Biology review

What You Need to Know for the EOC

1.) Life Chemistry

 pH is the measure of how acidic or basic something is.

 Anything that has a pH of 1 to 6.9 is an acid

 Anything with a pH of 7 is neutral

 Anything with a pH of 7.1 to 14 is a base.

 Remember: Another name for an Enzyme is a Catalyst!

 BUFFERS: Compounds that maintain homeostasis by regulating pH levels (ie:

keep pH at whatever level it needs to be at)! Keep pH at whatever level is best

for the organism, whether it’s acidic, basic, or neutral.

a. Example: If we have a buffer of pH of 7, no matter how much acid we add, the

pH of the buffer will remain at 7!

2.) Water

 Water moves by osmosis across membranes.

 Osmosis is the movement of water from an area of high concentration to an area of

low concentration through a selectively permeable membrane.

 Osmosis is a form of PASSIVE TRANSPORT meaning it does NOT require energy.

 Remember: SALT and SUGAR SUCK! Water will always follow salt or sugar

into or out of things.

3.) Transport

 Passive Transport – the movement of particles with their concentration gradient (from

high concentration to low concentration) and does NOT require energy.

 Examples of passive transport: diffusion, facilitated diffusion and

osmosis.

o Examples of Diffusion:

 Spraying perfume/axe body spray that spreads through a room

 Diffusion of particles (water and other molecules through cell

membrane)

 Diffusion of oxygen through the skin of amphibians.

o Examples of Osmosis

 Shriveling up of a slug when salt is poured on it, or the shriveling of a

fresh water plant put into salt water.

o If there is more salt or sugar outside of the cell, water will move

OUT of the cell and the cell will shrivel up and die

(SALT/SUGAR SUCKS!)

o Doesn’t use energy!

 A cell placed in freshwater will swell up, or the gummy bear placed in

freshwater that got HUGE!

o If there is more salt INSIDE of the cell than outside of the cell,

water will move in, and the cell will swell.

What You Need to Know for the EOC

o Doesn’t use energy!

o Remember: Water moves, salt/sugar does NOT!

o Facilitated Diffusion – passive transport using proteins in the plasma

membrane.

 Active Transport – the movement of particles AGAINST their concentration gradient

(from low concentration to high) that REQUIRES energy.

o Example: Sodium/Potassium Pumps in the plasma membrane

4.) Organic Molecules

 Polymers - large chains made up of smaller subunits called monomers.

 Carbohydrates (polymer):

 Subunit (monomer) – monosaccharide (simple sugars)

 Function – to store energy (short term energy storage, to be used for

energy right away)

 Examples – cellulose (makes up plant cell wall), starches (bread, pasta),

and glycogen.

 Lipids (polymer):

 Subunit (monomer) – triglyceride (glycerol and three fatty acid tails)

 Function – stores energy (long term energy storage), protective

coverings, insulation.

 Examples – plasma membrane, fats, oils, and waxes

 Proteins (polymer):

 Subunit (monomer) – amino acids

 Function – enzymes, transport, cell signaling.

 Examples – enzymes!

 Nucleic Acids (polymer):

 Subunit (monomer) – nucleotides

 Function – to store genetic information

 Examples – DNA and RNA

 Enzymes – a protein that speeds up the rate of a chemical reaction.

 AKA a catalyst

 DENATURED with high temperatures or changes in pH’s.

o Denature – the process by which proteins lose their shape due to high

temperatures or low pH’s. Changes the shape of the enzyme (lock) and

therefore the substrate (key) can no longer fit into the active site of the

enzyme.

 Hormones – long distance chemical messengers. Promote growth and

development (think puberty).

5.) Cells

 Prokaryotes – PRO means NO! Prokaryotes have NO membrane bound

organelles.

What You Need to Know for the EOC

 Remember: Prokaryotes can have ribosomes to make proteins.

 Very simple

 No nucleus just DNA in the cell

 THE ONLY PROKARYOTE KINGDOM IS BACTERIA

 Have a plasmid: Small circular piece of DNA that controls genes for

antibiotic resistance.

 Eukaryotes – Have membrane bound organelles.

5A) Stem Cells

 Stem cells are cells that are NOT specialized. This means that they do NOT have a

specific function or job yet.

 Adult cells become differentiated around Day 14. Differentiation means

that cells are given specific jobs (ie: heart cell, liver cell, skin cell, hair

cell, etc).

 Because stem cells are NOT differentiated, they have the potential to

become ANY kind of cell.

