment. Natural selection allows individuals with better adaptations to survive better and reproduce more. Thus, their characteristics are passed into future generations and that makes the species stronger.
Biogenesis vs. Abiogenesis • Abiogenesis: “Life from Non-life” • A.K.A. Spontaneous Generation. Living things come from non-living matter. • There are many silly beliefs that were once commonplace: • maggots came from rotting meat • mice could be produced from a pile of old rags and bran • fish come from rotting leaves. • lice come from sweat • eels come from sea mud • People believed in Spontaneous Generation as late as the 1600’s. • Biogenesis: life from life • Biogenesis is the idea that life can only come from life. This is one of the main postulates of the cell theory. It assumes that cells can only come from pre-existing cells. • Where did the first cells come from, then?
Clapping Bear • Watch the Talking Dog perform and answer the following; • Describe the ways the dog looked ‘alive’. • What characteristics of living things are NOT shown by the Talking Dog ?
