Biology SOL Review A General Overview Created by Rhonda Taylor, Menchville High School 2014 Water: Polarity Caused by unequal sharing of electrons H end is more positively charged & O end is more negatively charged Causes water to be a good solvent (dissolver) Creates Hydrogen bonds Water: Hydrogen Bonds Attraction between the positive H of one water molecules & the negative O of another water molecule Weak bond Breaks & reforms easily Other Water Properties Cohesion water bonds to water Adhesion water bonds to other Neutral pH of 7 Surface Tension cohesion, adhesion & H bonds resistance to breakage High Heat Capacity absorbs a lot of heat before getting hot & takes a long time to lose heat pH Scale Shows how Acidic or Basic (Alkaline) something is Acids: pH 0 6.9 Bases: pH 7.1 14 Neutral: pH 7 Carbohydrates Monosaccharides Builds carb molecules Used by cells for energy C-H-O in a 1:2:1 ratio Ex: Glucose C 6 H 12 O 6 Disaccharides 2 Monosaccharides bonded together Ex: Sucrose (table sugar) (glucose + fructose) Polysaccharides 3+ monosaccharides bonded together Used for long term storage of carbs Ex: Starch (plants) & Glycogen (animals) Lipids Fatty Acids are the building blocks Examples: Phospholipids, Cholesterol, Fats, Waxes & Oils Used by the body for: Long Term Energy Storage Building Cell Membrane InsulationLubrication Proteins Made from 20 different Amino Acids Functions: -Enzymes - speed up chemical reactions -Fight Disease (antibodies) -Build Structures (muscles, hemoglobin) Polypeptides many amino acids bonded together = a Protein Molecule Nucleic Acids Nucleotides are the building blocks Examples include: DNA & RNA Carry genetic code and code for building proteins Cells & Processes Prokaryotes vs. Eukaryotes Pro no! (Prokaryotic Cells do NOT have a nucleus) Smaller in size, more primitive, EX: Bacteria Eu do! (Eukaryotic Cells DO have a nucleus) Generally larger in size, & contain complex membrane bound organelles, EX: Plant, Animal, Fungi & Protist Cells Plant Cell vs. Animal Cell Plant Cells Eukaryotic Boxy Shape Have a Cell Wall Have Chloroplasts Have Chlorophyll 1 Large Vacuole NO Centrioles Animal Cells Eukaryotic Rounder Shape NO Cell Wall NO Chloroplasts NO Chlorophyll 1 or more smaller Vacuoles Have Centrioles Cell Organelles Cell OrganelleFunction Nucleus (like the Brain)Controls Functions; DNA is here Cytoplasm (Jelly Like Fluid)Organelles found floating around in this; Chemical Reactions happen here Mitochondria (Powerhouse)Creates ATP; Site of Cell Respiration Ribsomes (Little Dots)Site of Protein Synthesis; Made of rRNA Chloroplast (Green)Site of Photosynthesis Cell MembraneRegulates what enters & leaves Cell WallRigid outer structure for support & protection Cell Membrane Semi-permeable Phospholipid Bilayer Protein Channels Regulates the materials that enter and exit the cell Diffusion and Osmosis occur thru Diffusion Movement of substances (sugar, salt, ions, oxygen, amino acids, wastes, etc) through the cell membrane from higher to lower concentration Osmosis The movement of water through a semi-permeable membrane from higher water concentration to lower water concentration. Importance to Living Things: Carries nutrient rich liquid into cells Balances pressure & concentration Helps expel wastes Needed by plants to absorb water from soil Photosynthesis Carried out by plants, some varieties of protists and some types of bacteria Occurs in the chloroplasts Chlorophyll is green pigment that traps light energy CO 2 + H 2 O + Sunlight C 6 H 12 O 6 + O 2 Cellular Respiration Carried out by all living things Occurs in the Mitochondria ATP is created which is the energy molecule used by cells to do work O 2 + C 6 H 12 O 6 H 2 O + CO 2 + ATP (energy) DNA DNA vs RNA Deoxyribose sugar Thymine Double Strand Double Helix Contains code for building Proteins Found in the nucleus Ribose sugar Uracil Single Strand 3 Types: mRNA, rRNA, tRNA Makes copies of proteins DNA Technology Human Genome Project mapping all human genes on each of our 46 chromosomes Detection & prevention of genetic disorders & diseases Advances in Genetic Engineering (insulin, disease resistant fruits & vegetables, medicine) Eugenics the practice of improving the genetics of the human race Cloning producing genetically identical individuals Forensics using DNA evidence for identification purposes Genetics Genes: Dominant vs Recessive Dominant Genes Produces the Dominant Phenotype whether its allele is identical or not. Recessive Genes Will only produce the Recessive Phenotype if both alleles are Recessive. Punnett Squares Possibility for Offspring: Genotypes 50% Bb 50% bb Phenotypes 50% Brown Eyed 50% Green Eyed Cross a Homozygous Recessive Green Eyed Mother with a Heterozygous Brown Eyed Father Protein Synthesis Transcription RNA Polymerase enzyme unzips DNA mRNA makes a copy of the DNA code for building a protein Inside the Nucleus of the cell where DNA is located Translation mRNA takes the DNAs protein code to the Ribosome in the cytoplasm tRNA brings in the Amino Acids to build the Protein Start codons & Stop codons tell the RNA where to begin & end when building a Protein Protein Structure & Function in the Body Involved in virtually all cell functions Each protein has a specific role. Constructed from 20 types of amino acids Have a distinct 3-D shape (Lock & Key Model) If shape is altered (Denatured), it wont function Proteins build many structures in our bodies Evolution Darwin Developed the Theory of Evolution Traveled to Galapagos Islands on HMS Beagle Wrote book: On the Origin of the Species Found evidence for Evolution with Finches/Beaks Natural vs Artificial Selection Natural Selection Gradual process where traits