WAEC 2017/2018 Verified Complete Biology free answers, Objectives/essay and theory Expo runz runs now posted for Free.

*BIOLOGY ANSWERS*

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) -Whensource: naijacomms.com 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 aresource: naijacomms.com 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: naijacomms.com burst the starch grains in the cells of the leaf
-Boil source: naijacomms.com 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 intosource: naijacomms.com 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 source: naijacomms.com 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)

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THEORY
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Section B Answer 3 Only
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1ai)
Classification of living things is the way in which all living things are placed into larger and larger groups or catetories that share similarities and a common ancestry.
1aii)
Carl Linnaeus
1aiii)
i)It allows scientists to identify, group, and properly name organisms via a standardized system
ii)to make it easier to study and understand their behaviors,
iii)To study evolutionary progression of millions of life forms
1aiv)
i)Kingdoms
ii)Phylum
iii)Classes
iv)Order
v)Families
vi)Genus
vii)Species
1bi)
i)they can reproduce
ii)they can mutate
1bii)
i)they do not carry out metabolism on their own hence they do not grow
ii)they contain no cytoplasm or cellular organelles
1ci)
i)mosaic disease of cassava
ii)swollen shoot disease of cocoa
1cii)
i)human immunodeficiency virus (HIV)
ii)measles
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