Biology expo waec 2017

Theory
1ai) Classifications of living things consists of placing together in categories those living things that resembles each other. It involves placing living things into groups that have certain features in common which distinguish them from other groups
1aii) Car von Linnè Also known as Carolus Linnaeus
1aiii)-Classification is important because it allows scientists to identify the organisms
-Classification is important because it makes it easy for scientists to group the organisms.
- It is also good to properly name organisms via a standardized system
1aiv)-Kingdom
- Phylum(Animal) or division (Plant)
-Class
-Order
-Family
-Genus
-Species
1bi) -Vírus can reproduce when present in another living cell
-It possesses characteristics which can be transmitted from one generation to the next
1bii) -When a virus is extracted from a living cell and placed in a non living medium, it assumes a crystalline form and thus become non-living
-Virus cannot respire, excrete or respond to stimuli
1ci) -Rosette disease
- Cassava mosaic disease
1cii) -Chicken Pox
-Polio
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2a)i They catalyse reactions by lowering the activation energy of a reaction
ii). They are regenerated after each reaction
iii). They are substrate specific, hence only molecules which are complementary to their shape can bind to it.
iii). They aid in metabolism (anabolism and catabolism)
2bi)-Pancreatic lipase
- Amylase
2bii)-Fats and oil
-Starch Maltose
2biii) -It converts fat and oils to fatty acids and glycerol
-It converts starch to maltose
2ci)Chlorophyll is necessary to absorb the radiant energy of the sun to synthesize sugar during photosynthesis
2cii)-Magnessium
-Iron
2ciii) Magnessium --->Yellowing of leaves and poor growth
-Iron--->Yellowing of leaves and poor growth
2d) -Take a freshly plucked green leaf and boil it for about 5minutes to kill the cells of the leaf and to burst the starch grains in the cells of the leaf
-Boil the boiled leaf in ethanol to remove the chlorophyll(i.e.decolourizes)
-Dip the decolourized leaf in warm water to soften it
-Wash the leaf in tap water to remove traces of ethanol in it
-Pour iodine solution on it and allow to stand for some minutes
-If the leaf turns blue-black,it contains starch
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6a)
The odorous molecules come into contact with the olfactory epithelium at the top of the nasal cavity and stimulate multiple chemically cell receptors and thus the odour is transmitted to the brain. There after the brain interprets the type of smell.
6b)
i)Shell
ii)Membranes
iii)Airspace
iv)Albumen
v)Yolk
vi)Chalaza
6ci) An autotroph or producer, is an organism that produces complex organic compounds from simple substances present in its surroundings, generally using energy from light or inorganic chemical reactions.
6d)1. Providing leadership on matters critical to health and engaging in partnerships where joint action is needed;
2. Shaping the research agenda and stimulating the generation, translation and dissemination of valuable knowledge;
3. setting norms and standards and promoting and monitoring their implementation;
4. Articulating ethical and evidence-based policy options;
5. Providing technical support, catalysing change, and building sustainable institutional capacity;
6. Monitoring the health situation and addressing health trends