Criteria For Life Objective To learn about the
Criteria For Life Objective: To learn about the characteristics of life
Planet Earth
Do Now Using your knowledge of science, define ‘life. ’ Be sure to include any characteristics that living things share. [Responses should be 3 -4 sentences. ]
Biology and Biodiversity • Biology: the study of life and living things • Biodiversity: the variety of species in an area
Finding Nemo
Things You Need to Build a Barrier Reef How can we group these things?
Biotic and Abiotic • Biotic: The living parts of the environment • Abiotic: The nonliving parts of the environment Example: Biotic- Fish, coral, seaweed Abiotic- Water, light, sand
Identify 3 biotic and 3 abiotic factors
Living vs Nonliving Living Nonliving
7 Characteristics of Life 1. 2. 3. 4. 5. 6. 7. Living things are composed of cells Living things have different levels of organization Living things use energy Living things respond to the environment Living things grow and develop Living things reproduce Living things adapt to the environment
Living things are composed of cells Cell Theory • All organisms are composed of one or more cells • Cells are the most basic unit of life • All cells arise from pre-existing, living cells
Why is a baby considered living? Babies started as one cell and by the time they are born have 26 billion! Many of them have specialized functions.
Living things have different levels of organization 5 Levels of organization Cell Tissue Organ System Organism
Why is a baby considered living? Babies have all sorts of body systems! Including skeletal, nervous, immune, digestive, and more! In all of the systems are organs, tissues, and cells!
Living things use energy • Energy is obtained from the sun or other organisms • Respiration: Chemical process by which an organism obtains energy from food materials in order to maintain life functions. *This refers to cellular respiration, not breathing.
Living things use energy • Nutrition: All activities that an organism does to get materials from the environment and prepare them for use • Excretion: Removal of waste products that organism itself has made Steps in Nutrition
Living things use energy • Metabolism: All chemical reactions that occur within the cells of an organism • Synthesis: The process by which an organism builds large molecules from smaller ones
Why is a baby considered living? Babies get energy from their mother’s breast milk and formula! They also sweat and poop!
Living things respond to the environment • Respond to changes in light, sound, heat, chemicals, and movement. • Homeostasis: the ability of an organism to maintain a stable internal environment even when the external environment changes
Living things respond to the environment • Regulation: The coordination and control of activities of an organism and the response to its environment using nerve impulses or hormones
Why is a baby considered living? Babies respond to their environment by crying! They react to loud noises, heat, smells, and more! But, their bodies ability to maintain homeostasis keeps their insides stable!
Living things grow and develop • Development: The series of changes which organisms undergo to become mature • From a lower to a higher state of organization.
Why is a baby considered living? Babies grow! They develop into children, then teenagers, then adults!
Living things reproduce • Reproduction: The process by which organisms produce new organisms of the same type • Sexual and asexual
Why is a baby considered living? Babies are a product of reproduction! Someday, when they develop, they too can have babies!
Living things adapt to the environment • Species adapt NOT individuals • Evolution: the process by which species have changed over time
Why is a baby considered living? Babies are humans! Humans have long history of adaption; evidence shows they evolved from a species of apes!
7 Characteristics of Life 1. 2. 3. 4. 5. 6. 7. Living things are composed of cells Living things have different levels of organization Living things use energy Living things respond to the environment Living things grow and develop Living things reproduce Living things adapt to the environment
Father of Taxonomy • Taxonomy: The study of classification • Carolus Linnaeus – 18 th century Naturalist – Two most important contributions: 1. Hierarchical classification system 2. Binomial Nomenclature
Classification • Classification: The process of grouping organisms • How? By making categories based upon similarities and differences. • Why? Because of the natural human desire for order. Yo u
Binomial Nomenclature • Binomial nomenclature: system for naming things using Genus and species (two names) – Used by all countries, in all languages, to avoid confusion among scientists. – Genus is written first with an Upper case, species is written second with a lower case. Panthera tigris Malus domestica
The Basis for Classification • • • Structural (anatomy and physiology) Biochemical (enzymes, proteins, DNA) Cytological (cell structure) Embryological (development) Behavioral (patterns of actions) Fossil (common ancestor)
Major Taxonomic Groups • Six Kingdoms – Archaebacteria: Oldest life forms – Eubacteria: Most living bacteria – Fungi: Molds, yeasts, mushrooms, etc. – Plantae: Plants – Animalia: Animals – Protista: Single-celled organisms (eukaryotic) S 4
Dichotomous Key • Dichotomous Key: Tool used by biologists to identify an unknown organism • Series of paired statements of anatomical description that leads to an identification. S 5
Identify each bird.
Bird Identification: Answers • • Bird W is Geospiza Bird X is Platyspiza Bird Y is Certhidea Bird Z is Camarhynchus Figure 1. Certhidea Galapagos Finches
Carcharodon carcharias Fin.
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