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Ch 3.1 What is Life?
The questions and vocabulary come from Ch3 sec1 of the Pearson science book
| Term | Definition |
|---|---|
| Organism | Another word for living things. |
| Cell | The basic unit of structure and function in an organism. |
| Unicellular | Single celled organisms. |
| Multicellular | Organisms composed of more than one cell/ many cells. |
| Metabolism | The combination of chemical reactions through which an organism builds up or breaks down materials. |
| Stimulus | A change in an organism's surroundings that cause an organism to react. |
| Response | How an organism reacts to a stimulus. |
| Water | The most abundant chemical in cells. It is the universal solvent. |
| Development | The process of change that occurs during an organism's life, producing a more complex organism. |
| Growth | The process of becoming larger. |
| Reproduction | To produce offspring that are similar to the parents. |
| Asexual Reproduction | Involves only one parent and produces offspring that are identical to the parent. |
| Sexual Reproduction | Involves two parents and combines their genetic material to produce a new organism that differs from both parents. |
| Spontaneous Generation | The mistaken idea that all living things can arise from nonliving sources. |
| Francesco Redi | An Italian doctor from the 1600's that helped disprove spontaneous generation. |
| Redi's Experiment | Redi designed a controlled experiment to show that maggots, which develop into new flies, do not arise from decaying meat. |
| Controlled Experiment | An experiment in which a scientist that carries out a series of tests that are identical in every aspect except for the independent variable (manipulated variable). |
| Louis Pasteur | A French Chemist from the mid-1800's, that designed an experiment with broth and bacterial growth to test spontaneous generation. His experiment helped to disprove spontaneous generation. |
| Pasteur's Experiment | Pasteur designed an experiment with broth in two curved neck flasks that were boiled to kill bacteria. Air could not enter either of the flasks. The flasks sat for a year w/o bacterial growth. On one of the flasks, the neck was broken and bacteria grew! |
| Autotrophs | Organisms that can make their own food. Example= plants |
| Heterotrophs | Organisms that obtain their energy by feeding on other organisms. Examples= humans, cows, lions, vultures |
| Homeostasis | The maintenance of stable internal conditions in an organism. |