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

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!

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