Question 1
You are provided with a 7cm visking tubing. Immerse it in water for 1 minute. Remove it from water, rub it between your fingers to open it. Using one piece of cotton thread, tie one end tightly.Put 4cm3 of solution X in the visking tubing and tie the other end tightly using a piece of the other cotton thread. Rinse off the visking tubing using distilled water. Immerse it in iodine solution contained in a 100ml beaker. Leave the set up to stand for 10 minutes. Make observation and answer question that follow.
- Suggest the likely food substance contained in solution X.
- State the physiological process under investigation.
- Account for the observation made at the end of the process.
- Using the reagents provided, carry out tests to determine the food substances present in solution X. Write the procedure, observation and conclusion in the table below
Answer
- Starch
- Diffusion
- Iodine molecules are highly concentrated; moves into the Visking tubing by diffusion; reacting with solution x; thus blue-black colour observed in the Visking tubing; confirming x to be starch
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Question 2
You are provided with specimen B,C and D. Examine them and answer questions that follow
- State three observable differences between B and C.
- Name the divisions into which specimen B,C and D belong.
B-
C-
D- - Using a scalpel, carefully make a longitudinal section through C to have two equal mirror parts (similar halves). Draw one half and label the parts.
- Work out the magnification of your drawing
- Describe the androecium of the flower.
Answer
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- Divisions for
B- Bryophyta
C – Pteridophyta
D – Spermatophyta - - Any 8 points correctly labelled
- Complete drawing observing biological rules
- Expected parts labelled are:
- Sepal, petal, ovary, ovule, filament, pistil, anther, stigma, pedicel 