Waec 2017 Biology Answers Essay/Obj Now Posted

Biology 2 (Essay) 2.00pm. – 3.40pm
Biology 1 (Objective) 3.40pm – 4.30pm




BIOLOGY OBJ

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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)

i)mosaic disease of cassava
ii)swollen shoot disease of cocoa


1cii)

i)human immunodeficiency virus (HIV)
ii)measles


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.
iv)They aid in metabolism(anabolism and catabolism)


2bi)

-Pancreatic lipase
-Amylase



2bii)

i)maltae act
ii)lipase act
2bii)

i)it converts fat and oil to fatty acids and glycerol
ii)it converts starch to maltose
2ci)

Chlorophyll is necessary to absorb the radiant energy of the sun to synthesize sugar during photosynthesis 2cii)

i)Magnessium
ii)Iron

2ciii)

i)Magnessium —}Yellowing of leaves and poor growth
ii)Iron—}Yellowing of leaves and poor growth


2d)

-boil the leave to kill the leaves,inactivate the enzymes and burst starch grains.

-Dry in 70% alcohol to decolourise the leave

-Dry the leaf in hot water to soften it

-place on a whole tile and add few drop of iodine solution

-the leave turns blue-black if starch is present



3ai)

Tullgren funnel
3aii)

3C)

Commensalism
Parasitism
Mutualism



3 i) Commensalism is a type of relationship where one of the organisms benefits greatly from the symbiosis. The other is not helped but is not harmed or damaged from the relationship. In other words, this is a one-sided symbiotic relationship.


3 ii) In parasitism, one organism benefits from the relationship but at the expense of the other. The organism may live inside the other’s body or on its surface.
In some of these parasitic relationships the host dies and in others, it is important that the host remain alive.



3 iii) Parasitism
In parasitism, one organism benefits from the relationship but at the expense of the other. The organism may live inside the other’s body or on its surface. In some of these parasitic relationships



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.



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)

autotrophs are organisms that can synthesizes food from inorganic substances by using chemical energy or light


6cii)

i)Bacteria
ii)Unicellular algae
6d)

i)providing leadership on matters critical to health
ii)shaping the research agenda and stimulating the generation
iii)translation and dissemination of valuable knowledge
iv)setting norms and standards
v)promoting and monitoring their implementation
6e)

i)plants: Water Wisteria and Java Moss
. ii)Animals: catfish and earthworm
6f)


In tabular form

-Mammalian skin-
i)It has melanin
ii)It has sweat pores
iii)Does not show photosynthesis
iv)It composes of animal cells
v)It is touch receptive



-Plant epidermis-
i)It has chlorophyll
ii)It has stomata
iii)It shows photosynthesis
iv)It is composed of plant cells
v)It is not touch receptive
6gi)

i)Intra specific competition


6gii)

i)Inter specific competition

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