BIOLOGY

2. BIOLOGY • Greek • BIO = life • LOGIA = study of

3. BIOLOGY • Biology—the scientific study of living things • “Living things”—All the diverse organisms descended from a single-celled ancestor (a single common ancestor)

4. Define - “LIFE” • Dictionary - “the condition which distinguishes animals & plants from inorganic objects & dead organisms” • Dead (Dictionary) = “deprived of life”

5. Scientific Principles • Natural Causality - all events can be traced to natural causes • Uniformity in Time & Space - forces (natural laws) acting today are the same as those of past • Common Perception - all humans perceive natural events in the same way (senses)

6. Scientific Principles • Scientific Principles Underlie All Scientific Inquiry • Natural Causality Is the Principle That All Events Can Be Traced to Natural Causes • The Natural Laws That Govern Events Apply Everywhere and for All Time • Scientific Inquiry Is Based on the Assumption That People Perceive Natural Events in Similar Ways • The Scientific Method Is the Basis for Scientific Inquiry • Science Is a Human Endeavor

7. Common Perception does not mean or result in Common Interpretation. • Interpretation is influenced by external factors, such as, the cultural, social, and philosophical background of the observer(s). • Science focuses on quantifiable measures NOT abstract value systems.

8. Life Is More Than the Sum of Its Parts • Biologists study life by thinking about it at different levels of organization • Nature’s organization begins at the level of atoms, and extends through the biosphere • The quality of life emerges at the level of the cell • Each level of organization in nature has emergent properties– a characteristic of a system that does not appear in any of its component parts

9. A Pattern in Life’s Organization • Atoms • Fundamental building blocks of all substances • Molecules • Consisting of two or more atoms • Cell • The smallest unit of life • Tissue • Specialized cells organized to perform a collective function

10. A Pattern in Life’s Organization • Organ • Structural unit of interacting tissues. • Organ system • A set of interacting organs • Multicelled organism • An individual consisting of one or more cells

11. A Pattern in Life’s Organization • Population • Individuals of the same species in the same area • Community • Populations of all species in the same area • Ecosystem • A community and its environment • Biosphere • All regions of the Earth where organisms live

12. Life’s Levels of Organization atom molecule cell tissue organ organ system

13. Levels of Organization in Nature

14. Levels of Organization in Nature

15. How do living things differ from nonliving things? • All things, living or not, consist of the same building blocks—atoms; atoms join as molecules. • The unique properties of life emerge as certain kinds of molecules become organized into cells. • Higher levels of life’s organization include multicelled organisms, populations, communities, ecosystems, and the biosphere. • Emergent properties occur at each successive level of life’s organization.

16. How Living Things Are Alike • Continual inputs of energy and the cycling of materials maintain life’s complex organization • Organisms sense and respond to change • All organisms use information in the DNA they inherited from their parent or parents to develop and function

17. Attributes of Living Organisms

18. Homeostasis • Homeostasis • Organisms use receptors to help keep conditions in their internal environment within ranges that their cells can tolerate

19. Energy and Life’s Organization • Energy • The capacity to do work • Not cycled; flows through the world of life in one direction • Nutrients • Atoms or molecules essential in growth and survival that an organism cannot make for itself • Cycled between organisms and the environment

20. Producers and Consumers • Producers • Acquire energy and raw materials from the environment • Make their own food (photosynthesis) • Consumers • Cannot make their own food • Get energy by eating producers and other organisms

21. Resources • Living Things Acquire and Use Materials and Energy • Living things acquire energy and nutrients from the environment

23. sunlight energy A Producers harvest energy from the environment. Some of that energy flows from producers to consumers. Producers plants and other self-feeding organisms B Nutrients that become incorporated into the cells of producers and consumers are eventually released by decomposition. Some cycle back to producers. Consumers animals, most fungi, many protists, bacteria C All of the energy that enters the world of life eventually flows out of it, mainly as heat released back to the environment.

24. A Energy inputs from the environment flow through producers, then consumers. energy input, mainly from sunlight B Nutrients become incorporated into the cells of producers and consumers. Some nutrients released by decomposition cycle back to producers. PRODUCERS plants and other self-feeding organisms nutrient cycling CONSUMERS C All energy that enters an ecosystem eventually flows out of it, mainly as heat. animals, most fungi, many protists, bacteria energy output, mainly heat

25. Organisms Sense and Respond to Change • Organisms sense andrespond to change both inside and outside the body • The body’s internal environment consists of all body fluids outside of cells • The internal environment must be kept within certain ranges of composition, temperature, and other conditions • By sensing and adjusting to change, organisms keep conditions in the internal environment within a range that favors cell survival (homeostasis)

26. Response to a Stimulus

27. Organisms Use DNA • DNA is the basis of similarities in form and function among organisms • Details of DNA molecules differ – the source of life’s diversity • DNA • Deoxyribonucleic acid • Carries hereditary information that guides development and functioning

28. Development and Growth • DNA guides ongoing metabolic activities that sustain the individual through its lifetime • Development • Multistep process by which the first cell of a new individual becomes a multicelled adult GMR • Growth • In multicelled species, an increase in the number, size, and volume of cells • Maintenance • In multicelled species, the upkeep, repair, and/or replacement of cells • All organisms receive their DNA from one or more parents • Reproductionincludes various processes by which individuals produce offspring • Inheritancerefers to the transmission of DNA to offspring

