1-Organization of life_ 2023-20241 2.pdf

Organization of Life  Objectives The student will be able to : Define Biology. List the basic characteristics of living organisms. Identify levels of organization.  Biology Biology is the science of studying living organisms  Chara...

Organization of Life  Objectives The student will be able to : Define Biology. List the basic characteristics of living organisms. Identify levels of organization.  Biology Biology is the science of studying living organisms  Characteristics of all living things All living things share basic properties which are: 1. Cellular Organization 2. Movement 3. Growth 4. Response to stimulus 5. Homeostasis 6. Reproduction 7. Obtaining and Using Energy (metabolism) 8. Adaptation  Characteristics of all living things 1- Cellular Organization Living things are organized as they are made up of cells which is the basic unit of life that can perform all process of life. Living things are divided into:  Unicellular organisms: composed of a single cell e.g., bacteria.  Multicellular organisms: composed of many cells e.g., humans. 2. Movement Every organism is capable of some types of movement. Animals and human's movement can be clearly observed. The movement of plants is by growing and is very difficult to observe, because its movement is very slow and doesn’t cause any displacement.  Characteristics of all living things 3- Growth Living things grow and develop. For multicellular organisms, they grow by multiplying the number of the cell. For unicellular organisms, they grow by increasing the size of the cell. 4. Response to stimulus It is the ability of living organism to respond to stimulus in the surrounding environment. For example, living things respond to changes in light, heat, sound, chemical and mechanical contact. To detect stimuli, organisms have means for receiving information, such as eyes, ears, and taste buds  Characteristics of all living things 5. Homeostasis Homeostasis is the ability of an organism to maintain relatively constant internal conditions. All organ systems contribute to homeostasis Examples: Body temperature : our bodies maintain a constant body temperature. 6. Reproduction Reproduction is the process of producing new organisms of the same type. Two types of reproduction: 1. Sexual reproduction: cells from 2 different parents unite to form the first cell of the new organism (Zygote). 2. Asexual reproduction: new organism is formed from a single parent.  Characteristics of all living things 7. Obtain and use energy (metabolism) All living things obtain energy from their environment or surroundings and use it in different processes as growth, development, reproduction, and excretion Metabolism includes all chemical reactions occurring within an organism Anabolism + Catabolism = Metabolism 1. Anabolism: it is the process of building up complex substances from simpler substances. e.g., photosynthesis process. 1. Catabolism: it is the process of breaking down complex substances into simpler substances to release energy. e.g., digestion.  Characteristics of all living things 8. Adaptation It is the ability of Living organism to adapt to their environment. Adaptations enhance the individual’s ability to survive in a particular environment. Example: Desert plants have succulent waxy leaves and stems to store water and reduce water loss. Levels of Organization  Living Organisms have a high degree of organization Cells : it is the smallest unit of life. Tissue: groups of similar cells performing a specific function. Organ: Groups of tissues that work together to perform closely related functions. Organ systems: a group of organs that perform a broad biological function. Organism: organ systems functioning together make up an organism  Living Organisms have a high degree of organization Population: Groups of individuals of the same species that live in the same area. Community: Groups of different populations that live together and interacting with each other in a defined area. Ecosystem: Groups of all the organisms that live in a particular place, together with their nonliving environment. Biosphere: Part of the Earth in which life exists including land, water, air and atmosphere. Thank You