2025 NECO BIOLOGY: Biology (Bio) NECO Authentic Answers 2026 (3139)

(1a)

(i) Calyx

(ii) Corolla

(iii) Androecium

(iv) Gynoecium

(1bi)

(PICK ANY ONE)

Protein digestion in humans starts in the stomach, where hydrochloric acid and an enzyme called pepsin break large protein molecules into smaller pieces called peptides. In the small intestine, enzymes from the pancreas, such as trypsin, chymotrypsin, and carboxypeptidase, continue to break down these peptides into even smaller units. Further digestion happens with the help of enzymes in the intestinal walls, which change the small peptides into amino acids. These amino acids are then absorbed through the villi of the small intestine into the bloodstream and are used by the body to build and repair tissues and for energy when needed.

OR

The digestion of protein in humans begins in the stomach, where hydrochloric acid helps to unfold proteins, and the enzyme pepsin breaks them into smaller pieces called peptides. These peptides then move into the small intestine, where pancreatic enzymes like trypsin and chymotrypsin break them down further. Another enzyme, carboxypeptidase, helps to release amino acids from the peptide chains. Finally, enzymes in the wall of the small intestine complete the digestion, turning the peptides into amino acids. These amino acids are then absorbed into the bloodstream and used by the body for growth, repair, and energy when necessary.

(1bii)

(PICK ANY THREE)

(i) Parenchyma

(ii) Collenchyma

(iii) Sclerenchyma

(iv) Xylem

(v) Phloem

(1ci)

[img]https://i.ibb.co/5x4JygrJ/IMG-20250707-WA0042.jpg[/img]

(1cii)

(PICK ANY THREE)

(i) Enzymes are biological catalysts that speed up the rate of chemical reactions in living organisms.

(ii) They are protein in nature and can be denatured by heat and extreme pH.

(iii) Enzymes are specific in action, meaning each enzyme acts on a particular substrate.

(iv) They are not used up during the reactions they catalyse and can be reused.

(v) Enzymes work best at optimum temperature and pH for maximum activity.

(2bi)

Air Pollutants:

(PICK ANY TWO)

(i) Carbon monoxide

(ii) Sulphur dioxide

(iii) Nitrogen oxides

(iv) Dust particles

Water Pollutants:

(PICK ANY TWO)

(i) Sewage

(ii) Oil spillage

(iii) Dissolved fertilizers

(iv) Heavy metals (e.g., mercury, lead)

(v) Industrial effluents

(vi) Biodegradable waste

(2bii) 

(PICK ANY FOUR)

(i) Marginal placentation

(ii) Axile placentation

(iii) Parietal placentation

(iv) Basal placentation

(v) Free central placentation

(vi) Superficial placentation

(2c) 

(PICK ANY FOUR)

(i) Use of condoms

(ii) Use of oral contraceptive pills

(iii) Use of intrauterine devices (IUD)

(iv) Vasectomy in males

(v) Tubal ligation in females

(vi) Safe period (calendar method)

3a)

During the day, guard cells absorb water by osmosis due to the accumulation of potassium ions, making them turgid and causing the stomatal pore to open. At night or during water shortage, potassium ions leave the guard cells, leading to water loss by osmosis. This makes the guard cells flaccid, causing the stomatal pore to close, thus controlling gas exchange and water loss in the plant.

(3bi) 

(PICK ANY THREE)

(i) Temperature

(ii) Light intensity

(iii) Water availability

(iv) Soil pH

(v) Humidity

(3bii) 

(PICK ANY THREE)

(i) Kidneys

(ii) Lungs

(iii) Skin

(iv) Liver

(v) Large intestine

(3ci) 

(PICK ANY FOUR)

(i) Blinking of the eyes

(ii) Withdrawal of hand from hot objects

(iii) Knee-jerk reflex

(iv) Sneezing

(v) Coughing

(vi) Pupil constriction to bright 'copied from e x a m p l a z a s . c o m free' light

(3cii) 

Chromosomes are regarded as the basis of heredity because they carry genes that determine the inheritable characteristics of organisms. These chromosomes, found in the nucleus, are passed from parents to offspring during reproduction, ensuring the transmission of genetic traits from one generation to another.

