Light Microscope Introduction - A great virtual microscope simulation.
Virtual Histology Lab - A great collection of slides that include scale bars that can be used to practice calculations and drawings.
| | **Practical 2:** Estimation of osmolarity in tissues by bathing samples in hypotonic and hypertonic solutions. |This could be a grab bag activity. The students can either weigh potato pieces if they have a kitchen scale (such as this) at home or they could measure the change in size of a strip of potato if they do not have a kitchen scale.
Grab bag materials: salt, measuring cylinder (or equivalent), beakers (or simple containers), scale, salt, potato.
| | **Practical 3:** Experimental investigation of a factor affecting enzyme activity. |Catalase found in potatoes could be a viable experiment that could be done at home. This video offers a method.
Grab bag materials: 3% H202 (available at pharmacies), potatoes, kitchen scale (if you want to weigh the potatoes added), blender, ice, water, filter paper (coffee filters work also), beakers (or equivalent), measuring scales.
\*adding salt or vinegar to the solutions is a great way to modify this experiment for a practice IA. Additionally, the dilution of the 3% H202 or the potato solution is another variable that can be explored.
| | **Practical 4:** Separation of photosynthetic pigments by chromatography. |This can easily be done at home with a few caveats. First, coffee filters will not work well, there is just too little separation, but can be used if nothing else is available. Chromatography paper is the best and can be ordered online (see Amazon for an example). Recommended solvents, mostly poisonous, are: rubbing alcohol, nail polish remover (acetone), turpentine, or vinegar. Spinach is recommended as a source as it has an ample source of pigments. Here is a pretty simple method.
Grab bag materials: chromatography paper (coffee filters will work in a pinch), rubbing alcohol (or something equivalent), spinach, coins (depending on the method), beakers, ruler.
| | **Practical 5:** Setting up sealed mesocosms to try to establish sustainability. |This is a pretty easy one to set up at home. Two litre soda containers cut open work well, see this example from BioNinjia. Students can order their own plants, or collect them from around their house or grow them from seed (such as corn, beans, etc). Data collection will probably be limited to observations only and students could keep a journal.
Grab bag materials: Empty two litre bottle (or sealable jar), various plants and soil material.
| | **Practical 6:** Monitoring of ventilation in humans at rest and after mild and vigorous exercise. |A pretty easy experiment to run at home if a student simply counts the number of breaths per minute after different types of exercise. An extension of this experiment could be done on how long it takes a red cabbage indicator to turn red after different experiments due to increased CO2 concentrations. This will be very subjective and a great jumping off point into the reliability of some methods.
Grab bag materials: Nothing really except red cabbage if you are using it as a pH indicator.
| | **Practical 7:** (HL only) Measurement of transpiration rates using potometers. |This can be done using 0.5 mL or 1.0 mL pipette with rubber tubing at the end. The trick is to put the leaf or stem into the rubber tubing connected to the pipet while everything is underwater while making sure all the air bubbles are out of the pipet and tubing and a fresh cut is made, underwater, on the stem. You then need to cover the stem and tubing with vaseline to seal it. The stem, tubing and pipet can then be taken out of the water and taped to a window. The water tension will keep the water in the pipet and transpiration will cause the water to move up the pipet.
Grab bag materials: 0.5 mL or 1.0 mL pipette, rubber tubing, vaseline, tape
| **Other Labs:**\ Seed germination, plant growth, papain (found in papaya or pineapple) and gelatin, duckweed growth, yeast experiments are some of the other possibilities that could be done at home with relatively little equipment.