Biology Quick Notes

Safety

  • If one of your answer choices is “tell your instructor or teacher,” that is the RIGHT answer…. ALWAYS!
  • Use common sense. Don’t run, be careful with glass and sharp tools, don’t let clothing and hair hang into a fire, etc.
  • Always wear goggles!!
  • Never put hot glass into cold water. It will break/explode!!
  • Never heat a sealed flask. The pressure will cause the cork and fluid to shoot out!

Lab Equipment

  • Length=meter stick-meters (m, cm, or mm)
  • Mass=triple beam balance-grams (g or kg)
  • Volume=beaker, flask, graduated cylinder-liters (L or mL)
  • Temperature=thermometer-(oC)
  • Looking at something small? Choose a microscope!

Experimental Design

  • Steps of an experiment:
  • Problem
  • Hypothesis
  • Experiment
  • Analysis
  • Conclusion
  • Problem=question
  • Hypothesis=educated guess
  • IF…. THEN statement
  • More specifically, IF… independent variable, THEN…. dependent variable.
  • Experiment
  • Independent variable= what changes; look for the word “different”
  • Dependent varible= what is measured; look for collection of data
  • Control=compare to experimental data to make it more accurate
  • Try putting the word NO in front of your independent variable
  • Ex: IV=fertilizer Control=No fertilizer
  • Constants=things that you keep the same
  • Analysis
  • QuaLitative Data= letters, quality
  • QuaNtitative Data= numbers, quantity
  • Conclusion
  • Summary of findings, restate hypothesis

Graphing

  • Independent Variable on X axis (horizontal); Dependent Variable on Y axis (vertical)
  • Types of graphs
  • Line graph- shows change over time
  • Bar graph- compares similar but separate categories
  • Circle/Pie graph- parts of a whole (percentages!)
  • If there is a chart, graph, or table, you will need to use it to answer the question. They don’t waste space for no reason!
  • Look for patterns in the graphs; ex. add 10, double, etc.

Organization

  • Cell-basic unit of life
  • Cell, Tissue, Organ, Organ System, Organism, Population, Community, Ecosystem, Biosphere
  • A bunch of identical cells =tissue
  • A bunch of different types of cells =organ

Populations

  • Biotic factors=anything living
  • Abiotic factors=anything nonliving
  • Niche=organism’s job or role in ecosystem
  • If two animals share the same niche, competition will result
  • Organisms will compete until one dies or adapts to a new niche
  • Predator vs. Prey
  • Predator= eats the prey
  • Prey= gets eaten by predator
  • Predator increases, prey dies---- Predator decreases, prey reproduces
  • Types of Curves
  • J-curve= Exponential graph; Ideal conditions with unlimited resources and no predators
  • S-curve= Realistic graph; Actual conditions in environment
  • Carrying Capacity
  • Point where S-curve levels off or flattens or when it begins to fluctuate at an even rate
  • Carrying capacity is number of a species that can be supported by the environment
  • If population exceeds carrying capacity, it will decrease until it is below carrying capacity
  • Ways to predict graphs
  • Increase in predators=population decreases
  • Increased birth rate=population increases
  • Increased death rate=population decreases
  • Environment restoration=population increases

Symbiosis

  • Symbiosis-relationship between organisms of different species
  • Parasitism- one benefits and the other is harmed (+/-)
  • Mutualism- both benefit (+/+)
  • Commensalism- one benefits and the other is not harmed or benefitted (+/o)
  • Competition-organisms of the same species challenging each other for resources or an environmental niche (job)

Food Chains/Webs/Pyramids

  • Producer-Makes their own energy/food (Plants)
  • Consumer-Has to eat something to get food/energy (Animals)
  • Herbivore- Eats plants
  • Carnivore- Eats meat or other animals
  • Omnivore- Eats both plants and meat
  • Decomposers-Eat dead stuff
  • Food Chain- A simple line of who eats whom (usually only 3 to 4 links)
  • EX: grass  grasshopper  frog snake
  • Arrows always point to the one GETTING the energy (eating)!!
  • Food Web- A bunch of related food chains (can be very complex!!)
  • Food Pyramids- Show how energy is transferred between trophic levels
  • Energy moves UP the pyramid, never DOWN
  • Trophic level- each feeding level of the pyramid
  • Producers—Produce their own food (ex. plants)
  • Primary Consumers or 1st Order Heterotrophs—Eat producers (ex. Mouse)
  • Secondary Consumers or 2nd Order Heterotrophs—Eat primary consumers (ex. Snake)
  • Tertiary Consumers or 3rd Order Heterotrophs—Eat secondary consumers (ex. Hawk)
  • Rule of 10: Only 10% of the energy moves UP each trophic level. 90% is lost to the environment.
  • Biomass—How much dry weight exists at each level
  • The lowest level on the pyramid has the biggest biomass, because it is is the biggest level. The highest level has the least biomass.
  • Subtract a 0 from the number of calories for each trophic level you move up. Add a 0 if you are moving down the pyramid

