Presentation on theme: "Chapter 1 : The Science of Life pg. 4"— Presentation transcript:
1 Chapter 1 : The Science of Life pg. 4 Section 1 : The World of Biology
2 Biology- the study of life How is biology important to a person’s daily life and to human society?
3 Knowledge of biology allows us to make informed decisions and know about our health, technology, the food we eat, pollution, diseases, and the environment.
4 Characteristics of Life 1. Organization and Cells2. Response to Stimuli3. Homeostasis4. Metabolism5. Growth and Development6. Reproduction7. Change Through Time
5 1. Organization and Cells Organization- the high degree of order within an organism’s internal and external parts and in its interactions with the living world
6 Organs- structures that carry out specialized jobs within an organ system; made of tissues Tissues- groups of cells that have similar abilitiesCell-the smallest unit that can perform all life’s processes
7 Organelles- tiny structures that carry out functions necessary for the cell to stay alive Examples: mitochondria & Golgi ApparatusBiological molecules- the chemical compounds that provide physical structure and enable other cellular functions and biological molecules are made of ATOMS
8 Organization also includes: Unicellularity-Multicellularity-Single-celledMore than one cell
9 2. Response to StimuliAn organism’s response to a stimulus (a physical or chemical change in the environment)Examples: pupil dilation in response to bright lightWhat are some other examples of an organism responding to a stimulus?
10 3. HomeostasisHomeostasis- the maintenance of a stable level of internal conditions even though environmental conditions are constantly changing.Examples: burning calories to stay warm:Birds fluffing up feathers to keep warm
11 4. MetabolismMetabolism- the sum of all the chemical reactions that take in and transform energy and materials from the environment; getting energy from the food we eatOr……………….photosynthesis
12 5. Growth and Development *All living things grow and increase in size.Growth in living things occurs by cell division and not accumulation of matter such as occurs in crystals(nonliving)Development- the process by which an organism becomes a mature adult
13 6. Reproduction Producing offspring *NOT essential to the survival of an individualDNA transmits heredity information from parent to offspring
14 Why is reproduction an important characteristic of life? Gene- a short segment of DNA that contains the instructions for a single trait of an organismWhy is reproduction an important characteristic of life?*Reproduction is essential to the continuation of a species*
15 Types of Reproduction Asexual Sexual One parent; produces identical offspringEx. bacteria2 parents produce offspring that contain genetic material from both parents; a different individual
16 7. Change Through Time Evolution- changes in a population over time The ability of populations of organisms to change over time is important for survival in a changing world.Also, it explains the diversity of life-forms found on earth today.Evolution- changes in a population over time