biology pssa review. s tructure and f unction of organisms pssa eligible content s11.b.1.1 ( 1-3)
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ORGANIZATION - CELLS
Cells are the basic unit of life. All organisms (living things) are made of
cells. Unicellular
Made of one cell Ex: bacteria, protists, fungi (yeast)
Multicellular Made of many cells Ex: animals, plants, fungi
SUMMARY OF ORGANELLES
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
KEY CELL COMPOUNDS
TYPE DESCRIPTION/FUNCTION
PROTEIN Made of amino acidsMost abundantStructure, movement, chemical reactions
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
TRANSPORT ACROSS THE CELL MEMBRANE
Passive Transport Includes 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
HOMEOSTASIS
Maintenance of stable internal conditions required for cells to survive
CELL MEMBRANE plays key role Selective permeability
CLASSIFICATION OF ORGANISMS Taxonomy defined
Science of grouping organisms
BINOMIAL NOMENCLATURE: Genus/species Ex: Homo sapiens
DOMAIN
DOMAINS
EUBACTERIA ARCHAEA
Prokaryotic cells Do not contain membrane bound organelles NO NUCLEUS YES DNA
EUKARYA Includes Kingdoms Protista, Plantae, Animalia,
Fungi YES NUCLEUS YES membrane bound organelles
KINGDOMS
KINGDOM CELL NUMBER
DESCRIPTION EXAMPLES
ARCHAEA Uni Live in harsh environments
BacteriaNo specifics needed
EUBACTERIA Uni Typical prokaryotes
BacteriaNo specifics needed
PROTISTA Uni or Multi May have chloroplasts and cell wall
AmebaAlgae
PLANTAE Multi AutotrophicCell wall
Moss, fern
ANIMALIA Multi HeterotrophicLack cell wall
Sponges, worms
FUNGI Uni or Multi Lack cell wall and chloroplastsheterotrophic
Yeast, mushrooms
PHYLOGENY: USED TO CLASSIFY
o Evolutionary history of organismo Used to classifyo Shows ancestral relationships
DNA SEQUENCING: USED TO CLASSIFY
ORGANISM AMINO ACID DIFFERENCES
ORGANISM AMINO ACID DIFFERENCES
Human 0 Mouse 27
Gorilla 1 Kangaroo 38
Rhesus monkey
8 Chicken 45
Dog 15 Frog 67
Cow 25 Sea slug 127
Horse 25 Soy bean 124
Which organisms are the most closely related?
The ones with the least amount of differences!
PHOTOSYNTHESIS
6CO2 + 6H2O + 6O2 + C6H12O6 Carbon dioxide + water = oxygen +
glucose Changes radiant energy from sun into
chemical energy in glucose Occurs in chloroplast & uses chlorophyll 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
CELLULAR RESPIRATION (AEROBIC)
6O2 + C6H12O6 6H2O + 6CO2 + energy (ATP)
Energy in glucose is changed to ATP Occurs in 3 steps when oxygen is
present: GLYCOLYSIS
Produces 2 ATP (makes 4 and uses 2) Splits glucose into 2 molecules of pyruvate
KREBS CYCLE Also called citric acid cycle Transfers energy from pyruvate into energy holders
called FAD and NAD which become FADH2 & NADH
ELECTRON TRANSPORT Transfers energy from FADH2 and NADH into ATP
RESPIRATION (ANAEROBIC)
Oxygen is NOT present Glycolysis occurs (glucose is split) Following glycolysis- 2 choices
Alcoholic Fermentation yeast
Lactic Acid Fermentation Muscles in humans
EVOLUTION
Who developed the theory? Charles Darwin during the 1800s
What is EVOLUTION? Organisms change over time
Why do organisms change? Natural selection:
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 of the population over time
EVOLUTION
EVIDENCE? Fossils Similar body forms Similar embryos Similar DNA & amino acid sequences in proteins
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 Section of DNA which has a code for one trait
CHROMOSOME One molecule of DNA Humans have 46
CAN YOU…..
Complete the other half of the DNA molecule below?
