Introduction to Biology The Scientific Study of Life

Biology scientific study of life ranges from the molecular to the global –microscope to ecosystem includes diversity of life now & in the past

Biological Subjects Cytology Virology Embryology Anatomy Physiology Molecular Biology Genetics Botany Ichthyology Microbiology Zoology Evolutionary Biology Phylogeny Entomology Ecology

Organization 5 distinct kingdoms Bacteria Protista Fungi Plantae Animalia

Organization organisms are placed into a kingdom based on their characteristic all organisms in a kingdom possess the same characteristics

Characteristics of Animalia Kingdom multicellular eukaryotic cells no cell walls heterotrophs- consumers

Characteristics of Life properties shared by all living things Cellular Organization Metabolism Homeostasis Growth & Reproduction Heredity

Cellular Organization all living things are composed of cells –tiny compartments surrounded by a membrane some are made up of only one cell others have trillions

Metabolism all living things use energy all energy originates from the sun plants use this energy in a process called photosynthesis to make sugars we eat plants or animals that have eaten plants energy transferred to us transfer is metabolism

Homeostasis living things have processes that ensures internal environment remains stable

Growth & Reproduction all living things must grow must reproduce

Heredity living things must have genetic system found in molecules of DNA (deoxyribonucleic acid) determines properties of organism genetic code is used to pass information to successive generations transmission of traits is heredity

Organization of L ife

Hierarchy of Organization Chemical or Molecular Atoms  molecules Cells basic unit of structure and function in living things Tissues made of cells similar in structure & function working together to perform a specific activity 4 basic tissues: connective, epithelial, muscle, and nerve Organs made up of tissues that work together to perform a specific activity Examples - heart, brain, skin, etc. Organ Systems groups of two or more tissues working together to perform a specific function Human body has 11 organ systems - circulatory, digestive, endocrine, excretory (urinary), immune (lymphatic), integumentary, muscular, nervous, reproductive, respiratory & skeletal Organisms entire living things that can carry out all basic life processes take in materials, release energy from food, release wastes, grow, respond to the environment reproduce usually made up of organ systems, but an organism may be made up of only one cell

Study of Biology special way of thinking uses empirical or scientific method –self-correcting process for asking questions & observing natures answers separates science from philosophy

Parts of the Scientific Method Observations –made in the real world Question –leads to a question about those observations Hypothesis –testable assumption or prediction Test hypothesis –conduct research Reaffirm theory –reaffirm or disaffirm theory in relation to outcome of research