Chapter 1: study of life Ms. Mezzetti Lynn English High School Science Department
Chapter 1 Keywords • homeostasis • metabolism • multicellular organism • natural selection • organism • organ • photosynthesis • reproduction • unicellular organism • gene • heterotroph • autotrophs • biology • cells • DNA • development • differentiation • ecology • ecosystem • evolution • evolve
Chapter 1 Objectives • List six unifying themes of biology. • Explain how organisms get the energy they need to survive. • Describe the main difference between the structure of a living thing and that of a nonliving thing. • List six characteristics of life • Describe the hierarchy in nature from atoms to biome
Primordial Earth • Earth is currently theorized to be over 4 billion years old • The first living organisms were single-celled, unicellular organisms-bacteria • Unicellular organism later evolved over time to form the diverse life that now exists on Earth today-over 2.5 million different species and yet many more to be classified
Biology is the study of life Biology studies • the microscopic structure of cells which are the basic unit of life • The interactions between millions of species-ecology • The history of life on earth-evolution
THEMES OF BIOLOGY– SCREIMStability and Homeostasis • All living organisms need to maintain a stable internal environment-this is known ashomeostasis • Internal conditions such as food, water and temperature must be controlled to survive. This is true for all living organisms-unicellular and multicellular
THEMES OF BIOLOGY– SCREIMCell Structure and Function • Cells are the basic unit life - all living organisms are made up of cells • All cells are surrounded by a plasma membrane, contain DNA, ribosomes and cytoplasm-we will learn about all of these • Living organisms can be unicellular such as bacteria and protists or multicellular like plants, fungi and animals • All living organisms are classified as prokaryotes(bacteria) or eukaryotes(all other living organisms)
Cell Structure and Function:unicellular or multicellular? What is this? Prokaryote or Eukaryote?
THEMES OF BIOLOGY– SCREIMReproduction and Inheritance Reproduction– the process by which organisms produce new organisms like themselves. • DNA– hereditary information. Deoxyribonucleic Acid. • In eukaryoticorganisms, DNA is enclosed within a structure of membrane. • In prokaryotic organisms, DNA exists as a loop- • Gene– short segment of DNA. Contains the instructions for development of a single trait. • The DNA in every cell in your body is exactly identical.
THEMES OF BIOLOGY– SCREIM Evolution • Evolution – change over generations. • Natural Selection – organisms with more favorable traits will be more successful at reproduction. • Driven by competition for resources
THEMES OF BIOLOGY– SCREIM Interdependence of Organisms • Ecology– the interactions of organisms between one another and their environment. • Ecosystem– is the environmental community
THEMES OF BIOLOGY– SCREIM Matter, Energy, and Organization • Photosynthesis– the process by which plants capture energy from the sun and convert it to chemical food. • Autotrophs– organisms that make their own food. • Heterotrophs – organisms that get food from the outside environment.
THEMES OF BIOLOGY– SCREIM Matter, Energy and Organization • All living organisms need energy to survive. • Living organisms use different processes to acquire energy- ATP • Plants use photosynthesis to produce their energy-autotrophs • Animals depend on other organisms for their energy-heterotrophs
CHARACTERISTICS OF LIFE-GRROUCH! • To be considered a living organism you must possess these characteristics we will refer to as GRROUCH: • GROW-all living organisms grow and develop • RESPOND- living organisms need to respond to stimuli to survive • REPRODUCE-living organisms reproduce to produce offspring • ORGANIZED-living organisms are organized matter from atoms to cells to body systems • USEENERGY-living organisms need to metabolize energy (ATP) • CELLS-all living organisms are composed of one or more cells • HOMEOSTASIS-all living organisms must maintain a stable internal environment to survive