Ecology Big Ideas

Energy Energy flows through every ecological system – Inputs = what goes into the ecosystem – Outputs = what goes out of the system

Food Webs Increased biodiversity means a healthier ecosystem

Energy Transfer between Trophic Levels 10% Energy Transfer Producers make up largest biomass

Bioaccumulations Toxins cannot be removed and increase in amount between trophic levels

Carbon Cycle Cycles carbon through the ecosystem Contains photosynthesis and cellular respiration – Opposite chemical reactions

Nitrogen Cycle Cycles nitrogen through the system Bacteria takes nitrogen from the atmosphere and transfers it to plants

Population Growth Populations will grow exponentially if there are no limiting factors

Population Growth Populations will reach carrying capacity because of limiting factors which include: – Abiotic (non-living) Space & Water – Biotic (living) Food & Predators

Population Density Population Density is the number of living things in an area – Example: 500 moose in 10 sq. miles = 50 moose per mile

General Ecology Non-native species usually DIE in a new environment, some survive and take over if they have no predators

Sustainability Maintaining resources for future use Choices we can make now that support sustainability – Substituting renewable (?) for non-renewable (?) resources – Recycling – Using fewer resources

Macromolecules Carbohydrates: made of simple sugar units glucose, galactose, fructose Lipids: fats, etc. – Triglycerides made of glycerol & 3 fatty acid tails – Phospholipids made of phosphate head & 2 fatty acid tails

Macromolecules Proteins: made of amino acids Nucleic Acids – DNA & RNA: made of nucleotides

Cell Structure & Function Big Ideas

Main Cell Types Prokaryotes – no nucleus, nucleoid region of DNA; bacteria Eukaryotes – DNA contained in nucleus, membrane bound organelles; everything except bacteria

Key Cell Components/Organelles Nucleus – DNA Ribosomes – Site of Protein Synthesis Endoplasmic Reticulum – assembly of lipids & finishing work on proteins, etc. Golgi Apparatus – modifies, sorts and packages proteins, etc. from ER for storage or release to outside of cell. Mitochondria – breakdown of glucose into ATP Chloroplasts – convert sun energy into sugars Vacuoles & Vesicles – storage/movement of water, etc. Lysosomes – bread down of macromolecules and old organelles.

Cell Boundaries & Movement of Materials Across Them Cell wall – rigid structure outside cell membrane for support, protection; found in bacteria, fungi, plants Cell membrane – flexible barrier between inside and outside of the cell – Composed of phospholipid bilayer, proteins – Selectively permeable – allows some things in/out, but not others.

Cell Transport Passive Transport – no cellular energy used – Diffusion – movement of materials from high to low concentration – Facilitated diffusion – diffusion of molecules through protein channels (not directly through membrane) – Osmosis – movement of water from high to low concentration across a membrane (facilitated) Active Transport - requires cellular energy – Movement of materials across the membrane from low to high concentration

Photosynthesis and Cellular Respiration Big Ideas

Photosynthesis & Cellular Respiration Photosynthesis and cellular respiration are opposite chemical reactions

Photosynthesis: plants take carbon dioxide (CO 2 ) and water (H 2 O) and make glucose (C 6 H 12 O 6 ) and oxygen (O 2 ) – Plants make their own food!!!!!!!!!!!!!!!!

Cellular Respiration: plants AND animals make energy (ATP) by transforming glucose (C 6 H 12 O 6 )and oxygen (O 2 ) into carbon dioxide (CO 2 ) and water (H 2 O) – CHEMICAL Energy in glucose is transformed into the energy to live (ATP) – Very similar to setting something on fire (combustion), which releases carbon dioxide (CO 2 ) into the atmosphere

Be able to trace the path of a carbon atom from air through photosynthesis, cellular respiration and back to the air

Mitosis and Meiosis Big Ideas

Mitosis & Meiosis Division of Chromosomes in a cell Chromosomes are made of DNA DNA is replicated (copied) before each process Each chromosome contains many sections of DNA called genes which contain the code for a protein

Mitosis Mitosis: produces two IDENTICAL cells from one cell for growth and repair of body cells 2N cells produce 2N cells

Meiosis Meiosis: produces four UNIQUE sex cells for reproduction Each cell is 1N – ½ the chromosomes of the body cells – Females: Eggs – Males: Sperm Allows for differences (variation) in populations Fertilization restores the 2N number in offspring

Mitosis and Meiosis

DNA and Genetics Big Ideas

DNA: deoxyribonucleic acid; is a code for your physical (phenotype) traits -  PHYSICAL TRAIT DNA & Genetics

Traits Proteins: can be used to make body structures, hormones and enzymes – Enzymes act to speed up (catalyze) chemical reactions in the body Ex. Digestion of food, making DNA, and regulating glucose

Genetics Vocabulary Phenotype: What your physically look like Ex. Blue Eyes OR Brown Eyes Genotype: What your genes are Ex. Bb, bb, or BB

