Neco 2023 Biology Essay & Objective Answers


Neco June/July 2023 Biology Essay & Objective Answers

 

 

BIOLOGY OBJ

1-10: BBEDACCAEE
11-20: DDCEADBAED
21-30: EBBBEADBDD
31-40: EDACCCBCEA
41-50: EBBCACBAEC
51-60: DDABEDDDBE

COMPLETED
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INSTRUCTION; ANSWER THREE(3) QUESTIONS ONLY

(1ai) The cell theory states that:
– All living organisms are made up of one or more cells.
– The cell is the basic unit of life.
– All cells arise from pre-existing cells.

(1aii)
– Robert Hooke, who discovered cells in 1665 and coined the term “cell”.
– Matthias Schleiden and Theodor Schwann, who proposed the cell theory in 1839-1840.

(1bi)
– Large, brightly colored petals that attract insects.
– Nectar-producing glands to feed the insects.
– A strong, sweet fragrance to attract the insects.
– A landing platform for the insects to rest on.
– Pollen that is sticky and easily attaches to the insects.

(1bii)
– Ginger: Rhizome
– Banana: Rhizome
– Sweet potato: Tuber

(1c)
– The mouth mechanically breaks down the bread by chewing and mixes it with saliva, which contains enzymes that begin breaking down the carbohydrates in the bread.
– The esophagus moves the food down to the stomach, where it is mixed with stomach acid and enzymes that further break down the bread.
– The small intestine absorbs the nutrients from the bread, such as carbohydrates, proteins, and fats, into the bloodstream.
– The large intestine absorbs water and electrolytes from the remaining food waste, forming feces.
– The rectum stores feces until they can be eliminated through the anus.
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(2ai)
Amoeba > Hydra > Tilapia > Toad > Snake

(2aii)
(i) Small, lightweight seeds that can be easily carried by the wind.
(ii) Hairs or wings on the fruit that increase surface area and help to catch the wind.
(iii) A dry, papery fruit that splits open easily to release the seeds.

(2b)
=Aim:=
To determine if the shoot of a plant is positively phototropic.

=Apparatus:=
A potted plant, a light source, a ruler, a marker.

=Method/Procedure:=
(i) Place the plant in a dark room for 24 hours to ensure that it is not positively or negatively phototropic.
(ii) Place the light source at a fixed distance from the plant, with the light shining directly on the plant’s shoot.
(iii) Turn on the light source and leave it on for 24 hours.
(iv) After 24 hours, measure the distance between the tip of the shoot and the light source.
(v) Mark the new position of the shoot tip on the ruler.
(vi) Repeat the experiment two more times, moving the light source to a different position each time.

=Observation:=
The shoot of the plant will grow towards them light source, bending in the direction of the light.

=Conclusion:=
The shoot of a plant is positively phototropic and grows towards a light source.

(2c)
[TABULATE]

=Aerobic Respiration=
(i) Occurs in the presence of oxygen
(ii) Produces a large amount of ATP
(iii) Carbon dioxide and water are produced as waste products

=Anaerobic Respiration=
(i) Occurs in the absence of oxygen
(ii) Produces a small amount of ATP
(iii) Lactic acid or ethanol is produced as a waste product

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(3ai)
– Rivers
– Lakes

(3aii)
TABULATE

=Complete Metamorphosis=
(i) Four distinct stages: egg, larva, pupa, adult.
(ii) Larva looks completely different from the adult.

=Incomplete Metamorphosis=
(i) Three stages: egg, nymph, adult.
(ii) Nymph looks similar to the adult, just smaller.

(3b)
– Aim: To determine if chlorophyll is necessary for photosynthesis to take place.

– Apparatus: Two plants of the same species, one with leaves covered in aluminum foil, a light source, test tube, water, and a beaker.

– Method/procedure: Place one plant in a dark room and cover its leaves with aluminum foil. Place the other plant in front of a light source. After a few hours, pluck a leaf from each plant and place them in separate test tubes filled with water. Place the test tubes in a beaker and keep them in the dark.

