2025 NECO BIOLOGY: 2025 NECO BIOLOGY ANSWERS (6681)

(1a)

(i) To search for food.

(ii) Escape predators.

(iii) Find mates for reproduction.

(iv) To disperse/reduce competition/overcrowding by moving to new locations.

(1bi)

Phloem: Responsible for the transportation of enzymes/hormones.

(1bii)

Leaf: is used for photosynthesis

(1biii)

Xylem; is to transport water from roots to stems and leave

(1biv)

Flower; is for reproduction in plant

(1ci)

(i)Low water requirements

(ii)No leaves or small number of leaves

(iii)Possession of thorn or needles

(1cii)

(i)it provides new cells for growth

(ii)for replacement of worn-out cells

(1di)

An image is formed on the retina with light rays converging most at the cornea and upon entering and exiting the lens. Rays from the top and bottom of the object are traced and produce an inverted real image on the retina. The distance to the object is drawn smaller than scale.

(1dii)

(i)Evidences from Palaeontology

(ii)Evidences from Comparative Morphology

(iii)Evidences from taxonomy

(1a)

Animals move from one place to another:

(i) In search of food.

(ii) In search of mates.

(iii) In search of shelter.

(iv) To escape from enemies or predators.

(1b)

(i) Phloem conducts food substances downward to other tissues in the root of plants.

(ii) Lead helps plants to transpire and undergo photosynthesis.

(iii) Xylem transports water and dissolved mineral salts upwards through the vascular bundle.

(iv) The primary function of a flower is for reproduction

(1ci)

(i) Small or no leaves to prevent evaporation.

(ii) Thorns for protection against animals seeking stored water.

(iii) Ability to quickly absorb water whenever available.

(1cii)

(i) It ensures that the diploid condition of the cell is retained from generation to generation.

(ii) As cells undergo miotic division, growth occurs.

(1di)

Light rays from an object enter the eye through the cornea. The light rays are refracted by the convex cornea and passed through the aqueous humor which further bends the light rays before entering the lens through the pupil. The lens further bends the light rays and focuses them on the retina.

The light are converted into electrical impulses which are sent through the optic nerve to the optic lobes of the brain where they are correctly interpreted.

(1dii)

(i) Evidence from comparative 'copied from e x p o c o d e . n e t free' anatomy

(ii) Evidence from vestigial organs.

(iii) Evidence from fossils.

(2a)
(i)Eye lids
(ii)Conjunctiva

(2bi)
Excretion is the removal of waste products of metabolism which are harmful or would in time interfere with the normal functions of the organisms

(2bii)
Competition is an interaction between a number of the organisms of the same or different species for resources in limited supply such as food, water , space and light

(2biii)
Deforestation is the extensive cutting down of trees for the purpose of either farming it firewood or mining thereby exposing the top soil to agents of erosion

(2c)


(2d)
(i)Refrigeration
(ii)Canning
(iii)Dehydration or drying of foods
(iv)Pasteurization

(2a)
(i) Bony sockets
(ii) Eye brows

(2bi)
Excretion is the removal of waste products of metabolism which are harmful or would in time interfere with 'copied from e x p o c o d e . n e t free' normal functions of organisms.

(2bii)
Competition is a biological interaction between organisms of the same species or different species for the same resources which are in limited supply such as food, space or mates.

(2biii)
Deforestation is the cutting down of forest trees on 'copied from e x p o c o d e . n e t free' a land.

(2c)


(2d)
(i) Canning
(ii) Refrigeration
(iii) Dehydration
(iv) Pasteurization

(3a)
(i) Meiosis : four daughter cells
(ii) Mitosis: two identical daughter cells

(3bi)
(i)It reduces the risk of diseases from parents to offsprings
(ii)It create diversity and variation among populations

(3bii)
The relationship is known as commensalism in which the remora fish gains while he shark neither gain nor loose. In this case, the remora fish attach itself to the shark which transport it round the water protecting it form predators and it also obtain it's food through the process. The shark on the other hand neither gain or loose.

(3ci)
(i)High fever
(ii)Sore throat
(iii)dry cough

(3cii)
It carries filtered blood from the kidney's to the posterior vena cava

(3di)
Ecological niche: This is the exact position by an organism in a particular habitat

(3dii)
Population density: This can be defined as the total number of organism per unit area of the habitat

(3diii)
Climax community: This is established when a stable or unchanging community is attained, thus the community is in equilibrium with the environment

(3a)

(i) Meiosis - Four daughter cells.

(ii) Mitosis - Two daughter cells.

(3bi)

(i) It permits variability of individuals, which enhances survival in new environment.

(ii) It permits new species formation.

(iii) It permits the production of hybrids for some desirable traits.

(3bii) 

The relationship between Remora and Shark is commensalism. Remora attaches itself to the underside of a shark and feeds on scraps of shark's food. The shark neither benefits nor suffers in any respect.

(3ci) 

Symptoms of covid-19 are:

[Pick Any Three]

(i) Fever

(ii) Dry cough

(iii) Tiredness

(iv) Difficulty in breathing.

(3cii) 

Renal vein carries blood from the kidney to the inferior vena cava. 

(3di) 

Ecological niche at a species refers to its life style, how it lives, what it does, or how it interacts with other members of its habitat.

(3dii) 

Population density is the member of individuals per unit area or volume at a particular time eg the number of human inhabitants per square kilometre.

(3diii)

A climax community  the final stage of biotic succession attainable by a plant community in an area under the environmental conditions present at a particular time. The species composition of the climax community remains the same because all the species present successfully 'copied from e x p o c o d e . n e t free' reproduce themselves and invading species fail to gain a foothold.

(4ai)

Aestivation is the mode of arrangement of sepals or petals in the floral bud with respect to the other members of the same whorl.

(4aii)

(i)Nose for smelling

(ii)Eyes for seeing

(iii)Tongue for tasting

(iv)Ear for hearing

(4aiii)

When a person spin around rapidly, that liquid in the inner ear spins as well. When the person stops spinning the liquid keeps moving for a bit, confusing your brain into thinking that the person is still spinning even when the person is standing still and that causes the feeling dizziness after spinning around the stationary object.

(4bi)

Neuron; transmit information to other nerve cells, muscle, or gland cells.

(4bii)

cerebrum; initiates and coordinates movement and regulates temperature

(4biii)

Mendulla Oblongata; passes messages between your spinal cord and brain.

(4biv)

cerebellum; coordinates voluntary movements

(4ci)

Tabulate;

(i)tropic the effect is more or less permanent while Nastic movements are temporary and reversible.

(ii)Stimuli for the tropic movements are unidirectional and never diffuse while The stimuli for the Nastic movements may be unidirection or diffuse.

(iii)Movement in tropic movements is directional while Nastic movements is non directional

(4cii)

(i)Contains chlorophyll 'copied from e x p o c o d e . n e t free' Absorbs light

(ii)Stomata Allows carbon dioxide to move by diffusion into the leaf

(iii)Guard cells To open and close the stomata depending on the conditions