Correct use of Benedict's solution and accurate timing of color changes. Presentation of Data and Observations Organizing results into a professional table with units ( g/dm3g/dm cubed ACE Analysis, Conclusions, and Evaluation
This task required observing 15 seedlings grown in light and 15 grown in the dark. Stem Length o level biology practical 2020 answers
Common topics in the 5090 series included the effects of temperature on pigments and plant tissue reactions. Correct use of Benedict's solution and accurate timing
Answer: Elodea plants are used as a model organism to investigate photosynthesis. They produce oxygen as a byproduct of photosynthesis, which can be measured and used to estimate the rate of photosynthesis. Answer: Elodea plants are used as a model
| Test | Reagent | Positive Observation (Expected Answer) | |------|---------|----------------------------------------| | Reducing sugar | Benedict’s solution | Blue → Brick-red/orange precipitate upon heating | | Starch | Iodine solution | Brown/yellow → Blue-black | | Protein (biuret) | Biuret test (NaOH + CuSO₄) | Blue → Lilac/violet | | Fat (lipid) | Ethanol emulsion | Clear → Milky white emulsion |
Need more help? Leave a comment below with the specific variant (e.g., 5090/33/O/N/20) and question number, and we will provide the exact mark scheme answer.