Characteristics of Life PDF

Characteristics of Life Section 1.3 Living Things For an organism (living thing) to be considered alive, it must satisfy all 8 characteristics of life. 1. Made of Cells 2. Reproduce 3. Based on a Genetic Code 4. Growth and Development 5. Need for Materials and Energy 6. Res...

Characteristics of Life Section 1.3 Living Things For an organism (living thing) to be considered alive, it must satisfy all 8 characteristics of life. 1. Made of Cells 2. Reproduce 3. Based on a Genetic Code 4. Growth and Development 5. Need for Materials and Energy 6. Response to Environment 7. Maintaining Internal Balance 8. Evolution 1. Made of Cells Unicellular - made of one cell Multicellular - made of two or more cells 2. Reproduction Reproduction - the creation of offspring/babies Reproduction is NOT essential for the survival of an individual organism but is essential for the survival of the species. 3. Based on Genetic Code Offspring usually resembles their parents. Sexual Reproduction - requires two cells (sperm and egg). Generally similar to parent Asexual Reproduction- requires only one cell - a single organism can reproduce without the aid of another. Generally exactly like parents. 4. Growth and Development Growth - results in an increase in the amount of material and formation of new structures Development - all changes that take place during the life of an organism 5. Need for Materials and Energy The combination of chemical reactions through which an organism builds up or breaks down materials as it carries out its life processes is called metabolism. Autotroph - gain energy from the sun Heterotroph - gain energy through food Question What is an example of an Autotroph AND a Heterotroph? Answer What is an example of an Autotroph AND a Heterotroph? Autotroph can make its own food/energy from sunlight, while a Heterotroph must eat food for energy, such as it must eat an autotroph or a heterotroph. 6. Response to the Environment Organisms detect and respond to stimuli (a signal) from their environment. Internal Stimuli - comes from within the organism – Level of blood sugar External Stimuli - comes from outside the organism – Shivering when it's cold outside 7. Maintaining Internal Balance Homeostasis - internal regulation to maintain suitable conditions for life Question Why is homeostasis so important? Answer Why is homeostasis so important? If we don’t keep ourselves in balance, we can get sick or even worse. All organisms work to ensure homeostasis is happening at all times. 8. Evolution Although individual organisms experience many changes during their lives, the basic traits they inherited from their parents usually do not change. As a group, however, any given kind of organism can evolve, or change over time. Depending on the species’ generation lengths, this will only be seen over hundreds of thousands or even millions of years for the change to be dramatic enough to see a difference. Branches of Biology Some of the levels at which life can be studied include molecules, cells, organisms, populations of a single kind of organism, communities of different organisms in an area, and the biosphere. At all these levels, smaller living systems are found within larger systems. Three Domain System Bacteria - are unicellular and prokaryotic. Archaea - unicellular and prokaryotic, and live in some of the most extreme environments. Eukarya - multicellular and eukaryotic Question Why are viruses not considered living? Answer Why are viruses not considered living? It does not follow all the proper characteristics of life, especially the portion of reproduction. All viruses require an external source in order to reproduce. Likewise, they do not grow. They can mutate, which is different than growth (we will discuss mutations later this year).  Levels of Organization The part of Earth that Biosphere contains all ecosystems A group of ecosystems that Biome have the same climate and similar dominate communities Community and its nonliving Ecosystem surroundings Populations that live together Community in a defined area  Levels of Organization Continued Group of Organisms of one type Population that live in the same area Organism Individual living thing Groups of Tissues, organs, and organ Cells systems Cell Smallest functional unit of life Group of atoms; smallest unit of Molecule most chemical compounds