 Remember, all cells contain the SAME amount and type of DNA.

Depending on what environments cells are placed in determines what

kind of cell they will become!

 There are two types of stem cells: embryonic and adult. Embryonic stem

cells are those cells that have yet to differentiate into their specialized cell

type. Adult stem cells are those cells that remain non-specialized in

adults (ie: in the bone marrow)

 Benefits of stem cells: could cure diseases such as leukemia,

Alzheimers, cancer, etc. by replacing diseased cells with healthy cells.

 Ethical Issues: Should we use stem cells to cure disease?

6.) The Organelles

 Plasma Membrane: Maintains Homeostasis by allowing some things to enter the

cell while keeping other things out of the cell (selectively permeable)

o Plasma Membrane Structure: The plasma membrane is made of the

following:

 Phospholipid - (hydrophilic/water loving heads and

hydrophobic/water fearing tails.

 Cholesterol – provides stability to the membrane

 Channel and Carrier Proteins – used to transport particles across the

plasma membrane that cannot enter by diffusion/osmosis.

What You Need to Know for the EOC

 Nucleus: Contains DNA; control center of the cell

 Ribosomes: Makes protein

 Looks like little tiny black dots in the picture of a cell.

 FOUND IN BOTH PROKARYOTES AND EUKARYOTIC CELLS

 Mitochondria: Break down sugars (glucose in foods) to release energy

 Has many folds (Cristae) in order to increase surface area and release

more energy.

 Chloroplast: Uses energy from the sun to create simple sugars.

 Found in plants, bacteria, and algae

 Vacuole: acts as a storage center

 Large central vacuole in plant cells

 Cell Wall: provides structure and support for the cell.

 Can be found in bacteria (made of cellulose), plants (made of

cellulose) and fungi (made of chitin).

7.) Photosynthesis

What You Need to Know for the EOC

 Equation: Carbon Dioxide (CO2) + Water (H2O) + Energy (Sun)  Sugar (C6H12O6)

+ Oxygen (O2)

 Reactants (what goes in): Carbon Dioxide (CO2), Water (H20), and Energy (sun)

 Products (what comes out): Sugar (C6H12O6) and Oxygen (O2)

 Organelle: Chloroplast!

 Organisms that photosynthesize: some bacteria, plants, and algae

 Factors that affect the RATE of photosynthesis: amount of sunlight, amount of water,

amount of CO2

8.) Cellular Respiration (a.k.a aerobic respiration)

 Equation: Sugar (C6H12O6) + Oxygen (O2)  Carbon Dioxide (CO2) + Water (H2O)

+ Energy (ATP)

 Remember the other name for energy is ATP!

 Reactants (what goes in): Sugar (C6H12O6) and Oxygen (O2)

 Products (what comes out): Water (H2O) + Carbon Dioxide (CO2) + Energy (ATP)

 Organelle: Mitochondria

 Organisms go through C.R.: All Eukaryotes (all organisms except for Bacteria!)

 Folds inside the mitochondria INCREASE SURFACE AREA for the reaction to

happen

9.) Anaerobic Processes (a.k.a Fermentation):

 Anaerobic – a process that does NOT require oxygen.

 Aerobic – a process that does use oxygen.

 Anaerobic respiration occurs when cells run out of oxygen but still need energy.

 Occurs in the CYTOPLASM, not in the Mitochondria. Only aerobic respiration

occurs in the Mitochondria.

 Anaerobic Respiration (Fermentation) does NOT make much ATP! Aerobic/Cell

Respiration makes MUCH MORE ATP per sugar molecule.

 Two processes:

 Lactic Acid Fermentation: cells make energy in the absence of oxygen and

causes the muscle burn felt during exercise.

 Alcoholic Fermentation: the processes by which bacteria and yeast create ethyl

alcohol and carbon dioxide in the absence of oxygen. Makes bread rise, and

alcoholic beverages.

10.) The Cell Cycle

 The cell cycle consists of two parts: Interphase and Mitosis/Meiosis

 Interphase is the LONGEST part of the cell cycle, and is the stage in which the cell

carries out normal functions such as metabolism, DNA replication, growth, etc.

 Interphase consists of THREE separate phases:

 G1 phase: Cell grows in size and prepares for DNA division.

What You Need to Know for the EOC

 S phase: DNA/Chromosomes are replicated. Organelles are also

replicated at this time.

 G2 phase: Cell continues to grow in size and prepares for division.

