Introduction to Living Things

1. Introduction to Living Things Ms. Pelullo 2012

2. What is science? What is biology? • Biology is the scientific study of life • What’s life though?!?! • Nonliving things may share some features in common with living things, but only living things show ALL of the characteristics of life.

3. In what ways are living and non-living things alike??

4. In what way are living and non-living things alike? • They are made up of ATOMS & MOLECULES • An “organism” is any one individual living thing. • There is huge DIVERSITY of organisms on earth

5. The Big 8 - Living Things: • Based on a universal genetic code • Grow and develop • Respond to their environment • Are made up of cells • Taken as a group – living things evolve • Obtain and use materials and energy • Maintain a stable internal environment • Reproduce

6. 1. Living Things are based on a Universal Genetic Code • There is a specific molecule used within the cells of ALL living things to store the complex information they need to • Live • Grow • Reproduce • What is this molecule called?? • DNA (Deoxyribonucleic Acid) • DNA is the genetic material of the cell which contains codes for the building of proteins.

7. 2. Living things grow and developBut What’s the difference? Growth Develop • Getting Larger • Size • Height • Weight • Changing Features • Ex: Butterfly life cycle or Puberty Degree of growth and development depends upon the characteristics of the individual species AND the amount of available energy

8. Living things grow and develop(continued) • To Grow • Unicellular organisms will increase in size • Multicellular organisms will increase in size AND increase in the number of cells • Synthesis: making substances for its cells • Assimilate: using these substances for growth/development The amount of growth and development can be limited by how well an organism synthesizes AND assimilates

9. 3. Respond To Their Environment • Stimulus • A signal to which and organism responds • Response • A specific reaction to a stimulus • Stimuli/Responses may be internal (inside the body) or external (outside the body)

10. Examples: Directions: Label each of these examples - put an "S" by the stimulus and an "R" by the response: a) You touch something hot You pull your hand away b) A blowfish becomes larger and extends its spikes -- after it is threatened by a predator

11. 4. Living Things are Made up of Cells • Cells are the basic units of structureand function in living things. • All cells come from other cells • Cell : basic unit of all forms of life

12. 4. Living things are Made up of Cells Multicellular Unicellular • Made up of more than 1 cell • Cells must work together to accomplish the organism’s life processes • Made of only 1 cell • Must accomplish all life activities within one cell

13. 4. Living things are Made up of Cells • Cellular specialization takes place in complex, multicellular organisms

14. 4. Living things are Made up of Cells • Different types of cells perform specific functions as parts of different tissues and organs • May give the cell a unique form to fit its particular functions • This is due to expressing only certain parts of the DNA code common to all the cells in that organism.

15. 5. Living Things are taken as a group, living things Evolve • Pass on traits (characteristics) from one generation to the next by their DNA • Cannot generally choose or change their characteristics • An organisms traits are largely predetermined by their DNA • Though it may be influenced by their environment

16. 5. Living Things are taken as a group, living things Evolve • Examples of Types of Traits: • Physical • Physiological • Behavioral

17. 5. Living Things are taken as a group, living things Evolve

18. What kind of traits are shown? Physical Physiological

19. How do these new traits arise?? • How are traits controlled ?? • Individual’s genes • In sexually reproducing species, variations arise from unique cominations of the mother and father’s genetic material • Variations are differences in organisms • In sexually and asexually reproducing species, variations can also arise from random/chance mutations • Change the genetic material of a cell • Mutations can be helpful, harmful, or have no impact!

20. What’s a Mutation anyway?? • Mutation • Change in the genetic material of a cell

21. Variations may enhance an organism’s ability to survive & reproduce • These traits are referred to as adaptations • What’s an adaptation? • Heritable characteristic that increases an organism’s ability to survive and reproduce in an environment

22. Environment largely dictates what is an adaptation and what is not. • A trait may benefit survival in one environment and hinder survival in another • Ex – think of a snowshoe hare trying to hide in a NJ Forest!

23. *still on #5 • How do populations change/evolve over time??? • Natural Selection • The process by which organisms that are best suited to their environment survive and reproduce most successfully (=survival of the fittest) • Individuals are selected, a species adapts and evolves

24. Example of evolution • Two shades of peppered moths (light/dark) lived simultaneously in England before the industrial age.

25. The trees were light at the time since they were covered in “lichens” (a fungus/algae) • Which moths were harder to spot “before” the Industrial revolution???

