31112933
Description
Flashcards by thivya sachithanandam, updated more than 1 year ago
|
Created by thivya sachithanandam
over 3 years ago
|
|
| Question | Answer |
| Required practical 1 : Microscopy Preparing a microscope slide |
- methylene blue for staining cheek cells
-avoid smudging the glass slide or trapping air bubbles under the coverslip
Image:
Image (binary/octet-stream)
|
| Required practical 1 : Microscopy Using a microscope | |
| Required practical 1 : Microscopy Biological drawings | |
| Required Practical 2 : Microbiology Growth method | |
| Required Practical 2 : Microbiology Growth analysis | |
| Required Practical 3 : Osmosis Osmosis method | |
| Required Practical 3 : Osmosis Osmosis method | |
| Required Practical 3 : Osmosis Osmosis method | |
| Required Practical 3 : Osmosis Osmosis method VARIABLES | DEPENDENT: mass and the length of each potato cylinder before and after it has been submerged in solution INDEPENDENT: concentration of salt/sucrose solution in mol/dm3 CONTROL: type & volume of solute in solution, temperature and time |
| Required Practical 3 : Osmosis Osmosis analysis | |
| Required Practical 3 : Osmosis Osmosis analysis | |
| Required Practical 4 : Enzymes | Method Place single drops of iodine solution in rows on the tile Label a test tube with the pH to be tested Use the syringe to place 2cm3 of amylase in the test tube Add 1cm3 of buffer solution to the test tube using a syringe Use another test tube to add 2cm3 of starch solution to the amylase and buffer solution, start the stopwatch whilst mixing using a pipette After 10 seconds, use a pipette to place one drop of the mixture on the first drop of iodine, which should turn blue-black Wait another 10 seconds and place another drop of the mixture on the second drop of iodine Repeat every 10 seconds until iodine solution remains orange-brown Repeat experiment at different pH values – the less time the iodine solution takes to remain orange-brown, the quicker all the starch has been digested and so the better the enzyme works at that pH |
| Required Practical 4 : Enzymes Improvements to method | can be adapted to control temperature by using a water bath at 35℃ All solutions that need to be used should be placed in a water bath and allowed to reach the temperature (using a thermometer to check) before being used colorimeter can be used to measure the progress of the reaction more accurately; with a solution containing starch being darker and glucose light (as a result of the colour-change of iodine) – this will affect the absorbance or transmission of light in a colorimeter |
| Required Practical 5: Food Tests Food test colour changes table | |
| Required Practical 5: Food Tests Preparing a food sample | Break up the food using a pestle and mortar Transfer to a test tube and add distilled water Mix the food with the water by stirring with a glass rod Filter the mixture using a funnel and filter paper, collecting the solution Proceed with the food tests |
| Required Practical 5: Food Tests Benedict's test for sugars | |
| Required Practical 5: Food Tests Iodine test for starch | |
| Required Practical 5: Food Tests The emulsion test for lipids | |
| Required Practical 5: Food Tests The biuret test for protein | |
| Required Practical 5: Food Tests Important hazards | Biuret solution contains copper (II) sulfate which is dangerous particularly if it gets in the eyes, so always wear goggles Iodine is also an irritant to eyes (wear goggles) Sodium hydroxide in biuret solution is corrosive, if any chemicals get onto your skin wash hands immediately Ethanol is highly flammable; keep it away from the Bunsen burner used in the Benedict’s test (you should turn the Bunsen off completely) And of course, the Bunsen itself is a hazard! |
| Required Practical 6: Photosynthesis Rate | Method : Place a piece of pondweed (Elodea or Cabomba are often used), into a beaker of water Use a light a set distance from the plant Record the number of bubbles observed in three minutes Repeat steps for different distances |
| Required Practical 6 : Photosynthesis Rate Improvements | Use a gas syringe to collect the volume of gas produced Repeat the experiment at least twice for each distance and calculate the mean number of bubbles Use of a glass tank between lamp and plant to prevent heating of the plant, or using an LED bulb that releases very little heat energy |
| Required Practical 6 : Photosynthesis Rate Variables & Results | 3 independent variables for this: light, carbon dioxide and temperature |
| Required Practical 8 : Plant growth Method (diagram) | |
| Required Practical 8: Plant growth Investigating the gravitropic response (set-up) | Add some damp cotton wool to two petri dishes Place 3 bean seedlings in the cotton wool in each petri dish A – radicle facing downwards B – horizontally C – radicle (root grows from here) facing upwards Cover each dish with a lid Attach one petri dish to a support so that it’s on its side Attach the second petri dish to a clinostat (as shown in the diagrams above). Place both in a light-proof box (so that the seedlings are in complete darkness), leave for two days and then observe growth of the seedlings |
| Required Practical 8 : Plant growth Analysis of results | In the first petri dish all radicles (roots) have grown downwards (positive gravitropic response) regardless of which way they were initially facing (horizontal, up or down) and all plumules (shoots) have grown upwards (negative gravitropic response) In the second petri dish, all radicles and all plumules have all grown neither up nor down but straight outwards in whichever direction they were placed as the effect of gravity has been cancelled out by the revolving of the clinostat – they have shown no gravitropic response at all The experiment needs to be done in a lightproof box in order to cancel out the effect of light on the growth of the seedlings |
| Required Practical 7 : Reaction Time Control variables | The person catching the ruler using their dominant hand each time Dropping the same ruler from the same height each time, with the ruler orientated in the same direction (0 cm facing down) If the effect of caffeine is being investigated then none should have been consumed before the start of the experiment, or the room is silent for the first run if background noise is being altered reaction time investigation using a computer; more precise as it removes human error from measurements Reaction time can also be recorded in milliseconds which is more accurate than seconds |
| Required Practical 7 : Reaction Time Method | |
| Required Practical 7 : Reaction Time Method | |
| Required Practical 7 : Reaction Time Method (This experiment is prone to lots of errors and there are many factors that can affect the results. Repeat as many times as possible!,) |
Want to create your own Flashcards for free with GoConqr? Learn more.