 After a cell goes through interphase (G1, S, G2), it goes through either mitosis or

meiosis depending on the type of cell that it is.

 When cells escape the regulations of the cell cycle, they become cancerous.

11.) Mitosis

 Asexual reproduction

 One cell makes TWO IDENTICAL daughter cells.

 All cells with the exception of sperm and egg go through mitosis.

 Cells are diploid. One diploid cell makes two more diploid cells.

 Cells are IDENTICAL!

 If a cell has 46 chromosomes and goes through mitosis, the resulting daughter cells

will have 46 chromosomes.

 Process begins with interphase (longest phase) of the cell cycle, then the cell enter

mitosis.

 Steps of Mitosis: prophase, metaphase, anaphase, telophase, and cytokinesis.

 Cancer – cells divide without control!

12.) Meiosis

 CAUSES GENETIC VARIATION!

 Sexual Reproduction

 One cell makes FOUR DIFFERENT cells.

 Only sperm and egg go through this process.

 The cells produced are haploid. One diploid cell makes FOUR HAPLOID cells.

 If a cell has 46 chromosomes and goes through meiosis, the resulting daughter

cells will have 23 chromosomes.

 Cells are DIFFERENT than their parent cell.

 Processes that cause variation:

 Crossing Over – Chromosomes swap part of their chromosome in

Meiosis.

What You Need to Know for the EOC

 Nondisjunction – chromosomes do NOT separate properly during

meiosis. Causes Trisomy 21 (Down Syndrome!)

 Recombination of Alleles – genes are arranged in different combinations.

 Fertilization – joining of sperm and egg adds to the genetic variation of

the offspring.

13.) DNA Replication

 Makes new DNA (DNA  DNA)

 Has to happen before cell division (during the S-phase of interphase) so that each

new cell gets a copy of DNA.

 Structure: Double Helix

 3 Dimensional shape determined by Watson and Crick.

 Complimentary Base Pairing Rules:

 A  T, C  G, T  A, G  C

 Nucleotide Structure:

 A phosphate group

 A simple sugar (deoxyribose)

 Nitrogenous Bases (A, T, C, G)

 DNA base pairs are held together by WEAK hydrogen bonds. This ensures that

DNA strands can separate during replication and transcription!

 Mutations:

 Substitution Mutation: a change in a single base pair. Can change entire

protein or just one amino acid.

 Addition or Deletion Mutation: deletion or insertion of a base pair.

Changes the entire reading frame and protein structure.

 Chromosomal Alteration: change in an entire chromosome. Causes

Trisomy 21 aka Down syndrome!

14.) DNA Transcription

 Makes a RNA transcript from a DNA strand (DNA  mRNA).

 Three types of RNA

 mRNA – takes the chemical message in DNA to the ribosome.

 tRNA – transfers amino acid to the ribosome for protein assembly.

 rRNA – RNA that makes up the ribosome.

 Structure: single strand

 Complimentary Base Pairing Rules:

 A  U, T  A, C  G, G  C

 Remember, there is no T in RNA!!

 Nucleotide Structure:

 Phosphate Group

 Simple Sugar (ribose)

 Nitrogen Base Pairs (A, U, C, and G)

What You Need to Know for the EOC

 Codon – group of three RNA base pairs.

 Anticodon – a group of three base pairs found on a tRNA molecule that matches up

with the mRNA codon.

15.) RNA Translation

 Process by which mRNA is turned into a protein (mRNA  Protein)

 Happens in the ribosome.

 Started by the Methionine codon (AUG)

 mRNA codons are turned into a sequence of proteins using the a CODON TABLE!

Remember that when you use the codon table, you have to use an mRNA

sequence! If the EOC gives you DNA, convert it to mRNA. If the EOC gives you

tRNA, convert it to mRNA!

 Proteins are held together by peptide bonds.

16.) Genetics

 Gregor Mendel: the father of genetics; studied plants in peas

 Study of how traits are passed from parents to children.

 Genotype: the genetic make-up of an organism (HH, Hh, hh)

 Phenotype: how something looks (brown hair, short, sickle cell)

 Homozygote: have two of the same size leter (HH or hh)

 Heterozygote: have different size letter (Hh)

 Dominant: masks a recessive trait

 Recessive: masked by a dominant trait

 Punnett Squares: used to predict the outcome of a mating

 Co-Dominance – when both parental phenotypes are shown in the offspring

 Ex: Red Cow X White Cow = Roan Cow (Red/White Spotted Cow)

 Incomplete Dominance – the two parental phenotypes blend together and a new

third phenotype is produced.

