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Characteristics of Life. 1. All Life is Made of Cells. Cells are very small, very organized and covered by a membrane. Cells are the smallest unit of life. 2. All living things reproduce. 3. Metabolism. What do scientists mean by metabolism?.
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Cells are very small, very organized and covered by a membrane Cells are the smallest unit of life.
What do scientists mean by metabolism? • Metabolism is the sum of all chemical reactions carried out in an organism • Living organisms carry out reactions to obtain and use energy.
What is homeostasis? • Homeostasis is the ability to maintain stable internal conditions. What are some examples of this ability in humans?
Examples of Homeostasis • In humans: • Shivering, sweating, feeling thirst or hunger • Other animals that live in the cold have fur or a layer of fat to keep warm • Bacteria that live in toxic environments like high acid lakes can neutralize the acid in their cells
All living things pass on traits to their offspring • The passing of traits from parents to offspring is called heredity • A gene is a short section of DNA • A gene is the basic unit of heredity • A mutation is a change in the DNA of a gene
Evolution occurs in populations not individuals • Evolution is a change in the inherited characters of a species over time. • Natural Selection – the process in which organisms with the most favorable traits are more likely to survive and reproduce
All life depends on other living things • All living things are connected • Ecology is the branch of biology that studies the interactions of organisms with each other and with the nonliving part of their environment.