2017 BIOLOGY THEORY ANSWERS

*WAEC 💯 VERIFIED BIOLOGY ANSWERS* 💯💯💯💯✅✅✅✅

*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) -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) *STEPS TO TEST PRESENCE OF STARCH IN THE LEAF*

1. Boil pieces of leaves in a beaker of water TO KILL THE CELLS AND BREAK THE WALL OF LEAF CELL
Fresh leaves
Boiling the leaves
2. Heat the pieces of leaf in alcohol for few minutes TO REMOVE CHLOROPHYLL
Alcohol turns to green color- chlorophyll is removed
3. Soak the pieces of leaf in hot water for a little while TO SOFTEN THE LEAF

4. Using a dropper, add a few drops of iodine solution onto the pieces of leaf TO TEST FOR STARCH

Finally, LEAVES THAT CONTAINS STARCH TURN TO DARK BLUE COLOUR

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
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3ai)Organisms can be collected using a variety of methods, which are:

    Nets and pooters
    Pitfall traps
    Quadrats

Nets and pooters

Nets are useful for collecting flying insects such as butterflies and moths. A pooter is a small jar used for collecting insects. It has two tubes: one goes into your mouth so you can apply suction, and the other goes over the insect so that is sucked into the jar. A fine mesh over the end of the first tube stops you swallowing the insect.
Pitfall traps

A pitfall trap

A pitfall trap is often used to sample small invertebrates living on the ground, such as beetles, spiders and slugs. It consists of a container, such as a yogurt carton, buried in the ground with its top level with the soil surface. The top of the container is covered by a piece of wood with a slight gap to allow insects to climb in. It is important to check the trap regularly to avoid the animals escaping or being eaten before they are counted.


Quadrat

A quadrat is usually a square made of wire. It may contain further wires to mark off smaller areas inside, such as 5 x 5 or 10 x 10 squares. The organisms underneath, usually plants, can be identified and counted.

Quadrats may also be used for slow-moving animals such as slugs and snails.
3aii)Insect net

You can buy insect nets from a biological supply company or from a hobby shop. There are two basic kinds of nets — aerial nets and sweep nets. The lighter bag on an aerial net is designed to capture insects in flight or at rest. The heavier bag on a sweep net is designed to collect insects in tall grass or shrubs by sweeping or beating through the plant