 Ex: Red Flower X White Flower = Pink Flower

17.) Genetic Diseases

 There is one DOMINANT genetic disease

 Huntington’s Disease: doesn’t show up until around ages 30 to 50.

Slow deterioration of the brain.

 There is NO such thing as a carrier for a dominant genetic disease.

 There are four RECESSIVE genetic disease

 PKU: recessive disorder characterized by the inability to break down

the amino acid phenylalanine. Common in Caucasian people. Can be

cured through dietary restricts (ie. not eating foods with

phenylalanine).

 CF: recessive disorder characterized by a build-up of mucous in the

lungs.

What You Need to Know for the EOC

 Tay-Sachs: recessive disorder characterized by the build-up of lipids

in the brain. Common in people of Jewish ancestry.

 Sickle-Cell Anemia: recessive disorder characterized by sickle

shaped red blood cells. Lowers the ability for the body to carry

oxygen. Common in people of African descent.

 There are two SEX – LINKED RECESSIVE disease

 ALWAYS USE X AND Y’S IN THESE PUNNET SQUARES!

 Although sex-linked, the disorders are still RECESSIVE. To have the

disease as a female you need TWO little letters on the X sex

chromosome. Men only need one little letter on their X sex

chromosome to have the disease.

 Men can NEVER be carriers for x-linked diseases.

 Color – Blindness: a x-linked recessive disease characterized by the

inability to distinguish the colors red and green. Mainly effects males.

 Hemophilia: a x-linked recessive disease characterized by the

inability to form blood clots. Mainly effects males.

 There is one Chromosomal Alteration disease

 Trisomy 21 – Down syndrome. Caused by non-disjunction in

meiosis.

18.) Blood Types

 There are four blood types.

 Human Blood types are an example of MULTIPLE ALLELES and Co-Dominance

in humans!

 ALWAYS USE THE I’S FOR BLOOD TYPE PUNNETT SQUARES

 There phenotypes: A, B, AB, and O

 There are four genotypes

 A: IAIA (homozygous); IAi (heterozygous)

 B: IBIB (homozygous); IBi (heterozygous)

 AB: IAIB (co-dominant)

 O: ii (recessive

19.) Pedigrees

 Family tree that shows the inheritance of certain traits.

 Males are squares and Females are circles

 Dominant trait pedigrees have a lot of people shaded in. Someone in each

generation is shaded in.

 Recessive pedigrees do not have a lot of people shaded in. Usually there are two

parents that do not have the disease but they have a child that does. Look for the

disease skipping generations! Or for two carriers that have a child with the

condition.

What You Need to Know for the EOC

 Sex-Linked pedigree usually have mostly squares (men) shaded. X-linked

pedigrees can have women shaded in but it should be overwhelmingly men shaded

in.

20.) Genetic Technology

 Recombinant DNA – insertion of DNA from one species into the DNA of another

species.

 Transgenic organism – organisms that contain recombinant DNA. Organisms that

have DNA from two different species in the one organism.

o Transgenic organisms have been used to clean up oil spills, create human

insulin, create antibiotics, produce dye, medicines, etc.

 Gel Electrophoresis – the process by which DNA is separated based on size. Can

determine paternity, who committed crimes, etc.

 If the bands match up, you can figure out the suspect.

 Creates unique DNA fingerprints for each person. Could be used in

forensic science.

 Gene Therapy – the insertion of a normal gene into a mutated one in order to cure a

genetic disease.

 Human Genome Project – the project that sequenced the base pairs of the entire

human genome. Helped diagnose and cure many genetic diseases.

 Restriction Enzymes – little DNA scissors. Cut genes at specific base pairs.

 Plasmids – small circular pieces of DNA in bacteria. Used as vectors to insert new

genes into various organisms.

o Example: Using bacterial plasmids to make insulin. We take the HUMAN

GENE for insulin and cut it out using restriction enzymes. We then insert

that human gene into a bacterial plasmid. The bacterial plasmid turns that

gene into the protein insulin. Then we harvest the insulin and use it in

patients with diabetes!

 Test Cross – crossing an organism with an unknown genotype with a known one

(usually homozygous recessive) in order to determine the genotype of the

unknown.

 Artificial Selection – the choosing of specific traits by humans in order to create

genetically superior organisms.