26. Birds spotted the darker moths and the population of darker moths decreased • In other words, the “lighter” ones were “selected for” • During the IR, there was so much pollution that the darker lighter colored lichen on the trees were killed, thus making the trees appear darker… • Which moths were harder to spot “after” the IR?

27. Birds spotted the lighter moths now and the population of lighter moths decreased. • In other words, the “darker” ones were “selected for” • This shows how the environment drives natural selection (influences the selection of traits)

28. Not done with #5 yet… • Each time an organism reproduces, there is a chance that the DNA of the offspring will lead to new and different traits which may enhance their survival. • If the trait benefits the organism, the organism is more ‘fit’ for survival and reproduction of another generation of offspring (their genes are getting passed on)

29. The new trait may be passed on to the next generation of offspring • Eventually, if successful then this trait will be present in a greater % of the population • The group of organisms can be said to have adapted to their environment

30. As one adaptation follows another, eventually the species may undergo subtle or even drastic changes. Over time groups of organisms can become different enough from one another that they are considered a new species.

31. Evolution • Change over time • The process by which modern organisms have descended from ancient organisms • Evidence points to a common ancestor of all life forms which dates back over 3.5 billion years.

32. Finally onto #6 – Living Things Obtain and Use Materials & Energy • Materials and energy move between the living (biotic) and nonliving (abiotic) parts of the ecosystem • Materials (atoms, molecules) must be recycled but energy is NOT – therefore a constant supply of energy must enter every ecosystem • Where do we usually get the energy???

33. #6 • Organisms must be able to • Produce or obtain Nutrients • Convert nutrients into usable forms of chemical energy (Making ATP through cellular respiration) • Use these forms of energy to power their life processes

34. A) Organisms must produce/obtain nutrients Heterotrophs Autotrophs • Obtains food by consuming other living things AKA Consumer • Ex: Animals, fungi, bacteria Categories: Herbivores, Omnivores Decomposers • Capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds AKA Producer • Ex: All Plants, bacteria

35. There are different types of autotrophy including Photosynthesis and Chemosynthesis

36. Photosynthesis can be summarized by the following equation 6 CO2 + 6H2O  C6H12O6 + 6 O2

37. B) Organisms must convert the nutrients into usable forms of chemical energy • Make ATP through cellular respiration • Cellular respiration • Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen. • Cellular Respiration can be summarzied by the following chemical equation C6H12O6 + 6 O2 6 CO2 + 6 H2O IMPORTANT: All organisms undergo cellular respiration!

38. How are photosynthesis and cellular respiration related???? • The products of one reaction become the reactants of the other. • In other words, each reaction makes what the other reaction needs. • Photosynthesis is an energy-storing reaction; cellular respiration is an energy-releasing reaction.

40. Important notes to remember -- • Do not confuse cellular respiration with the act of breathing • What’s breathing??? Inhaling/Exhaling – not all organisms do this! • All living organisms (auto/heterotrophs) must undergo some type of cellular respiration to produce ATP

41. C) Organisms will use these forms of energy to power their processes

42. Other Processes • Growth • Reproduction • Excretion of wastes • Respiration • Regulation of cellular activities • Metabolism • ALL LIFE PROCESSES

43. Metabolism • The combination of chemical reactions through which an organism builds up or breaks down materials • When metabolism stops, • An organism CANNOT perform life functions  DEATH  • Special types of metabolic reactions help organisms obtain/use energy from the environment to produce new compounds that • Power life processes – life functions are based on chemical reactions

44. #7 – Living Things Maintain a Stable Internal Environment • Homeostasis • Relatively constant internal physical and chemical conditions that organisms maintain • Try to stay the same inside no matter what goes on outside • Examples: regulation of body temperature • When its cold humans --- • When its hot, we ---- • We want to maintain our body temp around 98F

46. Last But Not Least #8 – Reproduction • The process of reproduction ensures that DNA is passed from parent(s) to offspring • Is reproduction necessary for the survival for the individual or the species? • Species!

47. Two Types of Reproduction Asexual Sexual • Involving a single parent that results in offspring that are genetically identical to the parent • Cells from two parents unite to form the first cell of a new organism Either method of reproduction has the potential to be very successful - depending on the species and its environment. Some organisms can undergo both asexual and sexual reproduction.

50. Taxonomy • Science of Classification • Involves grouping and naming organisms • What is a species?? • A group of similar organisms that can breed and produce fertile offspring • How do we group and name species? • Named using a system of binomial nomenclature • Example – Humans • Homo sapiens • Homo = genus • sapiens = species