Cycles

  • Water Cycle—Water moving through the environment
  • Condensation- Water goes from gas to liquid in clouds
  • Precipitation- Water falls from the sky
  • Lakes, Rivers Streams, Groundwater, Oceans
  • Evaporation-Water goes from liquid to gas back into the sky
  • Transpiration- Water leaves plants as a gas
  • Carbon Cycle—Carbon and oxygen cycling through the environment
  • Plants take in CO2 and release O2(Photosynthesis)
  • Animals take in O2 and release CO2
  • Dead animals become fossils fuels underground after millions of years
  • Burning (wood, gas, or factories) releases carbon into the atmosphere
  • Nitrogen Cycle—Nitrogen cycling through environment
  • Key Player—BACTERIA!!!
  • Nitrogen exists as a diatom, N2, in the atmosphere
  • Nitrogen is converted by soil microbes (bacteria) into nitrates and nitrites for plants to use
  • We get our nitrogen by eating plants

Biochemistry

  • Water- Liquid required for life
  • Cohesion- Water sticks to itself
  • Adhesion- Water sticks to other stuff
  • Surface Tension- light things can stand on it; water makes a “bubble” instead of instantly spilling over
  • Heat Capacity- You can heat it a lot before it boils
  • Biochemicals- Chemicals that make up living things—all contain Carbon
  • Carbohydrates- simple and complex sugars; quickest energy source
  • Lipids- fats; store energy; make up cell membrane
  • Proteins- make up muscles; also carry out cell functions
  • Nucleic Acids- make up DNA and RNA

Cells

  • Basic unit of life
  • All living things have DNA
  • Prokaryotes
  • Bacteria
  • Have NO nucleus or membrane bound organelles
  • Usually have cell wall, cell membrane, cytoplasm, DNA, and ribosomes
  • Eukaryotes
  • Plants and Animals
  • Have a nucleus and lots of membrane bound organelles
  • All have mitochondria
  • Animal Cells
  • Cell Membrane- goes around cell
  • Cytoplasm-Jelly-like fluid inside cell
  • Nucleus- holds DNA
  • Mitochondria- Cellular Respiration; make ATP (cell energy)
  • Ribosomes- Make proteins aka protein synthesis
  • Plant Cells
  • Have all the same organelles as animal cells plus some extras
  • Cell Wall-Provides additional structure to cells; outside of cell membrane; reason why plants can’t move
  • Chloroplasts- Photosynthesis; make sugar; make plant green
  • Large Vacuole- stores large amounts of water and nutrients in plants

Plasma Membrane

  • Protects cells and acts as a boundary between what’s inside and outside the cell
  • Phospholipid Bilayer- two layers of phospholipids
  • Hydrophilic Head- likes water (point out toward water in/out of cell)
  • Hydrophobic Head- hates water (point toward each other)
  • Diffusion- small molecules moving across plasma membrane from area of high concentration to low
  • Remember Febreeze activity and being stuck in the corner of the room and then spreading out
  • Osmosis- diffusion of water
  • When small molecules cannot diffuse, they can use membrane proteins to help
  • Channel Proteins- move water across membrane when there are large amounts of water to move; does not use energy
  • Carrier Proteins- molecules bind to protein and are moved across the membrane; use energy
  • When molecules are too big….
  • Endocytosis- engulfing large molecules; bringing them into the cell
  • Pinocytosis-engulfing liquids
  • Phagocytosis- engulfing solids
  • Exocytosis-“throwing up” molecules; taking them out of the cell
  • Passive Transport
  • No energy needed
  • Moves high to low
  • Diffusion, Osmosis, Channel Proteins
  • Active Transport
  • Uses energy
  • Moves from low to high
  • Carrier Proteins, Endocytosis, Exocytosis

Osmosis

  • Special word for water diffusing across the plasma membrane
  • Water moves from area of high concentration to low concentration
  • Easiest way to remember how water moves… After you drink something salty, you want water… Water will move to wherever it’s saltier
  • Isotonic- Water concentration same inside and outside of cell; water will move in and out at equal rates
  • Hypertonic- Water concentration is higher in cell; Water will move out of cell
  • Hypotonic- Water concentration is higher outside of cell; Water will move into cell

Photosynthesis and Cellular Respiration

  • Photosynthesis
  • Occurs in chloroplasts of plant cells
  • Makes food (glucose) for plants
  • Happens during the day, because sun is needed
  • 6H2O+ 6CO2+ sunlight  C6H12O6 (glucose) + 6O2
  • Needs carbon dioxide (CO2), makes oxygen (O2)
  • Cellular Respiration
  • Occurs in mitochondria of both plant and animal cells
  • Makes ATP (cell energy)
  • Happens anytime—day or night
  • C6H12O6 (glucose) + 6O26H2O+ 6CO2+ ATP
  • Needs oxygen (O2), makes carbon dioxide (CO2)