– Observation: After a few hours, observe the test tubes to see which one has produced more oxygen bubbles.

– Conclusion: If the test tube with the leaf from the plant exposed to light produces more oxygen bubbles, then chlorophyll is necessary for photosynthesis to take place.

(3ci)
(i) Overuse of synthetic fertilizers
(ii) Overgrazing
(iii) Deforestation
(iv) Soil erosion

(3cii)
(i) Hearing loss
(ii) Sleep disturbance
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(4ai)
(PICK ANY THREE)
(i) The crops with tap roots should be followed by those with fibrous root system.
(ii) Selection of the crop should be demand based.
(iii) The selection of crops should be problem based.
(iv) The selection of crops should suit to the farmer’s financial conditions.
(v) More exhaustive crops should be followed by less exhaustive crops.
(vi) The crops selected should also suit to the soil and climate conditions.
(vi) The crops selected should also suit to the soil and climate conditions.

(4aii)
(PICK ANY FIVE)
(i) The presence of thick, waxy cuticles on leaves:
(ii) Stomata present in the upper epidermis only:
(iii) Shrinking of hinge cells when flaccid:
(iv) Flashy succulent leaves:
(v) Have reduced number of stomata:
(vi) Sunken stomata or presence of crypts and leaf surface covered with fine hairs.
(vii) Closed stomata in the presence of light and opened stomata in the absence of light:
(viii) Leaves are reduced to spines, needles, or scales and they are folded or rolled when flaccid

(4bi)
(i) Feathers : Feathers are modified scales that provide insulation and enable flight in birds. Some fossil reptiles, such as Archaeopteryx and Microraptor, also had feathers, suggesting that they were an ancestral trait that evolved before the divergence of birds and reptiles.
(ii) Bones : Birds have hollow bones that reduce their weight and enhance their flight ability. Some fossil reptiles, such as Coelophysis and Pterosaurs, also had hollow bones, indicating that they were an adaptation to a fast and agile lifestyle.
(iii) Eggs : Birds lay hard-shelled eggs that protect their embryos from dehydration and predation. Reptiles also lay hard-shelled eggs, implying that they share a common reproductive strategy that originated in their ancient ancestors.

(4bii)
(PICK ANY FIVE)
(i) Regulates amino acids.
((ii) Regulates blood clothing
(iii) Stores Vitamins and Minerals.
(iv) Processes glucose
(v) Filters blood
(vi) Bile production
(vii) Albumin production
(viii) Resists infections.

(4c)
(PICK ANY FOUR)
(i) Reforestation.
(ii) Afforestation
(iii) Protect Existing Forests.
(iv) Sustained Yield Method.
(v) Produce Less Waste
(vi) Monitor Agriculture
(vii) Planned and Regulated Tree-cutting
(viii) Laws and Rules Help Prevent Deforestation.

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(5a)
DIAGRAM

(5bi)
(i) Protection: the calyx protects the flower bud before it opens and the developing fruit after fertilization.
(ii) Support: the sepals of the calyx can provide support for the petals and reproductive structures.

(5bii)
(i) Insulin: regulates blood sugar levels.
(ii) Estrogen: regulates female reproductive system and secondary sexual characteristics.
(iii) Testosterone: regulates male reproductive system and secondary sexual characteristics.
(iv) Adrenaline: prepares the body for “fight or flight” response to stress.
(v) Melatonin: regulates sleep-wake cycles.

(5ci)
(i) Gene therapy: correcting genetic disorders by introducing functional genes into the patient’s cells.
(ii) Predictive medicine: using genetic testing to identify individuals who are at risk for certain diseases and develop personalized prevention or treatment plans.

(5cii)
(i) Large surface area: to maximize light absorption.
(ii) Thin and flat shape: to reduce the distance that light needs to penetrate into the leaf.
(iii) Chlorophyll pigments: to absorb light energy and convert it into chemical energy.

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