BIOLOGY KEYSTONE REVIEW
Dec 24, 2015
TEST TAKING STRATEGIES
Read the question, pick out KEY TERMSThere may be different forms of terms you
are familiar withExample: Homeostatic Mechanism
Homeostasis = Ability to maintain equilibrium
Mechanism = How something is doneSo…Homeostatic Mechanism = The way an organism maintains equilibrium. An example would be shivering when cold
TEST TAKING STRATEGIES
“Attack” the question by breaking it down Determine what the question is asking you to
explain/answer
Use caution – look for words like ALWAYS, EXCEPT, NOT TRUE
Read ALL choices for a multiple choice before selecting an answer
Use “process of elimination” for multiple choice to narrow down your choices
TEST TAKING STRATEGIES
For essay/writing questions, tell the person what you KNOW, they will not assume what you mean.
For essay/writing questions, use definitions when possible.
SPELL CORRECTLY
Answer ALL questions. Blank = NO CREDIT
Double check answers with any extra time you have
PROKARYOTIC CELLS VS. EUKARYOTIC CELLS
Eukaryotic Cell Prokaryotic Cell
Nucleus: Present Absent
Number of chromosomes:
More than one-linear
One—circular; may contain plasmids= small circular DNA which often gives bacteria resistance to antibiotics
Cell Type: Multicellular Unicellular
True Membrane bound Nucleus: Present Absent
Example: Animals and Plants Bacteria and Archaea
ORGANIZATION - CELLS
Cells are the basic unit of life. All organisms (living things) are made of
cells. Unicellular – Can be Prokaryotic or Eukaryotic
Made of one cell Ex: bacteria, protists, fungi (yeast)
Multicellular – Eukaryotic only Made of many cells Ex: animals, plants, fungi
SUMMARY OF ORGANELLES (IN EUKARYOTES)
ORGANELLE FUNCTION
MITOCHONDRION Powerhouse of cell; makes ATP
RIBOSOME Proteins made here
NUCLEUS Houses DNA
NUCLEOLUS Makes ribosomes
ENDOPLASMIC RETICULUM Transport/ 2 types (rough/smooth)
GOLGI BODY Packaging
CHLOROPLAST Glucose productionSite of photosynthesis
CILIA / FLAGELLA: responsible for cell movement
WATER AND ITS PROPERTIES
• Changes in external heat do not easily effect the temperature of water• Ex – Oceans do not freeze
• Frozen water is less dense that liquid water• Ex – Lakes freeze on top, but not throughout
• Water molecules bond strongly to each other
• Water is the “universal solvent” – It is a polar molecule and readily dissolves many substances
CARBONWhy is Carbon suited to form macromolecules:
Carbon is the second most abundant element in
living organisms
Carbon can share four electrons, therefore it can
bond to four additional atoms
Carbon establishes covalent bonds (stable, high energy bonds)
KEY CELL COMPOUNDS – CARBON MACROMOLECULES:
TYPE DESCRIPTION/FUNCTION
PROTEIN Made of amino acidsMost abundantStructure, movement, chemical reactions. Some are ENZYMES
CARBOHYDRATE Includes sugars, starches, cellulose (plant support)Provides energy
LIPID Includes waxes and oilsDo not dissolve in waterEnergy storageCell membrane structure
NUCLEIC ACID Includes DNA, RNA & ATPStore hereditary informationDirect cell activities
ENZYME / CATALYST
Catalyst = Speeds up a reaction Enzyme = A type of catalyst
Found in biological systems Composed of proteins
ENZYME / CATALYST
Activation Energy (Ea)
Enzymes / Catalysts can be affected by: Temperature pH Concentration
ATP
The energy “currency” of life It is the high-energy molecule that stores the
energy we need to do just about everything we do.
