(a)(i) Cut a pieces of specimen A, place it on the white tile. Add a few drops of iodine solution. Record the observation and result in a tabular form.
(ii) Squeeze a few drops of specimen E on another clean white tile provided, add a few dre Record the observation and result in a tabular form.
(b)(i) State two observables differences between specimens A and B. (ii) Suggest two factors that are likely to be responsible for the state of specimen B.
(iii) With the aid of hand lens/magnifying lens, observe.specimen B. and name an organism that is likely growing on it. (iv) State the mode of feeding of the organism on specimen B (c) ) Make a drawing 6cm-8 cm long, of specimen C and label fully. one function each of any three parts labeled.
Explanation
(a) Food Test
|
Observation |
Result |
|
Specimen A/bread/it; turns blue-black/blue/black |
Starch present |
|
Specimen E/orange juice turns brownish/yellowish |
Starch absent |
(b)(i) Observable differences between specimens A and B
-Specimen A is white/ cream in color while specimen B is dark brown/black in color
-Specimen A is soft in texture while Specimen B is hard in texture
-Absence of mould/Rhizopus/Mucor in specimen A, while in specimen B, there are presence of mold/mould, fungus/fungi/Rhizopus/Mucor.
- Specimen A is fresh, while specimen B is stale/decaying
(ii) Factors responsible for the state of Specimen B
- Moisture/water/humid air/humidity;
-Warmth/temperature
- Spores of fungus/fungi;
- Time.
(iii) Name of Organism : Mold/mould/fungus/fungi/Rhizopus/Mucor.
(iv) Mode of feeding Saprophytic.
(c)(i) Diagram/drawing of longitudinal section of Specimen C/boiled egg
(ii) Function of labeled parts:
-Shell: Protection/aeration/shape/gaseous exchange;
-Shell membrane allows gaseous exchange,
-Albumen: Supplies protein;
-YoIk: Provides food for embryonic growth/embryo;
- Air space: allows exchange of gases;
- Chorion protects the embryo/yolk sac.