Biology SOL Review A General Overview Water Polarity

Biology SOL Review A General Overview

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 – p. H 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 • •

p. H Scale • • Shows how Acidic or Basic (Alkaline) something is Acids: p. H 0 – 6. 9 Bases: p. H 7. 1 – 14 Neutral: p. H 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 • Used by the body for: • Examples: Phospholipids, Cholesterol, Fats, Waxes & Oils Long Term Energy Storage Building Cell Membrane Insulation Lubrication

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 Organelle Function 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 r. RNA Chloroplast (Green) Site of Photosynthesis Cell Membrane Regulates what enters & leaves Cell Wall Rigid 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 CO 2 + H 2 O + Sunlight C 6 H 12 O 6 + O 2 • 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

Cellular Respiration O 2 + C 6 H 12 O 6 H 2 O + CO 2 + ATP (energy) • Carried out by all living things • Occurs in the Mitochondria • ATP is created which is the energy molecule used by cells to do work

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: m. RNA, r. RNA, t. RNA • 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 Genes • Will only produce the Recessive Phenotype if both alleles are Recessive. Dominant Genes • Produces the Dominant Phenotype whether it’s allele is identical or not.

Punnett Squares Cross a Homozygous Recessive Green Eyed Mother with a Heterozygous Brown Eyed Father Possibility for Offspring: Genotypes – 50% Bb 50% bb Phenotypes – 50% Brown Eyed 50% Green Eyed

Protein Synthesis

Transcription Inside the Nucleus of the cell where DNA is located • RNA Polymerase enzyme unzips DNA • m. RNA makes a copy of the DNA code for building a protein

Translation • m. RNA takes the DNA’s protein code to the Ribosome in the cytoplasm • t. RNA 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 won’t 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 Artificial Selection • Gradual process where traits become more or less common in a population based on their usefulness to survival • Process where humans purposely breed or engineer certain traits into populations • A basic mechanism of evolution, along with mutation, migration and genetic drift

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 cell’s DNA; Virus stays dormant for years eventually causing disease later

Example of a Bacteriophage Virus attacking a Bacteria Cell…

Bacteria Eubacteria Archaebacteria • Cell wall with Peptidoglycan • Cell wall NO Peptidoglycan • Found everywhere – very • Live in extreme or harsh common environments (high temperatures, sulfur, • Examples: E. Coli, volcanoes, no oxygen, salt) Salmonella, Staphylococcus aureus • 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 don’t 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 grows into Blastula & 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 • Have Veins (Phloem & Xylem) • Includes Gymnosperms & Angiosperms • Ex: Trees, Grass

Gymnosperms vs Angiosperms Gymnosperms • Cone bearing plants • Seeds produced in cones • Ex: Pine Tree, Fir Tree Angiosperms • Flower producing plants • Seeds produced in a fruit or nut • Can be Monocot or Dicot • Ex: Squash, Grass, Peanuts

Processes of a Leaf 1. Photosynthesis 2. Transpiration: Loss of water through leaves 3. Gas Exchange: take in carbon dioxide and release oxygen through the stomata

Chloroplasts & Photosynthesis • Chloroplasts contain Chlorophyll, the green pigment that traps light energy 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 Energy Flows in an Ecosystem Food Chain Example:

Food Web: Arrows show the direction of energy flow. Autotrophs Herbivores Carnivores Top Carnivores

Symbiotic Relationships Mutualism Both organisms benefit Commensalism Parasitism 1 organism benefits but 1 organism is neither harmed nor harmed benefits

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 Limiting Factors • 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 • 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

Scie ntifi c Inv esti gati on

Determining Variables Independent Variable – The condition you have control over changing – you decide the conditions In a data table, the Independent Variable is usually the first column! In a data table, the Dependent Variable is usually the second column! Dependent Variable – The condition that changes as a result of the Independent variable On a graph, the Dependent Variable is on the Y-Axis! On a graph, the Independent Variable is on the X-Axis!