It is present in the cytoplasm and nucleoplasm of every cell
PHOTOSYNTHESIS 6CO2 + 6H2O + energy 6O2 + C6H12O6 Carbon dioxide + water = oxygen +
glucose Changes radiant energy from sun into
chemical energy in glucose Occurs in chloroplast & uses chlorophyll
PHOTOSYNTHESIS
Occurs in 2 steps: Light dependent reaction
Energizes electrons in chlorophyll; makes ATP Splits water and releases oxygen
Light independent (dark) reaction Also called Calvin cycle ATP used to form glucose
MITOCHONDRIA:• “Power House of the Cell”
• Generate most of the cell's supply of adenosine triphosphate (ATP),
CELLULAR RESPIRATION (AEROBIC)
6O2 + C6H12O6 6H2O + 6CO2 + energy (ATP)
Chemical Energy in glucose is changed to Chemical Energy in ATP
Occurs in 3 steps when oxygen is present: GLYCOLYSIS
Splits glucose to produces 2 ATP KREBS CYCLE
Glucose broken down farther to make additional ATP
through ELECTRON TRANSPORT
RESPIRATION (ANAEROBIC)
Oxygen is NOT present Glycolysis occurs (glucose is split) Following glycolysis- 2 choices
Alcoholic Fermentation yeast
Lactic Acid Fermentation Muscles in humans
HOMEOSTASIS
Maintenance of stable internal conditions required for cells to survive
CELL MEMBRANE (PLASMA MEMBRANE) plays key role Selective permeability
TRANSPORT ACROSS THE CELL MEMBRANE Passive Transport
Includes diffusion Includes facilitated diffusion Does not require energy Substances move from high to low concentration With concentration gradient Osmosis is diffusion of WATER across membrane
TRANSPORT ACROSS THE CELL MEMBRANE
Active transport Requires energy (ATP) Substances move from LOW to high
concentration Against concentration gradient Will include Pumps, Endocytosis and Exocytosis
COMPARISON OF TRANSPORT METHODS:
Active transport requires energy whereas passive transport does not
Active transport involves the carrying of molecule against or solute against a concentration gradient
-Pumps, Endocytosis, Exocytosis Passive transport involves carrying of a
molecule along the concentration gradient Diffusion, Osmosis, Facilitated Diffusion
CELL CYCLE
Or MEIOSIS
CHROMATIDS
Division of cytoplasm
Ex - spinal, nerve and brain cells.
Interphase = G1, S and G2
MITOSISNUCLEAR DIVISION – SOMATIC/BODY CELLS
PHASE DESCRIPTION
PROPHASE Nuclear membrane dissolvesSpindle apparatus forms
METAPHASE Chromatids align mid cell
ANAPHASE Chromatids separateNow are individual chromosomes
TELOPHASE Nuclear membrane reforms
MEIOSISNUCLEAR DIVISION – SEX CELLS
Meiosis I
Meiosis II
Stage Description
Prophase I Spindle fiber formsPairing of homologous sets
Metaphase I Align center of cell
Anaphase I Homologous pairs split
Telophase I 2 new cells= ½ # chromosomes with copies
Stage Description
Prophase II Spindle fiber forms
Metaphase II Aligns mid cell
Anaphase II Chromatids separate
Telophase II Total 4 new cells
GENETIC INFORMATION
MITOSIS MEIOSIS
Creates identical cells Creates sex cells (gametes)
Exact same # of chromosomes
½ number of chromosomes
Diploid to diploid or haploid to haploid
Diploid (2 sets of chromosomes) to haploid (1 set of chromosomes)
No genetic variety Creates genetic variety
GENETIC INFORMATION
DNA Nucleic acid made of phosphate, sugar
(deoxyribose), and nitrogen bases (adenine, guanine, cytosine, thymine)
Base pairing: A = T C = G Basic building block: nucleotide Stores the genetic code
GENE / ALLELE Section of DNA which has a code for one trait
CHROMOSOME One molecule of DNA Humans have 46
PATTERNS OF INHERITANCE
DOMINANT & RECESSIVE GENES/ALLELES Genes/Alleles occur in pairs The dominant gene is seen in the organism Recessive gene is masked
EXAMPLE: R = gene/allele for right handedness r = gene/allele for left handedness In general:
if you have a gene for both right handedness and left handedness, you will be RIGHT HANDED
GENETICS
Punnett Squares: Determines Genotype Used to predict probability of offspring having
certain characteristics/traits/phenotypes/appearance
(teachers – click to fill in answers)
Example: Rr X Rr
R
r
R r
RR
Rrrr
Rr
PATTERNS OF INHERITANCE
MULTIPLE ALLELES Certain traits have more than 2 different forms Blood types occur from 3 different gene forms
(alleles)
A B O
AB are co-dominant (dominant together )= type AB blood
A and B are dominant over O AA, AO = type A BB, BO = type B OO = type O
Type O blood is the UNIVERSAL DONOR
PATTERNS OF INHERITANCE
SEX LINKED TRAITS Are carried on X chromosome Sex chromosomes = X or Y Females = XX Males = XY COLOR BLINDNESS, HEMOPHILIA (blood clotting)
CHANGES TO COMPOSITION AND NUMBER OF CHROMOSOMES
Crossing over
Nondisjunction
o Duplication
GENETIC MUTATIONS
Nonsense mutationsA nucleotide mutation creates a codon that STOPS the transcription process earlier than it should.
Silent mutationsA change in one base that still creates the amino acid that was desired.
