Cells Big Ideas

Parts of the Cell Cell Membrane- The membrane that surrounds the cell. Controls what goes into and out of the cell Ribosomes -The sites of protein synthesis. This is the “workbench” where proteins are put together. Nucleus- Organelle that manages or controls all of the cell functions in a eukaryotic cell. “The control center, which contains DNA.” Chloroplast- Uses solar energy to convert carbon dioxide and water into glucose and oxygen. Site of photosynthesis. Mitochondria- Produces a usable form of energy (ATP) for the cell. Uses glucose, oxygen and water to make ATP, which cells use for energy.

Protein Channel Protein Channel Outside of Cell Inside of Cell Cell Membrane Structure & Function How will molecules move? (direction & route)

Molecules moving across a cell membrane is called diffusion. Water moving across a cell membrane is called osmosis. Passive transport uses NO energy and Active transport uses energy. Cell Membrane Structure & Function

Mitosis and Meiosis and Evolution Big Ideas

Mitosis Mitosis: produces two IDENTICAL cells from one cell for growth and repair

Meiosis Meiosis: produces four UNIQUE sex cells for reproduction – Females: Eggs – Males: Sperm Sex cells have half the DNA in a UNIQUE combination UNIQUE combinations allow for differences (variation) in populations

Mitosis and Meiosis

DNA and Genetics Big Ideas

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

DNA Structure DNA is a Double Helix – “Twisted Ladder” The rungs of the ladder are made of 4 distinct nucleotides – G, C, A and T

Making Proteins Transcription – DNA is read to make RNA Translation – RNA is read to make a protein

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 you 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)?

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

Evidence of Evolution Fossil RecordHomologous Structures Homologous and Vestigial Structures Presence of Fossils found in rock layers

Evidence of Evolution DNA Comparisons Humans and mice are 99% similar in DNA, so they are closely related Humans and bananas are 55% similar in DNA, so they are NOT closely related Embryos Closely related organisms have similar embryos

Natural Selection Natural Selection: “survival of the fittest, failure of the worst” – The “goal” of life is to survive and reproduce – Based on ability to survive in environment

Mutations in DNA: can (not always) lead to unique traits, which may help or hinder survival!! OrganismEnvironmental Pressure TraitsWhich one survives? What genes become more common in population? Bunny Rabbits WinterBrown Fur –or- White Fur GiraffeTall TreesShort Neck –or- Long Neck

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

C ATP CO 2 GLUCOSE

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

Ecology Big Ideas

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

Food Webs Increased biodiversity = a healthier ecosystem

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

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 Examples of limiting factors are: – Food – Water – Shelter – Space

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 square 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

Writing a Science Conclusion 1.Read the scenario – Write “things” or “stuff” above the words you don’t know 2.Look at the data table 3.Figure out the relationship between variables – Increase causes decrease OR decrease causes increase – Increase causes increase OR decrease causes decrease 4.Write conclusion based on DATA TABLE averages

Example Scenario Scenario: Tom and Jane wanted to find out how exposure to sunlight affected plant growth. Sunlight Exposure (hours) Plant Growth (cm) Trial 1Trial 2Trial 3Average 2 hrs hrs hrs hrs10868 Data: Sunlight Exposure vs. Plant Growth

Example sentences for each conclusion bullet point “As sunlight increases, plant growth increases.” “8 hours of sunlight caused the greatest plant growth at 8cm and 2 hours of sunlight caused the least plant growth at 1cm.” “So the plant exposed to MOST sunlight grew 7cm MORE THAN the plant exposed to the least sunlight.” “The explanation for this is that plants need sunlight to go through photosynthesis to grow.”