1. Biology Unit 1 Fall 2015 Ms. Taylor PVMHS 1

2. 2 Biological Theory Concept Cell All organisms are composed of cells and new cells only come from preexisting cells Gene Organisms contain coded information that dictates their form, function, and behavior Evolution All living things have a common ancestor, but each is adapted to a particular way of life Homeostasis The internal environment of an organism stays relatively constant within a range protective of life Ecosystem Organisms are members of populations that interact with each other and with the physical environment within a particular locale

3. Levels of biological organization Atoms – smallest portions of an element Combine themselves with other Atoms to form Molecules Consists of a nucleus, neutrons and protons and one or more electrons bound to the nucleus by electrical attraction 3 calcuttahams.com

4. Levels of biological organization Molecules – atoms combine A molecule is formed when two or more atoms are joined together chemically 4 harvardindependent.com

5. Characteristics of Living Things Cellular Organization: - Unicellular- Single celled organism - Multi Cellular- Organism composed of many cells 5

6. Characteristics of Living Things Contain similar chemicals: 1. Water 2. Carbohydrate 3. Proteins 4. Lipids 5. Nucleic Acids 6

7. Characteristics of Living Things Use Energy: ALL organisms need source of energy Heterotrophs- Can not make their own food, need to eat Autotrophs- Produce their own food 7

8. Characteristics of Living Things Grow and Develop: Organisms become larger when they grow and change to produce a more complex organism when they develop 8

9. Characteristics of Living Things Respond to their surroundings: A change in an organisms surroundings causes it to react, this is called stimulus 9

10. Characteristics of Living Things Reproduce: To produce offspring that are similar to the parents 10

11. 11 Biosphere Regions of the Earth’s crust, waters, and atmosphere inhabited by living things Ecosystem A community plus the physical environment Community Interacting populations in a particular area Population Organisms of the same species in a particular area Organism An individual; complex individuals contain organ systems Levels of biological organization

12. 12 THE THEORY OF HOMEOSTASIS Organisms Are Homeostatic

13. Organisms regulate their internal environment Theory of homeostasis Cells and organisms have an internal environment and that cells regulate this environment so that it stays fairly constant Response to stimuli Ability to respond to stimuli assists the homeostatic ability of organisms All together, daily activities are termed the behavior of the organism Behavior of an organism often assists homeostasis 13

14. 14 THE THEORY OF ECOSYSTEMS Organisms Live in Ecosystems

15. The biosphere is divided into ecosystems Theory of ecosystems Organisms form units in which they interact with the biotic (living) and abiotic (nonliving) components of the environment Ecosystems are characterized by chemical cycling and energy flow Begin when plants take in solar energy and inorganic nutrients to produce food by photosynthesis Climate largely determines where different ecosystems are found in the biosphere 15

16. 16 THE THEORY OF EVOLUTION Organisms Are Related and Adapted to Their Environment

17. The ancestry of species can be determined Theory of evolution Organisms have shared characteristics because of common descent Evolutionary tree Traces the ancestry of a group to a common ancestor Traced using molecular data, fossils record, anatomy and physiology, and embryology Natural selection is the mechanism that results in adaptation to the environment Only species (types of organisms) evolve and not individual organisms 17

18. 18 bird characteristics reptile characteristics claws teeth feathers tail with vertebrae Archeopteryx

19. An evolutionary tree shows how the ancestry of Archaeopteryx can be traced to a common ancestor with crocodiles and dinosaurs. 19 Crocodilians Past Time Present Dinosaurs Archaeopteryx common ancestor common ancestor (reptilian)

20. Prokaryotes vs. Eukaryotes Prokaryotes: molecules surrounded by a membrane and cell wall Eukaryotes: Organisms whose cells contain a true nucleus 20 ebi.ac.uk library.thinkquest.org

21. Evolutionary relationships help biologists group organisms Domains Bacteria Prokaryotes Archaea Prokaryotes Eukarya Eukaryotes Protists, Plants, Fungi, and Animals 21

22. Domain Eukarya 1 - 22 Protists Paramecium, a unicellular protozoan Algae, protozoans, slime molds, and water molds Complex single cell (sometimes filaments, colonies, or even multicellular) Absorb, photosynthesize, or ingest food 1 µm KINGDOM: Plants Certain algae, mosses, ferns, conifers, and flowering plants Multicellular, usually with specialized tissues, containing complex cells Photosynthesize food Passiflora, passion flower, a flowering plant KINGDOM: Fungi Coprinus, a shaggy mane mushroom Molds, mushrooms, yeasts, and ringworms Mostly multicellular filaments with specialized, complex cells Absorb food Vulpes, a red fox Sponges, worms, insects, fishes, frogs, turtles, birds, and mammals Multicellular with specialized tissues containing complex cells Ingest food KINGDOM: Animals

23. The Theory of Evolution The idea that there is a “Common descent with modification” 23 mhhe.com

24. Charles Darwin The Father of evolution Concluded that “Natural Selection” brings about adaptations to the environment Adaptation to various environments accounts for the diversity of life on Earth 24 crystalinks.com

25. Natural Selection Mutations introduce variations Some aspect of environment (abiotic or biotic) selects which traits are more apt to be passed on to the next generation Living things having advantageous traits and can produce more offspring than those lacking them 25

26. Rockhopper penguins have become adapted to living in the waters of Antarctic 26

27. Evolution from a common ancestor accounts for the characteristics of life 1. Life is organized 2. Life uses materials and energy 3. Life reproduces 4. Life is homeostatic 5. Life responds to stimuli 6. Life forms ecosystems 7. Life evolves 27

28. Concepts Scientific method helps scientists come to conclusions 5 theories (cell, gene, homeostasis, ecosystems, evolution) All theories of biology are related Characteristics of life All life-forms share similar characteristics because they can trace their ancestry to a common source 28

29. Thank you for your attention 29