2017/2018 WAEC Biology Answer

Here is the 2017/2018 WAEC Biology Answer.


OBJ:
1-11:     ABDBCDCBBD
11-20:   DBDCBBABA
21-30:   CBCCDBCDDC
31-40:   CBAADCCABA
41-50:   CABADDDBDC



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) 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


2a)i They catalyse reactions by lowering the activation energy of a reaction
ii). They 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 source: burst the starch grains in the cells of the leaf
-Boil source: 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.


6a)
The odorous molecules come 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 source. surroundings, generally using energy from light or inorganic chemical reactions.

6cii) -Algae
-Green plants

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.

6e) Plants —>Water lettuce
-->Sword grass
Animals —>Tadpole
——>Crayfish

6f)
Tabulate:

Skin of mamma:
-Epidemis is multi-layered
-Waterproof
-Opeque
Epidemis of leaf:
-Epidemis is single layered
-Forous water can seep through
-Transparent

6gi) -Plot A-Since the maize are all same species equal competitions of nutrients would take place(Intra species or intra specific competition).

6gii)Plot B-They are of different species so the maize will highly compete with the pepper on nutrient and sunlight(Inter species or inter specific competition)


4a)draw the diagram between mother and father,under it write their possible blood group of the father are blood group A,Bor O.

4bi)
-Adaptive colouration
-Adaptive behaviour.

4bii)
-in order to invite are another for food or mate
-in order toalert or prevent one another against threat to life.




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