2016 Waec gce Biology Essay and obj Expo

2016 WAEC GCE CERTIFIED BIOLOGY OBJECTIVES

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We lead while others follow






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6c)
i)It reduces the quality and quantity of the crops
ii)it reduces their productivity

6d)
i)by refrigerating
ii)by salting
iii)by drying
iv)by the use of silos

6e)
i)in medicine
ii)in crime detection

6f)
i)Inadequate resources
ii)Small planting space
iii)

6g)
Succession is the change in either species
composition, structure, or architecture of
vegetation through time.

6h)
i)it kills microorganisms
ii)It leads to soil erosion
iii)It lost of soil nutrients







Question 2

Ai) Enzymes are organic catalysts which are responsible for breaking complex food substances taken by animals into simple, soluble and diffusible substances before they can be absorbed into the body



Aii) Enzymes have the following characteristics;

i] Enzymes are soluble
ii] Enzymes are sensitive to the acidity or alkalinity of their environment
iii] Enzymes are sensitive to temperature
iv] Enzymes are organic catalysts which speed up chemical reactions
v]Enzymes are inactivated by inhibitors


B) The pancreatic juice is a watery alkaline liquid containing three important digestive enzymes.One of them, Amylopsin breaks down starch ( a carbohydrate) to maltose. Another, Trypsin , breaks down proteins to polypeptides


C)Milk contains calcium which forms and maintains strong bones. Also, when exposed to sunlight, the skin produces vitamin D whose major role is to maintain normal blood levels of calcium and phosphorus in the body. Vitamin D helps the body absorb calcium to improve bone health


D) Importance of photosynthesis

i) It is the only process that can tap the sun's enormous energy supply

ii)It helps to purify the environment by removing carbon dioxide from the environment

iii) It helps to add oxygen to the environment

iv)Plant products like timber, rubber, herbs , medicines are derived from photosynthesis

v) Rare fossil fuels like coal, petroleum and natural gas are formed through the degradation of the past plant and animal parts, which were initially formed from photosynthesis


QUESTION 6

Ai) Mimicry is the act of a harmless animal resembling dangerous one. An insect which is harmless may resemble a well-known dangerous wasp and hence avoid being killed by predators.
Example: A south African stone plant grows in regions and bears leaves that resemble stones so closely that herbivores will not eat them

ii) Camouflage is an adaptation, normally of form and colour, that helps an organism to blend with its surroundings so that it is not easily detected.
Example: Certain caterpillars and insects look like leaves and twigs of the plant on which they feed

Bi) Legs adapted for running

ii) Evolved mandibles for biting and chewing solid food

iii)Have flora that help them survive by handling nitrogen metabolism and sulfate reduction
.
6c)
i)It reduces the quality and quantity of the crops
ii)it reduces their productivity

6d)
i)by refrigerating
ii)by salting
iii)by drying
iv)by the use of silos

6e)
i)in medicine
ii)in crime detection

6f)
i)Inadequate resources
ii)Small planting space
iii)

6g)
Succession is the change in either species
composition, structure, or architecture of
vegetation through time.

6h)
i)it kills microorganisms
ii)It leads to soil erosion
iii)It lost of soil nutrients