29. How are all living things alike? • A one-way flow of energy and a cycling of nutrients sustain life’s organization. • Organisms sense and respond to conditions inside and outside themselves; they make adjustments that keep conditions in their internal environment within a range that favors cell survival, a process called homeostasis. • Organisms develop and function based on information encoded in their DNA, which they inherit from their parents. DNA is the basis of similarities and differences in form and function

30. How Living Things Differ • Living things differ in their observable characteristics • Various classification schemes help us organize this variation, which we call Earth’s biodiversity • biodiversity • Scope of variation among living organisms

31. Summary of Life’s Characteristics

32. Basics of Classification • Organisms can be classified into broad groups depending on whether they have a nucleus or not • Nucleus • A sac with two membranes that encloses and protects a cell’s DNA

33. Organisms With No Nucleus • Bacteria and archaea are two types of organisms whose DNA is not contained within a nucleus • Bacteria • The most diverse and well-known group of single-celled organisms that lack a nucleus • Archaea • Single-celled organisms that lack a nucleus but are more closely related to eukaryotes than to bacteria

34. Bacteria – no nucleus Clockwise from upper left, a bacterium with a row of iron crystals that acts like a tiny compass; a common resident of cat and dog stomachs; spiral cyanobacteria; types found in dental plaque.

35. Archaea – no nucleus Archaea resemble bacteria, but are more closely related to eukaryotes. Left, an archaeon from volcanic ocean sediments. Right, two types of archaea from a seafloor hydrothermal vent.

36. ANIMATED FIGURE: Life's diversity To play movie you must be in Slide Show Mode PC Users: Please wait for content to load, then click to play Mac Users: CLICK HERE

37. Eukaryotes • Eukaryotes are organisms whose DNA is contained within a nucleus • Some eukaryotes live as individual cells; others are multicelled • Eukaryotic cells are typically larger and more complex than bacteria or archaea

38. Protists • Protistsare the simplest eukaryotes • As a group they vary a great deal, from single-celled consumers to giant, multicelled producers • Many biologists view “protists” as several major groups

39. Protists Protists are a group of extremely diverse eukaryotes that range from giant multicelled seaweeds to microscopic single cells. Many biologists are now viewing “protists” as several major groups.

40. A protist (domain Eukarya) contractile vacuole food vacuoles oral groove (“mouth”) 10 micrometers This light micrograph of a Paramecium illustrates the complexity of these large, normally single, eukaryotic cells. Some protists photosynthesize, but others ingest or absorb their food. Many, including Paramecium, are mobile, moving with cilia or flagella.

41. Fungi • Fungi are multicelled eukaryotes such as mushrooms • Many are decomposers • All are consumers that secrete substances that break down food outside of the body and absorb the released nutrients

42. Fungi Fungi are eukaryotes. Most are multicelled. Different kinds are parasites, pathogens, or decomposers. Without decomposers such as fungi, communities would be buried in their own wastes.

43. The kingdom Fungi (domain Eukarya) An exotic mushroom found in Peru. Most fungi are multicellular. Fungi generally absorb their food, which is usually the dead bodies or wastes of plants and animals. The food is digested by enzymes secreted outside the fungal body. Most fungi cannot move.

44. Plants • Plants are multicelled eukaryotes that live on land or in freshwater environments • Most are photosynthetic producers • Plants and other photosynthesizers also serve as food for most of the other organisms in the biosphere

45. Plants Plants are multicelled eukaryotes, most of which are photosynthetic. Nearly all have roots, stems, and leaves. Plants are the primary producers in land ecosystems.

46. The kingdom Plantae (domain Eukarya) This butterfly weed represents the flowering plants, the dominant members of the kingdom Plantae. Flowering plants owe much of their success to mutually beneficial relationships with animals, such as these pearl crescent butterflies, in which the flower provides food and the insect carries pollen from flower to flower, fertilizing them. Plants are multicellular, nonmotile eukaryotes that acquire nutrients by photosynthesis.

47. Animals • Animals • Multicelled consumers that ingest tissues or juices of other organisms • Herbivores graze; carnivores eat meat; scavengers eat remains of other organisms; parasites withdraw nutrients from the tissues of a host • Develop through stages that lead to the adult form • Actively move about during at least part of their lives

48. Animals Animals are multicelled eukaryotes that ingest tissues or juices of other organisms. All actively move about during at least part of their life.

49. The kingdom Animalia (domain Eukarya) A wrasse rests on a soft coral. Animals are multicellular; animal bodies consist of a wide assortment of tissues and organs composed of specialized cell types. Most animals can move and respond rapidly to stimuli. The coral is a member of the largest group of animals: the invertebrates, which lack a backbone. This group also includes insects and mollusks. The wrasse is a vertebrate; like humans, it has a backbone.

50. Organizing Information About Species • Each type of organism, or species, is given a unique name • We define and group species based on shared traits • Taxonomy is the science of naming and classifying species