O Level Biology Practical 2020 Answers -

Candidates were provided with a solution of an enzyme and its corresponding substrate. They were required to measure the rate of reaction, often by counting gas bubbles produced per minute or tracking a color change using an indicator like iodine solution. Step-by-Step Answer Analysis 1. Constructing the Data Table

After placing a variegated leaf in sunlight, the green areas (containing chlorophyll) turn blue-black with iodine, while white areas remain brown. Explanation:

Students had to create a line drawing of five tubules from a cross-section. Precision Task:

Testing a variegated leaf for starch using the iodine test.

Use a to maintain temperature instead of just adding hot water. o level biology practical 2020 answers

, the reaction speed increases (faster bubble production). Above 50∘C50 raised to the composed with power C , the enzyme denatures, and the reaction stops.

A significant portion of the marks depended on a freehand drawing of a provided biological specimen or photomicrograph. Cambridge examiners look for strict adherence to standard biological drawing conventions:

O Level Biology Practical 2020 Answers: A Comprehensive Guide and Review

What control would you use to prove the reaction is due to the enzyme? Candidates were provided with a solution of an

In the 2020 O Level Biology Practical exam (specifically the Singapore 6093/03 paper), the main challenges centered on testing glucose concentrations in "urine" samples and identifying specimens under a microscope.

The students had been preparing for weeks, revising the concepts of photosynthesis, and practicing their experimental skills. As they entered the laboratory, they were greeted by the familiar sight of Elodea plants, microscopes, and various equipment needed for the experiment.

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.

Don’t just memorize answers. Learn why iodine turns blue-black (amylose helix trapping iodine) and why catalase works best at pH 7. That’s how you beat the 2021, 2022, and 2023 practicals too. Constructing the Data Table After placing a variegated

Questions often required detailed biological drawings and calculations of magnification. Drawing Requirements:

Improvement: Utilize a two-necked flask or a syringe system to introduce the substrate without breaching the closed environment.

Data: 0.0 M: mass change +12%; 0.2 M: +5%; 0.4 M: 0%; 0.6 M: −6%; 0.8 M: −12%.

The 2020 O Level Biology Practical examination tested candidates on four core skills: , (2) Observation & drawing , (3) Interpretation & analysis , and (4) Planning & evaluation . While specific answer sheets are confidential, the expected answers followed recurring themes: food tests, enzyme activity, osmosis, transpiration, and microscopy.