21.) Change through Time

 Theory of the First Cell:

o Oparin’s Theory: The first cell was created in the ocean through the

combination of monosaccharides, amino acids, tri-glycerides, and

nucleotides into complex organic molecules.

o Miller and Urey: Proved Oparin’s hypothesis through experimentation

What You Need to Know for the EOC

o Evolution of the first cell: Anaerobic Prokaryote, Photosynthesizing

Prokaryote, Aerobic Prokaryote, First Eukaryote, Plants.

 Charles Darwin – Founder of Evolutionary Theory

 Survival of the Fittest: organisms that are best adapted to their environment are the

organisms that will survive to pass on their traits to their offspring.

 Mimicry – copying the appearance of another species in order to receive some

evolutionary advantage.

 Camouflage – blending in with the environment

 Vestigial Structure – a structure that once had a function but no longer serves a

purpose.

 Ex: Whales having a pelvic bone.

 Ex: Humans and wisdom teeth.

 Homologous Structure: common ancestor, evolved into different functions.

 Analogous Structure: doesn’t have a common ancestor but has the same function.

 Geographic Isolation: Species being to look different because they are separated

by geography (ie: canyons, mountains, rivers, etc).

 Reproductive Isolation: Species can physically not mate and make viable

offspring.

 Divergent Evolution: one species becomes two

 Convergent Evolution: two different species begin to look like one.

 Adaptive Radiation: the evolution of one species into many species in order to fit

their specific environment.

 Example: Bird Beaks!

 Dichotomous Key: Know how to read one

 Cladogram: organisms that are close to each other on a cladogram are closely

related; organisms that are far apart are less closely related.

 Antibiotic and Pesticide Resistance: Some bacteria and pests have a genetic

advantage because they are resistant to antibiotics or pesticides. This causes the

formation of “super bugs” or bacteria/pests that are resistant to the treatments we

have available.

22.) Taxonomy and Classification

 Taxonomic rankings have changed as more information has been added to the

classification system.

 The Linnaean system is more accurate than the Aristotle system because

Linnaeus’s system allows for organisms to be added as the species continues

evolving.

 Groups organisms based on EVOLUTIONARY SIMILARITIES

 Taxonomic ranking system: Kingdom, Phylum, Class, Order, Family, Genus,

Species

 Binomial nomenclature: two word naming system. Uses genus and species

What You Need to Know for the EOC

23.) The Six Kingdoms

 Archaebacteria and Eubacteria: oldest organisms

 Archaebacteria live in extreme environments and eubacteria are the

everyday (run of the mill) bacteria.

 Prokaryotes, single cell

 Can be both autotrophs and heterotrophs

 Can reproduce through binary fission (asexual) or conjugation

(sexual).

 Have flagella for movement and cilia for attachment

 Protists

 Always eukaryotic

 Can be single celled or multi cellular

 Can be autotrophs or heterotrophs

 Euglena: can both photosynthesize and go through cellular

respiration, have both chloroplast and mitochondria.

 Phototaxis: Movement of organisms towards light.

 Chemotaxis: Movement of organisms based on chemical cues.

 Contractile Vacuole: Regulate the amount of water in protists.

 Photoreceptor: Simple form of an eye in a protist. Aids in phototaxis.

 Pseudopodia: “Fake Feet” in amoebas that aid in endocytosis

(movement of particles into the cell body)

 Fungus

 Always eukaryotic, multicellular, and decomposers (heterotrophs)

 Have a cell wall made of chitin

 Can reproduce sexually through spores or a-sexually through budding

and fragmentation.

 Plants

 Always eukaryotic, multicellular, and autotrophs.

 Animals

 Always eukaryotic, multicellular, and heterotrophs.

24.) Plants

 Xylem transports water and Phloem transports sugars

 Cuticle: waxy layer that protects plants from drying out.

 Angiosperm: flowering plants. Produce fruits!

 Gymnosperms: plants with pine needles and pine cones. Do NOT produce fruit.

What You Need to Know for the EOC

 Pollination: occurs when pollen (sperm) unites with eggs in flower.

 Have a cell wall made of cellulose.

 Stomata: pores in plants that allow for the exchange of gasses.

 Guard Cells: control the opening and closing of stomata.

 Transpiration: loss of water through the stomata (plant sweating).

 Phototropism: tendency of plants to move toward light.

 Gravotropism: tendency of plants to put their roots down towards the ground.

 Thigmotropism: tendency of plants to respond to touch (venus fly trap)

 Seeds: have food source, water, and embryo. Can withstand tough environments.

