1. Honors Biology Unit 1: The Life of the Cell A: Characteristics of Life Core Concept #1: All forms of life share common features

2. Structural and functional unit of life Two kinds of cells: 1) prokaryotic – no nucleus - small, simple - quick, easy reproduction - fast exchange with environment 1. Made of one or more cells

3. Eukaryotic Cells Larger, complex, have nucleus Many organelles, compartmentalized Parts for specific cell functions Cells can specialize – form tissues Can form multicellular organisms

4. Two Kinds of Cells

5. All cells share some features Enclosed by selective membrane Contain cytoplasm, DNA, complex molecules Make any needed substances from raw materials from environment

6. 2. Common genetic code DNA - Deoxyribonucleic Acid a.Instructions for all life functions b.“Gene” – one section on a DNA strand - codes for one trait b.Cells copy DNA and pass it to offspring c.“Universal” code – same for all organisms - Shows unity of life A C T G

7. Shared genetic code makes gene engineering possible Examples: Human insulin Drought-resistance GM foods

8. Genetically Modified Corn Bacteria – toxin kills worm Gene for toxin put into corn Worm eats corn  gene makes toxin  toxin kills worm Why not hurt humans? Concentration too small

9. DNA is unique to an individual DNA “fingerprint” - a pattern of stripes/bands - different for everyone - depends on order of ACTG

10. 3. Obtain and Use Energy a. Food – for energy and raw materials b.Autotrophs - Producers b.Make their own food c.Most use sunlight - photosynthetic d.Combine water and CO 2 to make basic carbs e.Some use chemical energy - chemosynthetic f.Base of all food chains c.Heterotrophs - Consumers a. find food in environment

11. Interdependence in Nature Core concept #2: All forms of life depend on each other and on physical parts of environment a.Biotic and abiotic b.Take in light, food, water, air - For energy, material for growth and repair c.Send out wastes, die d.Decomposers (saprobes/saprophytes) - break down waste, recycle chemicals

12. Web of Life

13. Chemicals CYCLE Environment  autotrophs  heterotrophs  saprobes  back to environment Light energy  chemical energy in food  energy used for life functions  some lost as heat Energy does NOT cycle

15. 4. Grow and Develop a.Grow – increase in size (add more cells) b.Develop – change while maturing a.Multicelled begin as a single cell b.Cells copy and specialize (differentiate) c.Form many different kinds of cells d.Organisms change as they grow older

16. Bones grow longer with maturity

17. Stem Cells a.Can become specific kinds of cells b.Some genes are turned on, some off c.Depends on chemical signals from their environment

18. With many complex chemicals Have recognizable size and shape Cells and organisms – different parts perform different functions 5. ARE ORGANIZED

19. Core Concept #3: Life proceeds from simple to more complex a. Cells differentiate  specialized cells b.Different kinds of cells form tissues c. Different kinds of tissues form organs d.Organs work together to form organ systems e.Body systems work together to keep an organism alive. Multicellular - Levels of Organization

20. Skin Tissue Many kinds of cells work together Coating/lining cells “Skin” cells Muscle cells Fat cells Blood/nerve cells Gland cells

21. Cells  tissues  organs  organ systems  organism

22. Environment – Levels of Organization Organism – individual living thing Population – members of one species living in same area Community – all living things living in the same area Ecosystem – biotic and abiotic in one area Biosphere – layer on earth that supports life

23. 6. Reproduce a.New cells form by cell division b.Make new cells or a new organism c.Asexual – one parent - identical offspring c.Sexual – two parents - offspring gets genes from both parents - must be same species

24. Is mule a species? Parents – horse and donkey Hybrid - offspring from two closely-related species - cannot reproduce  NOT a species (species - fertile young)

25. 7. Respond to environment a. Stimulus - causes a reaction b. Response - reaction to a stimulus c. Internal or external stimuli d. Must keep homeostasis (constant internal conditions)

26. 8. Evolve – Biology’s Central Unifying Theme a.Species can slowly change over time to better fit an environment b.Traits fit environment  survive and reproduce  pass on traits c.Individual organisms DO NOT evolve d.Earliest life 3.5 billion years ago

27. Darwin’s Theory of Evolution Nature selects those best suited to survive - reproduce and pass on helpful traits - species slowly change over time

28. Core Concept #4: Evolution explains Unity and Diversity Life is unified  shared ancestry all living things have same life traits do same life functions same chemical make- up and processes

