1. We all have these in common. 6 Characteristics of Life

2. Living things show all these 6 characteristics: 1.Living things are made up of units called cells. a.Every organism is composed of at least one cell. 1.) single-celled or unicellular 2.) many-celled or multicellular

3. b. There are two broad categories of cells: 1)prokaryotic—no organized nucleus nor membrane bound organelles; found in bacteria and cyanobacteria 2)eukaryotic—do have an organized nucleus and membrane-bound organelles such as Golgi apparatus and mitochondria. All other organisms such as plants and animals have this kind of cell.

4. 2.Living things reproduce, grow and repair themselves. There are two basic kinds of reproduction: a)Asexual—only one parent and all offspring are identical; for example, binary fission of bacteria or amoebas. b)Sexual—two cells from different parents unite to produce the first cell of a new organism.

7. 3. Living things require energy. a)The combination of chemical reactions through which an organism builds up or breaks down materials as it carries out its life processes is called metabolism. b)Autotrophs (also called producers)—plants, most algae, and some bacteria obtain their energy directly from the sun through photosynthesis.

8. c) Heterotrophs (also called consumers)—most other organisms, rely on the energy stored during photosynthesis. 1.Herbivores—eat plants and other photosynthesizing organisms 2.Carnivores—eat the herbivores or other carnivores 3.Omnivores—eat both plants and animals 4.Decomposers—such as bacteria and fungi; obtain energy from the remains of organisms that have died

10. 4. Living things respond to their environment. a)Organisms detect and respond to stimuli from their environment. b)A stimulus is a signal to which an organism responds. c)External stimuli include temperature and light. d)Internal stimuli come from within, such as blood sugar level or feeling thirsty.

11. 5. Living things have a life span;living things change over time (living things evolve). a)Plants have adapted to living in dry and hot deserts. b)Fossils of ancient organisms can be used to show how organisms have changed over time.

12. 6. Living things produce waste. Your kidneys filter waste from your blood. Your lungs exhale C02, your body excretes waste products from your food and drink.

13. 1.Organism 2.Organ System 3.Organ 4.Tissue 5.Cell

14. Cell Structure and Function Notes Discovery of the Cell: Mid 1600’s scientists began using microscopes to observe living things Robert Hooke used microscope to observe thin slice of cork—dead plant material Cork seemed to be made of box-like chambers—Hooke called cells Anton van Leeuwenhoek discovered living cells in pond water

15. Cell Theory: All living things composed of cells Cells are the basic unit of structure and function in living things New cells are produced from existing cells

16. Cell and its Environment: Organisms made of one cell— unicellular organisms Ex: bacteria Organisms made of many cells— multicellular organisms Ex: plants, animals

17. Each cell must be in “balance” with its environment, exchange food, waste, H 2 O, CO 2, O 2 etc. Process by which organisms maintain a relatively stable internal environment—homeostasis

18. Cell: Organisms that do not have a distinct nucleus— prokaryotic (PRO = NO) Ex: bacteria Organisms with cells that have true nucleus and organelles—eukaryotic (EU = TRUE) Ex: plants, animals, fungi

19. Cell Parts and Their Functions: Specialized cell parts called organelles— “little organs”

20. 1.Cell membrane—determines what goes in and out of the cell

21. 2. Cytoplasm—gel-like medium that holds the organelles in position

22. 3. Nucleus—control center of the cell Double membrane that surrounds the nucleus— nuclear membrane Hereditary information inside the nucleus— chromatin (DNA)

23. 4. Ribosomes—makes proteins

24. 5. Rough Endoplasmic Reticulum (rough ER)— makes and transports proteins within the cell Called rough ER because of the ribosomes found on its surface

25. 6.Smooth Endoplasmic Reticulum (smooth ER)—makes and transport lipids and other materials within the cell Called smooth ER because no ribosomes found on its surface

26. 7.Cytoskeleton—network of protein filaments that helps cell maintain its shape

27. 8.Golgi apparatus—processes and packages proteins and other substances produced in the ER

28. 9.Mitochondria—energy source of the cell (powerhouse)

29. 10.Vacuoles—sac-like structures for storage Plant cells usually contain a large vacuole that fills most of the cell—pressure from this large vacuole helps plants support themselves

30. Found in animal cells only: 11.Lysosomes—cleans up the cell and digests unwanted materials

31. Found in plant cells only: 12.Cell wall—provides support and protection for cell Composed mainly of cellulose (plant starch)— fiber for our diet 13.Chloroplast—makes glucose using the energy from the sun (photosynthesis)

32. Specialized Parts for movement: 1. Cilia (like little hairs)2. Flagella (like a tail)

33. Specialized Cells: Different cells in your body do different jobs. The structure (how it’s built) of cells matches the function (what it does).

34. Plant Examples: 1.Leaf cell—contains many chloroplasts to maximize photosynthesis 2.Root cell (potato)— contains many vacuoles to maximize water and starch storage

35. chloroplas t Animal Examples: 1.Epithelial cells—have villi to increase nutrient absorption; found in the intestines

36. 2.Muscle cells—contain many mitochondria to produce more energy for movement

37. 3.Nerve cells—have fibers called dendrites that allow nerve cells to communicate with each other