Biology SOL Review
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Transcript of Biology SOL Review
Biology SOL ReviewA 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
CarbohydratesMonosaccharides
• Builds carb molecules• Used by cells for energy• C-H-O in a 1:2:1 ratio• Ex: Glucose C6H12O6
Disaccharides• 2 Monosaccharidesbonded 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
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 CellPlant 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 FunctionNucleus (like the Brain) Controls Functions; DNA is
hereCytoplasm (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 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
• 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
CO2 + H2O + Sunlight C6H12O6 + O2
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
O2 + C6H12O6 H2O + CO2 + 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 RecessiveDominant Genes
• Produces the Dominant Phenotype whether it’s 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 Eyed50% 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 DNA’s 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 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• 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 KeysSystem 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…
BacteriaEubacteria
• 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 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• 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 AngiospermsAngiosperms
• 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. Photosynthesis2. Transpiration: Loss of water through leaves3. 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
CO2 + H2O → C6H12O6 + O2
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 Herbivores Carnivores Top Carnivores
Symbiotic RelationshipsMutualism Commensalism Parasitism
Both organisms benefit
1 organism benefits but 1 organism is
neither harmed nor benefits
1 organism benefits but 1 organism is
harmed
SuccessionPredictable 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 ConceptsNiche
• 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 VariablesIndependent 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!