Characteristics of Living Things
PRESENTATION OUTLINECHARACTERISTICS OF LIVING THINGS CELLULAR ORGANIZATION A cell is the basic building block of life. The cell is the basic unit of structure and function of all living things. Organisms may be made up of one cell or many cells. SINGLE CELL ORGANISMS Some organisms, like bacteria, are made up of only a single cell. These organisms are unicellular organisms. This single cell carries out all functions necessary for life. MULTICELLULAR ORGANISMS Organisms that are made up of many cells are called multicellular. Humans are made up of trillions of cells. Cells may be specialized to carry out certain functions. Specialized cells work together to keep an organism alive. GROWTH AND DEVELOPMENT All living things grow and develop. Development is a process of change where an organism becomes more complex. During development, cells may change from one type to another. A cell may become specialized for a particular purpose. GROWTH Growth involves cells growing and multiplying. Cells are only able to grow to a certain size. For and organism to grow, the number of cells has to increase. ENERGY USE Organisms get energy from taking in and breaking down food sources. The chemicals reactions through which an organism breaks down materials to get energy, and then uses energy to build materials back up again is called metabolism. ENERGY USE An organism uses energy for all of its life processes It uses energy for growth and development It uses energy for repairs of injured or broken parts It uses energy for every day functions, like movement RESPONSE TO SURROUNDINGS All living things respond to changes in their environment. A change in the environment that causes the organism to react is called a stimulus. A stimulus might be a change in light, sound, temperature, or other factors. RESPONSE An organism reacts to a stimulus with a response. A response is an action or a change in behavior. For example, have you ever jumped when you heard a loud noise? Maybe a really loud clap of thunder? That's a response! REPRODUCTION A characteristic of living things is the ability to reproduce. Organisms may reproduce in different ways. Asexual reproduction involves only one parent, and produces offspring that are identical to the parents. SEXUAL REPRODUCTION Sexual reproduction involves two parents and combines their genetic material. This type of reproduction produces an offspring that is genetically different from both parents. Mammals, birds, and most plants sexually reproduce. CHEMICALS OF LIFE The cells of living things are made up of chemical molecules The most abundant molecule is water. Two other chemical molecules, proteins and lipids, are building materials of cells. The chemicals called carbohydrates are a cell's main source of energy. Nucleic acids are the genetic material of the cell, and are found in the nucleus. Haiku Deck Pro User