29. Life is Diverse Living things are diverse - special features for different environments

30. Diversity of Life 6 Kingdom System of Classification 1. Archaebacteria – oldest kind of bacteria 2. Eubacteria – most bacteria 3. Protista – one-celled eukaryotes 4. Fungi – mostly decomposers 5. Plantae – multicelled photosynthetics 6. Animalia – multicelled heterotrophs

31. 6 Kingdoms

33. 3 Domain System Archaea – Archaebacteria Bacteria – Eubacteria Eukarya – all eukaryotic organisms

34. Newest Tree of Life Shares genes with Eukarya

35. Structure and Function a.“Form follows function” b.Features evolve to perform a function better c.Different environments need different kinds of adaptations

36. Are viruses alive? NOT part of living kingdoms LACK MOST traits of life, have only 3: – Have DNA and protein – Organized, recognizable size and shape – Can evolve BETWEEN living and nonliving

37. Core Concepts in Biology 1.All life forms share common features – DNA, life traits, cell basic unit of life 2. Living things interact with each other and with the environment (food chain, cycling) 3. Life proceeds from simple to complex - levels of organization in organism, in environment 4. Evolution explains unity and diversity a. Unity - All life forms share common traits - cells, DNA, life functions b. Diversity - Life evolves to suit its environment – form and function

38. Life Processes How do living things stay alive? All life processes work to maintain homeostasis (stable internal conditions) Metabolism – all the chemical processes an organism performs Includes: Anabolic – build a molecule Catabolic – break a molecule down

39. 1. Cellular Respiration Make energy for all life processes Release energy in food molecules NOT digestion, NOT “breathing” Aerobic – gets max energy Anaerobic

40. 2. Nutrition Get or make food; process it for cells to use Nutrients – for energy, raw materials 1.Autotrophs (producers) a. Make their own food b. Photosynthesis c. Base for all food chains d. Plants, algae, some bacteria

41. 2. Heterotrophs (consumers) a. Ingest – take in food from environment b. Digest – break large molecules down c. animals, fungi, many bacteria 3. Saprobes (decomposers) a. Break down wastes, dead organisms b. Recycle nutrient molecules c. Fungi, many bacteria

42. Digestive System Breaks down food into molecules small enough to enter cells Nutrients and water absorbed by cells Liver, pancreas, and others make enzymes

43. 3. Transport Circulate materials in a cell or organism Cross cell membranes Spread throughout cell Deliver needed materials, remove wastes Multicellular – need way to transport throughout organism

44. Animals: circulatory system - heart, blood, vessels Plants : transport tissue (veins)

45. 4. Excretion Remove metabolic wastes Out of cell or organism  environment Wastes are toxic Animals have excretory system Kidneys, skin, liver, lungs Plants have pores in leaves

46. Excretory System in Humans Kidneys – filter blood Liver – detoxify wastes Lungs – exhale CO2 Skin - sweat

47. 5. Synthesis Cells make any needed substance Use molecules from food or raw materials in environment Use energy from cellular respiration Example: make muscle tissue from protein

48. 6. Reproduction Make new cells or new organism New cells – for growth, repair New organism – continues the species

49. 7. Grow and Develop Increase in size and mature One cell  multicellular Develop: cells differentiate Egg  embryo  young  adult

50. 8. Regulation Control rate and kinds of chemical reactions Respond to stimuli Keep homeostasis Unicellular and Plants – chemical messages Animals – nerves and chemicals

51. Nervous system Electric signals along nerves Fast but short-lived Endocrine system Hormones sent into blood stream Cause response only in specific tissue Slower, but last longer Example: adrenaline, growth hormone Plants have hormones, but not nerves

52. Endocrine System Hormones made in different endocrine organs control specific life functions.

53. The Process of Science Evidence: can be observed or measured 1. Discovery science - tries to describe nature 2. Experimental science - tries to explain nature - hypothesis – possible answer/ solution - can be tested Question  hypothesis  test it  confirmation

54. Independent or Dependent? Variables – affect outcome Controlled Experiment – change ONE variable Independent variable – the one you change “Manipulated” Dependent variable – depends on the independent variable “Responding”

55. Eastern coral snake (poisonous)

56. Scarlet king snake (nonpoisonous)

57. Artificial snakes: king snake (left); brown snake (right)

58. Results of mimicry experiment Percent of total attacks on artificial snakes 100 80 60 40 20 0 83% 17% 16% 84% Artificial king snakes Artificial brown snakes Coral snakes absent Coral snakes present