Biology-S

1. Biology-S Open-Ended Review

2. Question 1 – Safety Rules • Wear protective equipment including goggles, aprons, and gloves • When using heat – always use tongs or heat gloves – never point heated objects towards people. • Waft to smell unknowns • No food or drink in the lab • Carry and use sharp objects (scalpel or scissors) appropriately

3. Question 2 – Diffusion and Osmosis • Osmosis – diffusion of water • Hypertonic – more solute outside the cell, water gets sucked out • Hypotonic – less solute outside the cell, water gets sucked in • Isotonic – concentration of solute is equal on both sides • Quick experiment – the gummy bear with the salt and plain water.

4. Question 3 – Cell Organelles • Cell membrane – monitors materials into and out of the cell • Active transport – move against a concentration gradient (pumps) • Passive transport – no energy required to move molecules • Facilitated diffusion (carrier proteins) • Channels

5. Question 4 - Genetics • Homozygous dominant – RR (red) • Homozygous recessive – rr (white) • Heterozygous – Rr (red) • RR x RR (100% RR, 100% red) • rr x rr (100% rr, 100% white) • RR x rr (100% Rr, 100% red) • Rr x Rr (25% RR, 50% Rr, 25% rr, 75% red, 25% white) • RR x Rr (50% RR, 50% Rr, 100% red) • rr x Rr (50% Rr, 50% rr, 50% red, 50% white)

6. Question 5 – Base pairing rules • DNA to DNA • A=T, C=G • DNA to mRNA (creates codons) • A=U, C=G • mRNA to rRNA or tRNA (creates anticodons) • A=U, C=G

7. Question 5 – Determining amino acids • Using the mRNA codon • First letter = left side of table • Second letter = top of the table • Third letter = right side of the table

8. Question 5 – Protein Synthesis • Two steps • Transcription – mRNA copies DNA in the nucleus • Translation – mRNA carries information to the ribosomes where rRNA and tRNA translate the mRNA to obtain amino acids and build proteins

9. Question 6 –Prokaryote v. Eukaryotes • Prokaryotes • No defined nucleus • No membrane-bound organelles • Believed to be earliest known cells • Eukaryotes • Well defined nucleus • Membrane bound organelles • Believed to have evolved from symbiotic prokaryotes

10. Question 7 –Well-designed experiment • Control – something to compared against (can be positive or negative) • Independent variable – variable that experimenter controls (example – time) • Dependent variable – variable that the experimenter is collecting data on (example – growth of a plant)

11. Question 8 – Macromolecules • Carbohydrates – used for energy • Lipids – long term energy storage, protective coating (wax) • Proteins – structure • Nucleic acid – information storage

12. Question 9 –Ecological interactions • Mutualism – everyone wins! All parties benefit (wrasse and pleny) • Commensalism – I win, you are neither helped nor harmed (barnacles on a whale) • Parasitism – I win, you lose! (tape worms, ring worms)

13. Question 10 –Food web • Producers – photosynthetic organisms • Primary consumers – herbivores • Secondary consumers – carnivores • Higher order consumers – top predators (humans, eagles, lions etc.)

14. Question 11 –Photosynthesis and Cellular Respiration • Photosynthesis • 6CO2+6H2OC6H12O6+6O2 • Reactants – carbon dioxide, water (in the presence of sunlight) • Products – glucose and oxygen • Cellular respiration • C6H12O6+6O2 6CO2+6H2O • Reactants – glucose and oxygen • Products – carbon dioxide and water The products of photosynthesis “power” the process of cellular respiration which “powers” all the other processes that living things do!

15. Good Luck! • If you paid attention during this review and you look these questions over a couple of times … • You are prepared for the open-ended portion of the Biology-S exam! • 12 questions  you pick 15. • Budget your time accordingly on test day.