Mitosis & Meiosis

  • Mitosis-body cells reproduce; asexual reproduction
  • PMAT
  • Prophase- chromatin condenses into chromosomes; nuclear membrane breaks down
  • Metaphase- chromosomes line up along equator
  • Anaphase- chromosomes pulled to opposite end of the cell
  • Telophase- chromosomes begin to unravel; nuclear membranes reform
  • Cytokinsesis- cell pinches apart
  • Start with 46 chromosomes in 1 cell= end with two cells each with 46 chromosomes
  • Meiosis-sex cells reproduce; sexual reproduction
  • PMAT
  • Prophase I- chromatin condenses into chromosomes; nuclear membrane breaks down; homologous chromosomes find their match
  • Metaphase I- homologous chromosomes line up across from each other along equator
  • Anaphase I- each homologous chromosome pulled to opposite ends of the cell (don’t split in half this time; whole X moves to one side or the other)
  • Telophase I- first cell pinches into two; process begins again with two cells
  • Prophase II, Metaphase II, Anaphase II, Telophase II- just like PMAT in mitosis except happening in two cells instead of just one
  • Cytokinsesis- cell pinches apart
  • Start with 46 chromosomes in 1 cell= end with four cells each with 23 chromosomes (HALF)

DNA v. RNA

  • DNA is found in all living things
  • DNA is the blueprint for life
  • DNA and RNA made up of nucleic acids
  • Nucleotide- basic unit of DNA and RNA
  • Contain sugar, phosphate group, and nitrogen base
  • DNA has sugar called deoxyribose
  • RNA has sugar called ribose
  • Nitrogen bases on each strand of DNA/RNA pair up with a complementary base on the other strand
  • DNA- A=TC=G
  • RNA- A=UC=G
  • DNA is in the form of a twisted ladder aka DOUBLE HELIX
  • RNA is single stranded
  • Transcription- DNA is copied into mRNA
  • Translation- mRNA is copied into tRNA
  • tRNA is attached to amino acid
  • amino acids make a chain… a chain of amino acids make a protein
  • Mutations in DNA cause genetic variations
  • Mutations can be a adding letters, subtracting letters, switching letters, or reversing entire sections

Genetics

  • Gregor Mendel- Father of Genetics
  • Discovered how genes are passed down to offspring by studying peas
  • Dominant trait masks recessive trait
  • To have a recessive trait, you must have a recessive allele from BOTH parents (bb)
  • Homozygous- same allele from each parent (BB or bb)
  • Heterozygous- different allele from each parent (Bb)
  • Use Punnett square to determine odds of offspring

B b

BB / Bb
Bb / bb

BGenotype: BB, Bb, bb

Ratio: 1:2:1

bPhenotype: Brown, Blue

Ratio: 3:1

  • Incomplete Dominance: traits blend together, because neither is dominant
  • Ex. flower color
  • Codominance: both traits show up, because both are dominant
  • Ex. Cow spots, calico cats, blood type
  • Sex-Linked Traits: traits that are carried on the X or Y chromosomes
  • Sex-linked traits are almost always on the X chromosome
  • More common in males, because they only need one allele instead of two (XY vs XX)
  • Examples: XHXHXHXh XhXh XHY XhY
  • If a female is heterozygous, she is called a carrier (XHXh)
  • Pedigrees- family charts that help you tell how a certain trait is carried through the generations
  • Square-maleCircle-female
  • Dark- affectedLight-unaffected
  • Square and circle connected horizontally-married
  • Vertical lines-children
  • Each row is a generation

Evolution and Natural Selection

  • Evolution-change over time (usually a VERY LONG time)
  • Natural Selection- how evolution happens
  • Mutations occur
  • If the mutation is helpful, then that organism with survive and carry on the gene to the next generation
  • Over time, the population will shift and have more organisms with that mutation
  • Phenotype Distribution graphs
  • Stabilizing- same bell curve but skinnier; selects for average
  • Directional- graph shifts to one side or the other; selects for one extreme or the other
  • Disruptive- graph flips upside down; selects for extremes and against middle or average
  • Speciation- making of new species
  • Best way to tell if species are related is by looking at DNA
  • If DNA is not available, look at fossils or bone structure
  • Homologous structures- structures that evolved from a common ancestor (bones)
  • Analogous structures- same function but evolved separately (wings)

Classification

  • Ways of grouping organisms based on evolutionary similarities
  • Kingdom, Phylum, Class, Order, Family, Genus, Species
  • Kingdoms: Archaebacteria, Eubacteria, Protista, Fungi, Plantae, Animalia
  • Binominal Nomenclature- scientific name; use the organisms genus and species
  • Fan diagram- closer on chart means more closely related
  • Cladogram- shows relationships between species based on common features
  • The ones closest to the beginning (left) are the common ancestors to the ones toward the right
  • If one part branches, those species are the most related
  • Dichotomous Key- use key to determine classification of an unknown organism

Behavior

  • Innate- A behavior that is inherited from your parents
  • Ex. fight or flight, instincts, courtship
  • Learned- A behavior that is learned through practice after birth
  • Imprinting- organism creates a socially attachment quickly after birth and follows it around to learn behaviors for survival
  • Mendel! 
  • Trial and Error- organism is rewarded for a certain behavior
  • Making a nest
  • Conditioning- learning to respond to something by association
  • Pavlov’s dogs
  • Insight- use previous experiences to respond to new situation
  • Doing math problems