Biology

1. Biology Bio- = life -ology = the study of Organisms – living things Cell – smallest unit of an organism that can carry on life functions

2. Prokaryotic cell – cell with NO nucleus example: bacteria Eukaryotic cell – cell with a nucleusexample: all organisms EXCEPT bacteria

3. Unicellular – an organism made of only one cellexamples: euglena, amoeba, paramecium Multicellular – an organism made of many cellsexamples: animals, trees, mushrooms

4. Antonie van Leeuwenhoek – made a simple microscope with a glass bead that could magnify up to 270 times

5. Robert Hooke - discovered the “cell” - looked at a piece of cork - said the cells look like little boxes

6. CELL THEORY • All organisms have one or more cells • All cells come from cells (DIVIDE) • Cells are basic units of life Matthias Schleiden – all plants are made of cells Theodor Schwann – all animals are made of cells Rudolph Virchow – cells divide to make new cells

7. Cell Parts and Function Nucleus – control center, directs activities of the cell Cytoplasm – gel-like material inside cell Cell Wall – supports and protects plant cell Cell Membrane – protective layer, allows certain material in and out of cell Chloroplast – green structure in plant cells, allows plants to make their own food

8. Mitochondria – where energy in food is stored then released; POWERHOUSE Ribosomes – makes proteins Endoplasmic reticulum – folded membrane, moves materials in cell Vacuole –storage for food, water, waste Lysosome – breaks down food, waste, and worn out cell parts Golgi Body – packages proteins

9. Moving Cellular Material Cell Membrane –allows certain material in and out of cell Selectively permeable – selects what can enter and leave based on size Passive Transport Systems DO NOT use energy to move substances through the cell

10. 3 Types of Passive Transport Systems • Diffusion – random movement of molecules from higher concentration to lower concentration until they reach equilibrium (ex. Vanilla in balloon)

11. 2. Osmosis – diffusion of water through a cell membrane (ex. Carrot in salt water) 3. Facilitated Diffusion – transport proteins help large molecules, like glucose, enter the cell (ex. Drive through window of McDonalds)

12. Active Transport System – energy is needed to move a substance through membrane, like root cells needing minerals from soil (ex. Going back into a stadium after the game)

13. Endocytosis – cell process that takes in a substance by surrounding it. (ex. How amoeba takes in food) Exocytosis – contents of a vesicle can be released. (ex. Cells in stomach release chemicals to help digest food)

14. Cell Membrane Transport A. Diffusion and Osmosis B. Facilitated Diffusion C. Active Transport D. Endocytosis E. Exocytosis

15. Energy for Life Metabolism – Organisms use energy to carry out activities of life, like making food, breaking down food, building cells, moving materials in and out of cells. The total of all chemical reactions in an organism. Enzyme – causes a change and can be used again

16. Producers – organisms that can make their own food Consumers – organisms that cannot make their own food

17. Photosynthesis – process of changing light energy into chemical energy (use light to make sugars) START: carbon dioxide, water, light energy END: glucose sugar, oxygen Happens in chlorophyll

18. Cellular Respiration – process that breaks down food molecules into simpler substances and releases energy (split glucose using oxygen) START: glucose sugar, oxygen END: carbon dioxide, water, energy C6H12O6+6O2 6CO2+6H2O + energy Happens in mitochondria

19. Click link below http://www.pbs.org/wgbh/nova/methuselah/phot_flash.html

20. Fermentation – process of releasing stored energy without the use of oxygen.enzyme C6H12O6 C2H5OH + 2CO2 yeast cells ferment into ethanol alcohol and carbon dioxide muscle cells ferment into lactic acid and energy C6H12O6 2C3H6O3 + energy

21. Cell Division and Mitosis Why do cells divide? Many organisms start as one cell. That cell divides and become two, two becomes four, four becomes eight, and so on. Multi-cellular organisms grow because cell division increases the number of cells. Even after growth stops, cell division is important. Every day, billions of red blood cells wear out and are replaced. During a few seconds, bone marrow can produce six million red blood cells.

22. Cell Cycle Organisms have a life cycle. Cells also have a life cycle.

23. Onion Root Tip

24. Onion Root Tip

25. Interphase (growth and development) 1. Chromosomes double

26. Mitosis Prophase 1. Centrioles divide move toward poles 2. Nuclear membrane disappears 3. Nucleolus disappears 4. Chromosomes appear 5. Spindle fibers appear

27. Metaphase 1. Chromosomes line up across equator

28. Anaphase 1. Chromosomes move toward poles

29. Telophase (cytoplasm begins to divide) 1. Chromosomes disappear 2. Spindle fibers disappear 3. Nuclear membrane appears 4. Nucleolus appears

30. Cytokinesis – cytoplasm divides Plant cells – cell plate (forms new cell wall) Animal cells – furrow (forms new cell membrane) Plant cell Animal cell

31. Mitosis Movie Click to play movie

32. Mitosis in plant cell

33. Cell division in animal cells and plant cells is similar, but plant cells do not have centrioles and animal cells do not form cell walls. Organisms use cell division to grow, to replace cells, and for asexual reproduction. Asexual reproduction produces organisms with DNA identical to the parent’s DNA. Fission, budding, and regeneration can be used for asexual reproduction.

34. Fission During fission, an organism whose cells do not contain a nucleus copies its genetic material and then divides into two identical organisms. Example: Bacteria uses fission to reproduce

35. Regeneration Regeneration is the process that uses cell division to regrow body parts. Examples: sponges, planaria, sea stars

36. Budding • When the bud on the adult becomes large enough, it breaks away to live on its own Examples: hydra

37. Meiosis and Sexual Reproduction • Sexual reproduction results when an egg and sperm join. This event is called fertilization, and the cell that forms is called the zygote. • Meiosis occurs in the reproductive organs, producing four haploid sex cells. • During meiosis, two divisions of the nucleus occur. • Meiosis ensures that offspring produced by fertilization have the same number of chromosomes as their parents.

38. Sexual reproduction – type of reproduction when two sex cells come together (egg and sperm) Sperm – sex cells formed in the male reproductive organs Egg – sex cells formed in the female reproductive organs Fertiliztion – joining of an egg and sperm Zygote – cell that is formed due to fertilization (diploid) Diploid – when cells have pairs of similar chromosomes Haploid – when cells do NOT have pairs of chromosomes Meiosis – produces haploid sex cells

39. Human 23 46 23

41. Meiosis Movie Click to play movie

42. Meiosis IProphase I Prophase I is similar to prophase in Mitosis In Prophase I, each duplicated chromosome comes near its similar duplicated mate

43. Meiosis IMetaphase I In metaphase I, the pairs of duplicated chromosomes line up in the center of the cell. The centromere of each chromatid pair becomes attached to one spindle fiber, so the chromatids do not separate in anaphase I.

44. Meiosis IAnaphase I In anaphase I, the two pairs of chromatids of each similar pair move away from each other to opposite ends of the cell.

45. Meiosis ITelophase I In telophase I, the cytoplasm divides, and two new cells form.

46. Meiosis IIProphase II In prophase II, the duplicated chromosomes and spindle fibers reappear in each new cell.

47. Meiosis IIMetaphase II In metaphase II, the duplicated chromosomes move to the center of the cell.

48. Meiosis IIAnaphase II The centromere divides during anaphase II, and the chromatids separate and move to opposite ends of the cell.

49. Meiosis IITelophase II As telophase II begins, the spindle fibers disappear, and a nuclear membrane forms around the chromosomes at each end of the cell.

50. Meiosis Summary