 Order of plant evolution: Non-Vascular Plants (liverwarts and hornwarts),

Vascular Non-Seed Plants (mosses and ferns, Vascular Seed plants (gymnosperms

and angiosperms)

25.) Animal Behavior

 Innate = inherited = born with the behavior.

o Example: Baby sea turtles following the moonlight to the ocean

o Migration: Seasonal movements of animals based on external cues such as

light, temperature, etc.

o Estivation: A state of lowered metabolic rate (“sleeping”) during extreme

heat (summer).

o Hibernation: A state of lowered metabolic rate (“sleeping”) during the

winter

o Social Behaviors:

 Courtship Behavior: behaviors carried out before mating

 Bee’s Social Dance: Bees can direct others to the location of

nectar/honey, etc

o Pheromone – scent used to communicate between organisms.

 Learned behaviors – a behavior that is learned.

o Imprinting – forming a social attachment at a young age.

 Ducks forming an attachment to a person.

o Habituation – a habit that becomes ignored over time.

 Ignoring school bells during third period.

o Classical Conditioning – associating a certain stimulus with a response.

 Pavlov and the dog

o Trial and Error – trying something over and over until getting a desired

reweard.

26.) Human Health

 Vaccine – prevents disease by mounting an immune response to the weakened

virus in the vaccine.

What You Need to Know for the EOC

 HIV – virus that causes AIDS. Weakens the immune system. Very hard to cure

because it is an RNA virus, and it mutates very quickly.

 Virus – neither dead nor alive. Has to have a cell to replicate in.

 Innate Immunity – immunity that you are born with (T cells and B cells)

 Acquired Immunity – immunity acquired through vaccinations, breast milk, etc.

 T cells – directly attack foreign invaders.

 B cells – make proteins that attack foreign invaders.

27.) Viruses

 Small micro organisms composed of a genome (either DNA or RNA) surrounded

by a protein coat (capsid), and sometimes by an envelope.

 Lytic Cycle – Viral replication cycle in which the virus immediately begins

infecting and destroying cells.

 Lysogenic Cycle – Viral replication cycle in which the virus incorporates itself into

the host DNA. After a period of time, the virus begins infecting and destroying the

host cell.

 Retroviruses: Viruses with an RNA genome that needs to be converted to a DNA

genome.

 HIV is a Retrovirus!

 Hard to find a cure for HIV because the virus mutates quickly!

 Reverse Transcriptase: Enzyme that converts RNA  DNA

28.) Ecology

 Heterotrophs – organisms that consume other organisms.

 Herbivores, Carnivores, Omnivores, Scavengers, Decomposers.

 Autotrophs – organisms that make their own food.

 Plants, algae, and some bacteria.

 Symbiosis – a permanent relationship between two organisms.

o Mutualism – a relationship between two organisms in which both organisms

benefit.

o Parasitism – a relationship between two organisms in which one benefits at

the expense of another organism.

o Commensalism – a relationship in which one organism benefits and the

other organism is neither harmed nor benefited.

 Know how water, carbon, and nitrogen is cycled throughout the environment.

 Know how to read a food chain. Food chain is a simplistic version of energy flow.

 Energy flow is showed using arrows from the organism being eaten to

the organism eating it.

 Know how to read a food web. Shows all possible feeding relationships.

What You Need to Know for the EOC

 Know the trophic levels (primary producer, primary consumer, secondary

consumer, tertiary consumer, and quaternary producer).

 Primary producers have the MOST energy available.

 As you lose energy you move up the trophic pyramid.

 Limiting Factor – something that limits an organism’s ability to survive in its

environment.

 Carrying Capacity – the number of organisms that an environment can support

indefinitely.

 J-Curve – A curve of a population that grows without limit.

 S-Curve – A curve that levels off when the carrying capacity is reached.

 Age Structures – double sided bar graphs that show the age, gender, and percent of

population.

 Stable, rapid, and slow growth.

 Know how predator verses prey relationships work.

 Biotic Factors – factors that are alive (animals, moss, grass, etc).

 Abiotic Factors – factors that are not alive in an environment (rocks, water, etc)

 Niche – the role an organism plays in its environment.

 Habitat – where an organism lives.

 The most common loss of biodiversity is habitat loss!

 Habitat loss caused by acid rain, deforestation, pollution, etc.

 Global Warming – the increase in temperature due to the increase in carbon

dioxide gas in the atmosphere.