State Mandated Lab Review Living Environment State Mandated Lab Review
Lab 1: Diffusion and Osmosis
Definitions Diffusion: movement of molecules high concentration to low concentration. Osmosis: movement of water from a high concentration to a low concentration.
Concepts To Know The dialysis bag is the "cell membrane” Diffusion uses NO input of energy Small molecules will go through the selectively permeable membrane. Starch is too large and can not travel through the membrane.
Concepts To Know Benedict's solution: tests for sugar...heat it and it turns HALLOWEEN ORANGE if positive. Lugol’s Iodine Solution: tests for starch. Turns BLUE-BLACK if positive.
1. What does the tubing represent? Cell membrane 2. What is inside the tubing? Starch & glucose
3. What did we add to make the liquid outside the “cell” amber colored? Starch indicator (iodine)
4. Why does the inside of the “cell” turn purple or black? High s.i.conc. Low s.i. conc. Starch indicator diffused into the tubing
5. How do we know that starch did not move from the inside to the outside? No color change outside
6. How can we find out if glucose moved into the beaker? Glucose (high conc.) Do a glucose indicator test using the fluid in the beaker
7. After placing 10 drops of the beaker solution into a test tube, what do we add to it? Glucose indicator
8. After adding the glucose indicator solution (blue) what do we do with the test tube? Heat it
9. If there is glucose in the solution, what will happen to the blue color after heating the tube for 2 minutes? The color changes
10. The blue color changed to orange 10. The blue color changed to orange. This means that what substance is in the test tube? glucose
starch glucose C6H12O6 11. Glucose indicator solution was added to these test tubes, and then the tubes were heated. Which will change color?
Were you right?
Questions WHY MUST WE DIGEST STARCH BEFORE WE CAN USE IT FOR ENERGY ? ____________________________________________________________________________________________
Questions WHAT HAPPENS TO A CELL IN A HYPERTONIC SOLUTION ? WHAT HAPPENS TO A CELL IN A HYPOTONIC SOLUTION ? WHAT HAPPENS TO A CELL IN AN ISOTONIC SOLUTION?
Red Onion Plasmolysis Observation Before and after observations of red onion epidermis under the microscope (400X) Red onion under in hypertonic (salt) solution. Note cell membrane has “withdrawn” and the cytoplasm has lost water to the salty environment, making it appear smaller and darker. Red onion under in isotonic (normal) solution. Note cell membrane and cytoplasm almost completely “fill” the boundary of the cell wall.
Lab 2: Making Connections
Concepts To Know: Resting pulse rates vary among individuals. Pulse rate increases under physical or emotional stress. Exercise increases demand for oxygen and nutrients – therefore, heart must pump more blood to the area. Increase in activity produces muscle fatigue (build up of lactic acid). Use the Scientific Method to solve a problem that you have postulated. Title, Hypothesis, Methods/Materials, Data Collected, Conclusions, Suggestions for Improvement and Suggestions for further Research
Main Idea Will you be able to squeeze a clothespin more before or after exercising????? Some say “before”, some say “after” “Before” – you muscles are rested – there is not a build up of lactic acid in the muscles “After” – you are warmed up – extra blood is flowing to the area carrying more oxygen and nutrients to your cells.
Questions Question: Why does the heart beat faster during exercise? Answer: To carry more oxygen and nutrients to the cells that are being exercised. Increased nutrients and oxygen will allow more cell respiration to take place in mitochondria, increasing ATP output.
Lab 3: Beaks of Finches
Concepts To Know Charles Darwin studied finches on Galapagos Certain adaptations give some organisms an advantage to survive. Beak size varies on the Galapagos islands due to different food supplies. The environment "naturally selects" which organisms are best suited (fittest) to survive, reproduce and pass on their genes. Competition for resources (food, water, mates and territory) stimulates the struggle for survival.
Questions WHAT OTHER TRAITS COULD HELP FINCHES SURVIVE BESIDES THE SHAPE OF THEIR BEAKS ? __________________________________________
Relationships & Biodiversity Lab 4: Relationships & Biodiversity
Concepts To Know Organisms with similar structural or molecular similarities may share a common ancestor. In order for a species to be successful and survive it must contain variation. Proteins and enzymes are produced as a result of an organism's genetic code (DNA) sequence. The DNA code is transcribed from DNA mRNA, and translated from mRNA Protein Base-pair rule says that A-T and G-C;
Concepts To Know Amino acids are the building blocks of proteins Molecular similarities are the MOST IMPORTANT evidence of closely related organisms. Organisms evolve much like the branches growing on a tree. Biodiversity ensures genetic variation. Biodiversity increases stability in an ecosystem. Endangered species hold medicinal, agricultural. ecological, commercial and aesthetic value. They must be protected for future generations.
Concepts To Know Gel Electrophoresis is a technique used to separate DNA fragments according to size. Restriction enzymes are used to “cut” DNA at a specific code “CCGG” Chromatography is used to separate out the pigments of the plant extract. Similar color bands reveals similar plant.
Separates DNA fragments according to SIZE AND CHARGE! Gel Electrophoresis Separates DNA fragments according to SIZE AND CHARGE!
Test 4 – Paper Chromatography to Separate Plant Pigments Water migrates up paper via capillary action and carries plant pigments with it. B.curus X Y Z B.curus X Y Z “Spot” your chromatography paper and label it with a pencil.
Questions WHAT ACTIVITIES BY HUMANS COULD ENDANGER PLANTS ? ______________________________________
Question WHY IS BOTANA CURUS SO IMPORTANT ? HOW CAN IT BE SAVED ? ______________________________________
Question WHY WOULD SOME PEOPLE NOT WANT TO SAVE BOTANA CURUS EXTINCTION ? __________________________________________