Frameshift Mutation The addition of or the removal of a nucleotide causes all following codons to be read incorrectly
PATTERNS OF CHANGE IN SYSTEMS
RENEWABLE RESOURCES Can be replaced or renewed through natural
processes Ex: air, soil, water, living things
NONRENEWABLE RESOURCES Cannot be replaced by natural processes as quickly
as they are used Ex: coal, oil, natural gas, minerals
GENETICALLY ENGINEERED PRODUCTS Altering of genetic makeup to produce desired traits
ORGANIC FOOD PRODUCTION Growing of crops or raising of livestock without use
of synthetic chemicals
RNA AND DNA
DNA RNA
Stays in nucleus Throughout cell
Sugar = deoxyribose Sugar = ribose
Double stranded Single stranded or globular
Adenine, guanine, cytosine, thymine
Adenine, guanine, cytosine, URACIL
3 TYPES OF RNAmessenger (mRNA) nucleus to cytoplasm (ribosome)transfer (tRNA) cytoplasm to ribosomeribosomal (rRNA) makes up ribosomes/in nucleolus
too
GENETIC INFORMATION
TRANSLATION Reading of mRNA into a protein Every 3 bases on mRNA (CODON) – 1 amino acid tRNA (transfer RNA) retrieves amino acid from
cell Carries to ribosome to be put into protein
PROTEIN PRODUCTION:
Ribosomes: They are responsible for assembling the proteins of the cell.
Endoplasmic Reticulum: Manufacturing site for proteins.
Golgi Apparatus: Packages proteins inside the cell before they are sent to their destination
Nucleus: DNA is found in the nucleus, which is the template for protein production.
GENETIC INFORMATION
REPLICATION Occurs before a cell divides in 2 Process in which DNA makes a copy of itself
CAN YOU…..
Complete the other half of the DNA molecule below? (Teachers – give time to answer then click to check!)
A - T - C - G - G - C - A - T
T - A - G - C - C - G - T - A
EVOLUTION
Who developed the theory? Charles Darwin during the 1800s
What is EVOLUTION? Organisms change over time
Why do organisms change? Natural selection:
Organisms pass on traits through their genes/alleles All organisms have slightly different characteristics. If
these characteristics/adaptations help them survive in a particular environment, they will pass the traits on to their offspring- thus changing the characteristics and the allele frequency of the population over time
EVOLUTION
EVIDENCE? Fossils Similar body forms Similar embryos Similar DNA & amino acid sequences in proteins
FACTORS CONTRIBUTING TO NEW SPECIES:
1. Migration - the movement of genes into or out of a population. This includes pollen or seeds blowing into the population from a source that is otherwise considered to be a separate population.
2. Genetic drift - some individuals may, just by chance, leave behind a few more descendents (and genes, of course!) than other individuals. The genes of the next generation will be the genes of the “lucky” individuals, not necessarily the healthier or “better” individuals.
3. Isolating Mechanisms - something (as a geographical, ecological, physiological, anatomical, or psychological barrier) that limits breeding between groups.
4. Founder Effect – the gain of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population.
SCIENTIFIC METHOD A scientific theory is an explanation inferred from
multiple lines of evidence for some broad aspect of the natural world and is logical, testable, and predictive.
As new evidence comes to light, or new interpretations of existing data are proposed, theories may be revised and even change; however, they are not tenuous or speculative.
A scientific hypothesis is an inferred explanation of an observation or research finding; while more exploratory in nature than a theory, it is based on existing scientific knowledge.
A scientific law is an expression of a mathematical or descriptive relationship observed in nature.
BIOTIC AND ABIOTIC COMPONENTS OF ECOSYSTEM
Biotic factors: all the living things in an environment (i.e. bacteria, plants, insects, birds, and other animals).
Abiotic: all the non-living things in an environment (i.e. wind, precipitation, temperature, current in a stream, soil, caves).
ENERGY TRANSFERS IN ECOSYSTEM
o SUN is ultimate energy source on planet!
Food chains show the movement of energy through an ecosystem.
Sun grass grasshopper mouse snakehawk
Grass = producer (autotroph)Grasshopper = primary consumer (herbivore)Mouse = secondary consumer
(carnivore)Snake/hawk = tertiary consumers
POPULATION DYNAMICS
POPULATION Group of organisms in same species @ same
location POPULATION DENSITY
How crowded area is: # individuals /unit area
LIMITING FACTORS:
Weather, flood, fire
Resource limitations: food, space, shelter, nesting
These can lead to population decline or species elimination
BIOTIC INTERACTIONS OF ECOSYSTEMS Symbiosis - When two (or more) species live and
interact closely together
Competition - Happens when 2 (or more) organisms both try to use the same limited resource
Predation - When one organism (the predator) captures and kills another organism (the prey) for food
HUMAN AND NATURAL DISTURBANCES LEAD TO:
ECOLOGICAL SUCCESSION Communities replaced by newer communities
due to a change in an area PRIMARY
Occurs in area where no community exists Can follow a disaster (volcanic eruption/earthquake)
SECONDARYSoil intactExisting community cleared by disturbance (ex: farming)
PIONEER SPECIES First organisms to inhabit ecosystem