A - T - C - G - G - C - A - T
T - A - G - C - C - G - T - A
GENETIC INFORMATION
REPLICATION Occurs before a cell divides in 2 Process in which DNA makes a copy of itself
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
GENETIC CODE
What amino acid is represented by the codon: UUU? phenylalanine (Phe)
What amino acid is represented by the codon: AUG?methionine (Met)
MITOSIS
PHASE DESCRIPTION
PROPHASE Nuclear membrane dissolvesSpindle apparatus forms
METAPHASE Chromatids align mid cell
ANAPHASE Chromatids separateNow are individual chromosomes
TELOPHASE Nuclear membrane reforms
MEIOSISMeiosis 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
PATTERNS OF INHERITANCE
DOMINANT & RECESSIVE GENES Genes occur in pairs The dominant gene is seen in the organism Recessive gene is masked
EXAMPLE: R = gene for right handedness r = gene 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: Used to predict probability of offspring having
certain characteristics/traits
Rr X Rr
PATTERNS OF INHERITANCE
MULTIPLE DOMINANCE Certain traits have more than 2 different forms Blood types occur from 3 different gene forms
(alleles)
A B O
AB are dominant together = type AB bloodA 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 INFLUENCED TRAITS Trait expressed differently in males and females MALE PATTERN BALDNESS
SEX LINKED TRAITS Are carried on X chromosome Sex chromosomes = X or Y Females = XX Males = XY COLOR BLINDNESS, HEMOPHILIA (blood clotting)
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
BIOMES
large, distinctive complexes of plant communities distinguished by climate.
There are 7 major land biomes, 1 major aquatic biome and numerous minor biomes Tundra Taiga Temperate Deciduous Forest Grasslands Desert Temperate Rainforest Tropical Rainforest Coral Reef
BIOMES
Extremely cold Covered by a
permanently frozen layer of ground called permafrost
Little vegetation (sphagnum moss, fast growing annuals)
Very few large predators (caribou, migrating birds, polar bears, arctic foxes)
Extremely hot Rainfall: <10”
annually, may be zero Little vegetation,
cacti, fast growing annuals
Very few large predators (snakes, lizards, birds, coyotes) Usually nocturnal
Tundra Desert
BIOMES
Large variety of tall, densely packed vegetation
Largest variety of biodiversity on land
Very few LARGE predators
Average temperature of 72-80o F
Two seasons: wet & dry (actually less wet)
Large variety of marine plants & sessile (stationary) animals (i.e. coral, sponges)
Largest variety of marine life
Very few LARGE predators (rarely higher than shark)
Average water temperature range of 68-82o F
Tropical Rainforest Coral Reef
BIOMES
4 seasons: summer, fall, winter, & spring
Most trees are hardwood (beech, oak) which shed their leaves in the fall (deciduous). Large groves of 1 tree type are common
Location: Eastern ½ of US & most of Europe
Deer, raccoon, salamanders & bear are common predators
4 seasons: summer, fall, winter, & spring
Most trees are coniferous, but smaller, shade loving trees (dogwood, maples) grow as well.
Location: Western edge of North & South America where moist Pacific Waters give plenty of rain.
Birds, bear & small animals are common predators
Deciduous Forest Temperate Rainforest
BIOMES
Known as the Prairie or Plains in US, Steppe in Russia & Savannah in Africa.
Shallow rooted grasses are most common, but along rivers & lakes, trees may grow.
Dominant predators are ungulates (i.e.bison, deer, antelope), prairie dogs, wolves, coyotes, bear
Climate: long snowy winters, long warm summers
Shallow rooted coniferous (pine) trees circling the earth like a belt
Dominant predators are the mosquitoes, moose, & migratory birds. Most other mammals hibernate during the long winter months.
Climate: long snowy winters & short warm summers.
Grasslands Taiga
PATTERNS OF CHANGE IN SYSTEMS
POPULATION Group of organisms in same species @ same
location POPULATION DENSITY
How crowded area is: # individuals /unit area GROWTH RATE
Amount population # changes / unit time Death/birth rates immigration/emigration
DENSITY INDEPENDENT FACTORS Weather, flood, fire
DENSITY DEPENDENT FACTORS Resource limitations: food, space, shelter,
nesting
PATTERNS OF CHANGE IN SYSTEMS
BIOLOGICAL DIVERSITY Variety in number of different kinds of species in
area SPECIES RICHNESS
Contributes to overall well being of environment and enhances survival of organisms: BALANCE
PRODUCERS Plants / use sun’s energy
CONSUMERS Eat other organisms
DECOMPOSERS Return nutrients to environments
PATTERNS OF CHANGE IN SYSTEMS
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
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