Vocabulary Dominant: Trait/gene that is shown Ex. BB = Brown Eyes Bb = Brown Eyes Recessive: Trait/gene that is hidden by a dominant gene Ex. bb = Blue Eyes Bb = Brown Eyes

Vocabulary Heterozygous: different genes – Ex. Bb for Brown Eyes Homozygous: same genes – Ex. bb for Blue Eyes

Punnett Square: used to predict offspring – Ex. Two heterozygous bunnies are crossed; black fur is the dominant trait – Phenotype ratio Ex. 25% white bunnies, 75% black bunnies – Genotype ratio Ex. 25% bb, 50% Bb, 25% BB F F f f FFFf ff

Earlobes (E) A detached earlobe man (EE) has children with an attached earlobe woman (ee). 1)What are the possible genotypes (gene combination)? 2)What are the possible phenotypes (physical trait)?

A heterozygous tongue roller (Tt) mates with a non-tongue roller (tt), what percentage of their children will be tongue rollers?

What is the percent chance two heterozygous tongue roller will have a non-tongue roller offspring?

Dihybrid crosses – chance of inheriting 2 traits together Cross 2 heterozygous for color and height (Green & Tall are dom; Yellow & Short are rec.) TTGG TtGG TTGg TtGg TtGG ttGG TtGg ttGg TTGg TtGg TTgg Ttgg TtGg ttGg Ttgg ttgg TG tG Tg tg TG tG Tg tg Red = tall Black= short

Protein Synthesis Transcription – The code in DNA is copied into mRNA – This nucleotide sequence determines the sequence of amino acids in the protein. – mRNA leaves the nucleus and forms a “protein factory” complex with rRNA called a ribosome. Translation – The nucleotide sequence in mRNA is read 3 nucleotides at a time – a codon. – Each codon corresponds to a specific amino acid. – tRNA brings the needed amino acid to the ribosome. – The amino acids are bonded together to form a protein.

Transcription Translation

Evolution Big Ideas

Evolution Evolution: change over time All living things are related to a COMMON ANCESTOR!!!

Evidence of Evolution Evidence: 1.Presence of Fossils found in rock layers 1.Homologous and Vestigial Structures Homologous: Similar Structures Vestigial: Unused structures; whale pelvis, human wisdom teeth

Fossil RecordHomologous Structures

Evidence of Evolution 3.DNA Comparisons Humans and mice are 99% similar in DNA, so they are closely related 4.Embryos Closely related organisms have similar embryos

DNA ComparisonsEmbryos

Natural Selection Natural Selection: “survival of the fittest, failure of the worst” – Over reproduction sets up a struggle for existence – Natural selection selects for variations in the population (result of mutation & sexual reproduction( that are adaptive – The “goal” of life is to survive and reproduce (pass adaptive genes to next generation)

Mutations in DNA: can (not always) lead to unique traits, which may help or hinder survival!! OrganismEnvironmentUnique Trait Bunny RabbitWinter CactusDesert CheetahAfrican Savanna ChameleonJungle PeacockMating Season

Mutations

Balancing Biological Systems Homeostasis

Homeostasis: regulation of systems to maintain balance Two things can affect homeostasis – Negative Feedback – Positive Feedback

Negative Feedback Negative Feedback: increase causes decrease, decrease causes increase – Ex. Automatic Thermostat: if temperature decreases in room, then the temperature increases – Negative ≠ bad

Positive Feedback: increase causes increase; decrease causes decrease – Ex. No shower for 2 weeks: smell from bacteria growth increases on a daily basis Positive ≠ good Positive Feedback

Negative or Positive Feedback?? Deforestation Regulating Body Temperature (too hot OR cold) Immune System Fighting Infection Body is Hungry P P N N

Choose two examples to complete a Negative Feedback Loop AND a Positive Feedback Loop Identify what HOMEOSTASIS would be Explain the STIMULUS that tells us homeostasis is not in balance Identify the CONTROL CENTER in the body (if there is one) that recognizes the stimulus Explain what RESPONSE occurs

Other System Examples Boundaries, inputs and outputs in an ecosystem (energy, biogeochemical cycles, population dynamics, etc.) Interaction of enzymes, substrates and products in biochemical pathway Organ systems

Scientific Method Reliability – – Increased by repeating an investigation = more trials Validity – – Increased by: Adding more controlled variables Improving measuring technique Controlling for sample bias Including an experimental control group

Different types of investigations Controlled experiments – A lab investigation in which the values of all variables are kept the same except for one that is changed from experiment to experiment (manipulated variable) and one that is measured (responding variable). – Have experimental and control groups – Include at least 3 levels of manipulated variable (if measuring effect of fertilizer on plant growth, use 10 g., 20 g. and 30 g. of fertilizer on different plants) – Include at least 3 trials for each condition (can be repetitions or more subjects). Field study – A scientific study of free-living plants or animals in which the subjects are observed in their natural habitat without changing, harming, or altering the setting or subjects. – No experimental and control groups – May include sampling, observation, etc.