become more or less common in a population based on their usefulness to survival A basic mechanism of evolution, along with mutation, migration and genetic drift Artificial Selection Process where humans purposely breed or engineer certain traits into populations Common Ancestry Common descent could provide a logical basis for classification Common ancestry between organisms of different species arises during speciation Evidence for Evolution Taxonomy Taxa Taxonomy is the science of defining groups of biological organisms on the basis of shared characteristics and giving names to those groups. There are 7 groups or Taxa for classifying organisms. Binomial Nomenclature: Writing a Scientific Name Dichotomous Keys System used to identify organisms by answering questions to narrow down characteristics. Diversity of Life Viruses Nonliving particles Made of a protein coat that surrounds DNA or RNA (nucleic acid) Can only reproduce within Host Cells Lytic Cycle- kills host cell Lysogenic Cycle creates a Prophage by putting viral DNA into the Host cells DNA; Virus stays dormant for years eventually causing disease later Example of a Bacteriophage Virus attacking a Bacteria Cell Bacteria Eubacteria Cell wall with Peptidoglycan Found everywhere very common Examples: E.Coli, Salmonella, Staphylococcus aureus Archaebacteria Cell wall NO Peptidoglycan Live in extreme or harsh environments (high temperatures, sulfur, volcanoes, no oxygen, salt) Examples: Methanogens, Halophiles, Thermophiles Both share common shapes: Coccus, Bacillus, Spirillus Both share common arrangements: diplo, staphylo, strepto Protists Plant-Like, Animal-Like & Fungus-Like Move using pseudopods, flagella or cilia Some dont move at all Some are autotrophs & other heterotrophs Examples: Algae, Amoebas, Diatoms, Dinoflagellates Can cause disease and red tides Fungi Some unicellular = yeast = used in baking Some multicellular = mushroom, mold Decomposers Can cause disease athletes foot, jock itch, ringworm Reproduce Asexually (budding & spores) or Sexually (Gametangium) Mutualistic Symbiotic Relationship with plant roots = Mycorrhiza Fungi Animals General Animal Characteristics All Multicellular All Heterotrophic All are capable of movement at some point Reproduce: Sperm + Egg = Zygote Zygote grows into Blastula & Gastrula Gastrula produces layers: Ectoderm, Mesoderm & Endoderm Layers develop into organ systems Invertebrates No backbone Very Diverse Phyla: -Sponges -Cnidarians Jellyfish & coral -Worms flat, round & segmented -Mollusks octopus, snails, clams -Arthropods crabs, insects, spiders -Echinoderms sand dollars, starfish Vertebrates Backbone Phylum: Chordata Subphylum: Vertebrata Classes: -Jawless Fish, Bony Fish, Cartilaginous Fish -Amphibians -Reptiles -Birds (Aves) -Mammals Adaptations Ectothermic must get heat from environment Endothermic can produce their own body heat Mammary Glands - milk for babies Amniotic Egg has a protective shell Plants General Plant Characteristics All Multicellular Autotrophs (producers) Have Roots, Stems & Leaves Cell Walls made of Cellulose Non-Vascular vs Vascular Non-Vascular No veins (Phloem & Zylem) Low growing plants Likes shady, moist areas Ex: Mosses Vascular Have Veins (Phloem & Xylem) Includes Gymnosperms & Angiosperms Ex: Trees, Grass Gymnosperms vs Angiosperms Angiosperms Cone bearing plants Seeds produced in cones Ex: Pine Tree, Fir Tree Gymnosperms Flower producing plants Seeds produced in a fruit or nut Can be Monocot or Dicot Ex: Squash, Grass, Peanuts 1.Photosynthesis 2.Transpiration: Loss of water through leaves 3.Gas Exchange: take in carbon dioxide and release oxygen through the stomata Processes of a Leaf Chloroplasts contain Chlorophyll, the green pigment that traps light energy Chloroplasts & Photosynthesis Carbon dioxide + water sugar + oxygen light CO 2 + H 2 O C 6 H 12 O 6 + O 2 light Energy Flow Energy flows in one direction Energy on Earth comes from the sun Food Chains & Food Webs show how Energy Flows in an Ecosystem Food Chain Example: Food Web: Arrows show the direction of energy flow. Autotrophs HerbivoresCarnivoresTop Carnivores Symbiotic Relationships Mutualism CommensalismParasitism Both organisms benefit 1 organism benefits but 1 organism is neither harmed nor benefits 1 organism benefits but 1 organism is harmed Succession Predictable changes to a community over time. Primary Succession: Brand new community forms EX: new land created from a lava flow or earthquake Secondary Succession: Community starts over after a natural disaster destroys an existing community Other Ecological Concepts Niche The role an organism plays in its community No two organisms can occupy the same niche Examples: -Oak tree provides habitat -Honey Bees pollinate flowers -Worms provide food for Robins -Termite Queen lays eggs for hive Limiting Factors Controls the growth of organisms Can be Biotic, such as: Predation, Disease, Starvation, Competition Can be Abiotic, such as: Habitat loss, Natural Disasters, Temperature, Drought Populations Carrying Capacity (K) represents the population number of individuals the environment can support J-Curve & S-Curve Graphs Initial Growth, Exponential Growth, Steady State, Decline, Extinction or Absence Scientific Investigation Determining Variables Independent Variable The condition you have control over changing you decide the conditions Dependent Variable The condition that changes as a result of the Independent variable In a data table, the Independent Variable is usually the first column! In a data table, the Dependent Variable is usually the second column! On a graph, the Dependent Variable is on the Y-Axis! On a graph, the Independent Variable is on the X-Axis!