Levels of Organization 2 Organ System 1 Organism Cell 6 Organelle 3 Organ Tissue 5 4 PAGE 3 What are the differences between plant & animal cells? circular shape square shape large vacuole centriole chloroplasts cell wall small vacuole PAGE 3 Biotic soil earthworm vs Abiotic maple tree sunlight mushroom oxygen human PAGE 4 How do little elephants grow up to be BIG elephants? A. Living Organisms have a Life Cycle 1. Begins with the organism’s formation 2. Followed by growth & development 3. Ends in death PAGE 4 B. Cells also have life cycles. C. The cell cycle is a series of events that takes place from one cell division to the next. PAGE 4 1. 2. It takes different cells different amounts of time to complete a cell cycle Some cells constantly repeat the cycle a. example: Red blood cells Skin cells PAGE 4 Cell growth DNA (chromosomes) are duplicated Cell prepares for division Cell Division Responsible for: 1.Growth 2.Repair 3.Replacement 4.Reproduction PAGE 5 1. Mitosis a. Part of a larger cell cycle b. Occurs in the nucleus of eukaryotic cells c. Responsible for growth and repair, replacement. d. Replaces the entire lining of the small intestine 1)Liver cells only divide for repairing 2) Nerve cells do not divide 3) New cells arise by division of existing cells; Resulting cell is capable to divide again Mitosis Notes Cell division occurs in a series of stages or phases PAGE 6 Preparation for mitosis: Interphase genetic not a part of mitosis material is (doubled)duplicated. Nucleus PAGE 6 CELL MEMBRANE Cytoplasm Animal Cell PAGE 6 Plant Cell Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm 1. Prophase Mitosis begins nuclear envelope disappears chromosome pairs appear and spindle fibers form between the poles Prophase Centrioles PAGE 6 Spindle fibers Animal Cell Plant Cell Spindle fibers Centrioles Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm 2. Metaphase Chromosome pairs line up in the middle of the cell Chromosomes attach to the spindle fibers PAGE 6 Metaphase Centrioles PAGE 6 Spindle fibers Animal Cell Plant Cell Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm 3. Anaphase Chromosomes separate & are pulled to opposite ends of the cell Anaphase Centrioles PAGE 6 Spindle fibers Animal Cell Plant Cell Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm 4. Telophase nuclear envelope forms again chromosomes begin to separate begin to see two cells mitosis ends Telophase Nuclei Chromatin Nuclei Animal Cell Plant Cell Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm Cytokinesis moves inward ( cell) to create cells each cell has its own with nuclei Cytokinesis (animal cell) Cytokinesis:Pinching In ANIMAL CELLS Cytokinesis cell forms in the middle of the cell ( cell) each cell has its own with nuclei Cytokinesis (plant cell) Cytokinesis: Cell plate ANIMAL CELLS Pink Mice Are Totally Cute http://www.cellsalive.com/mitosis.htm http://www.biology.arizona.edu/cell_bio/tuto rials/cell_cycle/MitosisFlash.html Mitosis in Plants Animal Mitosis -- Review Interphase Prophase Metaphase Anaphase Telophase Interphase Plant Mitosis -- Review Interphase Metaphase Telophase Prophase Anaphase Interphase 2. Meiosis a. Cell divides twice to become a gamete (sex cell) b. Will not divide any further until fertilization. E. There are two types of reproduction among living organisms. PAGE 8 1. Asexual Reproduction – a new organism is produced from one organism. a. The new organism has hereditary material identical to the parent. PAGE 8 Name of organism Type of Asexual Reproduction potato budding Strawberry plant runners Hydra budding Sea star, planaria, sponges regeneration PAGE 8 F. Sexual Reproduction 1. Two sex cells join to form a zygote, which will develop into a new organism that is not identical to the parents. a. There are two types of sex cells. Page 9 1. Sperm are made in the male reproductive organs, called the testes. Sperm 2. Eggs are made in the female reproductive organs called the ovaries. Page 9 Eggs 3. Sperm + Egg zygote This is called fertilization. + haploid + 23 + Page 9 haploid = 23 = diploid 46 Cells Body Diploid 46 chromosomes Page 10 Sex Haploid 23 chromosomes Meiosis allows the creation of unique individuals through sexual reproduction. 2. Meiosis – produces four haploid sex cells from one diploid cell, this makes sure that offspring will have the same number of chromosomes as the parent organisms. Page 10 3.What is the difference between diploid & haploid? a. diploid – cell whose similar chromosomes occur in pairs (2n) b. haploid – cell that has half (n) the number of chromosomes as body cells. Page 10 Draw this table in your notes on the bottom of page 10. 46 Chromosomes (diploid) 23 Chromosomes (haploid) Heart Cell Muscle Cell Stomach Cell Liver Cell Egg Cell Skin Cell Sperm Cell Page 10 Let’s Practice! Organism Diploid Number Haploid Number Mouse 40 20 Chicken 78 39 Tomato 24 12 Housefly 12 6 Human 46 23 Page 11 What is DNA? Deoxyribonucleic Acid Contains the genetic information: located in the nucleus Twisted ladder Shape of it is a double helix: looks like a spiral staircase DNA is made up of many repeating units called nucleotides Phosphate group 5 carbon sugar Nitrogenous Base DNA Structure – Watson and Crick (1953) Rosalind Franklin X-Ray photo of DNA (1952) (Deoxyribonucleic Acid) What is a nucleotide? 1. 2. 3. Sugar (5 carbon) Phosphate group Nitrogenous base (there are four bases) Cytosine C T Adenine A Guanine G Thymine Each base has a compliment. That means that it normally bonds with another base. For example: A always bonds with T C always bonds with G Phosphate group A T 5 carbon sugar Hydrogen bond T A C G G C Nitrogenous base nucleotide Let’s Practice T- A C- G G- C A- T A- T T- A T- A G- C C- G C- G Original Strand Complimentary Strand C- G G- C T- A C- G T- A A- T A- T T- A G- C G- C C- G T- A Chromosome Number Transcription Translation DNA RNA Protein Trait RNA processing Making Proteins Step 1: DNA replication Step 2: RNA synthesis (Using a piece of DNA to make RNA, called transcription) Step 3: Amino acids form proteins (called translation) DNA RNA Protein RNA Is single-stranded Contains the sugar ribose Has the base U (uracil) instead of T (thymine) There are 3 types: mRNA – messenger RNA rRNA – ribosomal RNA tRNA – transfer RNA Making a protein from the plans in the DNA is a two step process. Transcription: A messenger RNA copy of the gene is made. Translation: The mRNA is sent to a ribosome where a protein is made.