(3a)

During the day, guard cells absorb water by osmosis due to the accumulation of potassium ions, making them turgid and causing the stomatal pore to open. At night or during water shortage, potassium ions leave the guard cells, leading to water loss by osmosis. This makes the guard cells flaccid, causing the stomatal pore to close, thus controlling gas exchange and water loss in the plant.

(3bi) 

(PICK ANY THREE)

(i) Temperature

(ii) Light intensity

(iii) Water availability

(iv) Soil pH

(v) Humidity

(3bii) 

(PICK ANY THREE)

(i) Kidneys

(ii) Lungs

(iii) Skin

(iv) Liver

(v) Large intestine

(3ci) 

(PICK ANY FOUR)

(i) Blinking of the eyes

(ii) Withdrawal of hand from hot objects

(iii) Knee-jerk reflex

(iv) Sneezing

(v) Coughing

(vi) Pupil constriction to bright light

(3cii) 

Chromosomes are regarded as the basis of heredity because they carry genes that determine the inheritable characteristics of organisms. These chromosomes, found in the nucleus, are passed from parents to offspring during reproduction, ensuring the transmission of genetic traits from one generation to another.

(4aii)

(PICK ANY ONE)

Hypermetropia, also known as long-sightedness, is an eye defect in which a person can see distant objects clearly but has difficulty seeing near objects clearly. It occurs when the eyeball is too short or the lens is too flat, causing light rays from near objects to be focused behind the retina instead of on it.

OR

Hypermetropia is an eye defect where a person can see distant objects clearly but finds it difficult to see near objects clearly. This defect happens when the image of near objects is formed behind the retina because the eyeball is too short or the lens is not curved enough to focus the light rays properly.

(4bi)

(PICK ANY FOUR)

(i) They are usually brightly coloured to attract insects.

(ii) They often produce nectar to lure insects for pollination.

(iii) They have large, sticky, or rough pollen grains that can attach to insect bodies.

(iv) They possess scented or sweet-smelling flowers to attract insects.

(v) The stigmas are usually sticky to trap pollen brought by insects.

(vi) The anthers are firmly attached  to facilitate pollen transfer by insects.

(4bii)

(PICK ANY FOUR)

(i) Destruction of farmlands and crops.

(ii) Soil erosion and loss of soil fertility.

(iii) 'copied from e x a m p l a z a s . c o m free' Contamination of water sources with pollutants.

(iv) Displacement of people and wildlife from their habitats.

(v) Damage to roads, bridges, and infrastructure.

(vi) Increase in the spread of water-borne diseases.

(4c)

(i) Auxins

(ii) Gibberellins

(iii) Cytokinins

(iv) Abscisic acid

(v) Ethylene

(5bi)

Ribosome:

(PICK ANY ONE)

-They help the cell to make proteins.

-They produce enzymes needed for the cell to work properly.

-They help to repair parts of the cell that are damaged.

Lysosome:

(PICK ANY ONE )

-They help the cell to digest food and other materials inside it.

-They can break down the cell when it dies or is damaged.

-They help to break down and remove waste products in the  

(5bii)

(PICK ANY ONE)

At each trophic level in a food chain, energy is lost due to respiration, movement, excretion, and as heat. Only a small portion of energy (about 10%) is passed on to the next level, while the rest is used up by the organism for its life processes or lost to the environment. This leads to a progressive decrease in the amount of energy available as one moves from producers to herbivores and then to carnivores in the food chain.

OR

There is a progressive decrease in energy transferred along a food chain because organisms use up energy for their metabolic activities such as respiration, growth, movement, and maintaining body temperature. Additionally, some energy is lost as heat to the environment and some as waste materials. As a result, only a small 'copied from e x a m p l a z a s . c o m free' fraction of energy is transferred to the next trophic level, causing a continuous decrease in energy along the food chain.

(5biii)

(PICK ANY TWO)

(i) Presence of a selectively permeable membrane

(ii) Difference in concentration of water molecules on both sides of the membrane.

(iii) The membrane must be thin to allow easy movement of water molecules.

(iv) The system should be in a fluid state (presence of water).

(v) Temperature should be suitable to allow the movement of water molecules.

(5c)

(PICK ANY FIVE)

(i) Crop rotation

(ii) Contour ploughing

(iii) Terracing

(iv) Planting cover crops

(v) Afforestation

(vi) Strip cropping

(vii) Mulching

(viii) Controlled grazing