THE CHARACTERISTICS OF LIFE 1A Living Environment Murtaugh

ESSENTIAL QUESTIONS  What are the major unifying themes between the different disciplines of science?  Why is it important to study living organisms?  Why and how are living and non-living organisms alike and different?  How can you differentiate between living and non- living?  How do living organisms interact with their surroundings?

VOCABULARY:  Alive/Life- exhibiting all characteristics of life  Biology- study of life  Homeostasis –maintaining a stable internal environment  Nonliving- showing some or none of the characteristics of life.  Regulation- to control  Stimulation- responding to the environment  Synthesis- to produce or make

SCIENCE IS AN ORGANIZED WAY OF INVESTIGATING THE NATURAL WORLD.  Biology – the study of life  Biology is linked to other sciences by major unifying themes ie.) physics – locomotion  What are the major unifying themes between the different disciplines of science?

UNIFYING THEMES FOR ALL OF THE SCIENCES  Energy – required to grow and reproduce  Evolution – a change in living things over time  Patterns of change – life cycle of humans, leaf drop of trees in the fall, the moon cycle  Scale and Structure – all organisms are of a particular size and arranged in a certain way  Systems and Interactions – how organisms interact with their environment (ecosystem)  Stability – systems to maintain equilibrium (homeostasis)  Unity and Diversity – the similarities and the differences that are formed in nature, ie.) a protist and a killer whale!

CHARACTERISTICS OF LIVING THINGS 1.Are made up of basic units called CELLS. 2.Are based on universal genetic code – DNA (deoxyribonucleic acid). 3.Uses Energy (metabolism) 4.Have a definite form and limited size. 5.Have a limited life span.

CHARACTERISTICS OF LIVING THINGS (CONTINUED) 6.Grows 7.Reproduces 8.Responds to environmental changes (stimulation/maintains homeostasis) 9.Evolves, adapts or changes over time

DIFFERENCE BETWEEN LIVING AND NONLIVING  Nonliving things may show one or more of these characteristics, but never all of them!!!!!!!!!!! ie) Viruses Have genetic material Uses hosts to reproduce Can mutate and evolve  DO NOT metabolize  DO NOT respond to stimuli  DO NOT have components of cells Viruses are NOT living

WHAT IS A LIFE PROCESS?  All living things carry out a variety of “life” processes (a set of steps) that help maintain a constant internal environment.  Homeostasis – all processes that help maintain a constant internal environment  This is not a life process but is the result of all life processes working correctly

LIFE PROCESSES 1. Nutrition – taking materials from the external environment and changing them into usable forms. Ingestion- taking in food from the environment OR Digestion – breakdown of food materials into simpler forms that an organism can use

LIFE PROCESSES 2. Transport – process of substances entering and leaving cells to become distributed to other cells. ex) Circulatory System 3. Respiration – process of using materials to make and release chemical E (ATP). ***This is not breathing***

LIFE PROCESSES 4. Synthesis – combining smaller or simpler substances to form more complex substances, to make ex) glucose to form carbohydrates (dehydration synthesis) 5. Growth – the increase in size of the cell (s) *** some cells grow in size while others become more specialized (differentiation)

LIFE PROCESSES 6. Excretion – removal of wastes from an organism (NOT pooping- that is elimination) *** remember, one organisms waste, is another organisms requirement for life! ie) Plants and Humans 7. Regulation – all the activities that help an organism respond to its environment and maintain equilibrium (what is normal)

LIFE PROCESSES 8. Reproduction – the process by which organisms make new organisms of their own kind Two types: Asexual – involving 1 parent, offspring are identical to the parent Sexual – involves 2 parents, offspring are similar, but not identical to the parent

LIFE PROCESSES 9. Metabolism – all the chemical reactions that occur within the cells of an organism. It is a process that involves the continuous release and use of energy! How ? 1. breakdown of complex substances (hydrolysis) 2. building of complex substances from simpler ones (dehydration synthesis) Metabolism includes nutrition, synthesis and respiration!!!!

ORGANIZATION OF LIFE Cell- smallest unit of life Tissue Organ Organ System Organism- most complex part of life