2014 JAMB BIOLOGY PAST QUESTIONS AND ANSWERS

This question checks the candidate’s ability to identify the specific type of the examination paper they received, ensuring that they are aware of their paper version. This is important in exams with multiple versions to avoid confusion and ensure accurate scoring.

Part II in the diagram represents the nucleus, a critical cell organelle responsible for controlling cellular activities and housing genetic material. The other options include the eyespot, which detects light, the basal granule that supports flagella, and the contractile vacuole that regulates water balance, particularly in unicellular organisms.

The part labeled I is responsible for photosynthesis. This part likely represents chloroplasts or similar structures involved in converting light energy into chemical energy through photosynthesis. This function is crucial for autotrophic organisms like plants and algae. Other structures would not have this function as they do not contain chlorophyll.

The lowest level of organization in living organisms is the cell, which is the basic unit of life. Organ systems, tissues, and organs are higher levels of biological organization that involve multiple cells working together to perform complex functions.

The heart, as an organ composed of tissues, is the most complex among the options, having multiple types of cells organized into tissues and performing coordinated functions. Hair, by contrast, is a simpler structure composed mostly of protein without complex cellular organization.

The structures labeled II and III in the diagram represent the attachment organs (such as hooks or suckers) that help parasites attach to the host’s intestinal wall, preventing them from being dislodged by peristalsis. This adaptation is common in parasitic organisms like tapeworms.

The part labeled IV represents a young proglottid. In tapeworms, proglottids are segments that contain reproductive organs. The youngest segments are located near the neck, while mature proglottids are found further down.

Spirogyra is a multicellular organism, while organisms like Chlamydomonas, Amoeba, and Euglena are unicellular. Spirogyra, a green algae, consists of long filaments of cells that can perform photosynthesis, making it distinctively multicellular compared to other protists.

The gametophyte is the sexual phase in the life cycle of bryophytes, where sex organs develop. The sporophyte stage, in contrast, is non-sexual and produces spores. Protonema is the initial growth form in bryophytes, and rhizoid helps in attachment.

Efficient seed dispersal allows seed plants to spread and occupy diverse habitats. This adaptability contributes to their dominance. Photosynthesis, while essential, is common to all plants, and motile gametes and water availability are less relevant for seed plant dominance on land.

Birds are arboreal organisms as they primarily live in trees. Elephants, fish, and antelopes are terrestrial or aquatic and do not have the adaptations necessary for an arboreal lifestyle.

The part labeled I represents the xylem, which is responsible for the transport of water and nutrients in vascular plants. Phloem transports food, cortex is involved in storage, and root hairs increase surface area for water absorption.

The diagram represents a monocotyledonous stem. This is evident from the arrangement of vascular bundles, which are scattered throughout, unlike in dicotyledonous stems where they are arranged in a ring.

The formula represents the dental formula of a herbivore. Herbivores typically have teeth suited for grinding plant material, with a lack of canines (c 0/0) and the presence of large molars for chewing. Carnivores, omnivores, and detritus feeders have different dental structures.

Diffusion is sufficient for smaller organisms like Amoeba to transport materials due to their small size and simple structure. Mammals, being more complex and larger, require a circulatory system to distribute nutrients and oxygen efficiently.

Sieve tubes and companion cells are found in the phloem, which transports food from leaves to other parts of the plant. The xylem, cortex, and cambium serve different functions in vascular plants.

The spiracle of insects serves a similar function to stomata in leaves, allowing gas exchange with the environment. Humans’ pharynx, fish scales, and toad trachea do not serve this function.

Cutaneous respiration involves gas exchange through the skin, common in amphibians. Cellular respiration occurs at the cellular level, buccal respiration uses the mouth cavity, and pulmonary respiration occurs in the lungs.

Transpiration is the process through which water is lost as vapor from plant leaves, primarily through stomata. Diffusion, osmosis, and evaporation involve movement of substances but not specifically the water loss from plants.

Rhizomes are organs of perennation, allowing plants to survive unfavorable conditions. Seeds also serve this purpose, while petals and calyx are parts of flowers that do not contribute to perennation.

Mosses exhibit alternation of generations, with distinct gametophyte and sporophyte stages. Fungi, grasses, and conifers do not show this pattern.

Plants grow primarily at the apical meristems, and their growth is generally indefinite. This characteristic differs from animals, whose growth is often determinate.

The nervous and endocrine systems work together to coordinate body activities. Muscles act as effectors rather than regulators, while nerves alone or hormones alone do not suffice for complete regulation.

The cerebellum is responsible for coordinating muscular activity, particularly balance and movement. Reflex actions, emotional expressions, and endocrine control are managed by other brain parts.

The medulla oblongata regulates involuntary actions like peristalsis. Other brain parts, such as the olfactory lobe, hypothalamus, and thalamus, are involved in different functions.

A barometer measures atmospheric pressure, while hydrometers, hygrometers, and thermometers measure other environmental factors.

Edaphic factors refer to the influence of soil characteristics on organisms. Physiographic relates to physical features, biotic to living organisms, and topographic to land forms.

Genotype refers to the genetic constitution of an organism, while allele, chromosome, and phenotype are specific genetic components or expressions.

Sunlight is crucial in aquatic habitats, especially for photosynthesis. Food, temperature, and water availability also impact productivity but to a lesser extent.

Tropical rainforests are known for their high biodiversity, containing a large number of plant species. This biome typically has high rainfall (usually more than 200 cm annually), contrary to having less than 50 cm. Trees in this region generally have broad leaves to maximize photosynthesis, not narrow leaves.

Population dynamics is the field that investigates the changes in population size and composition over time, along with the factors influencing these changes. Population ecology studies populations within ecosystems, while estimation and cycle focus on different aspects of population analysis.

The Sahel Savanna experiences prolonged dry seasons, with minimal rainfall, adapting flora and fauna to survive with little water. Mangrove swamps, Sudan, and Guinea Savanna regions experience varying rainfall patterns but do not have such severe dry periods.

Anabaena is a nitrogen-fixing blue-green algae (cyanobacteria) found in soil. Other options like Rhizobium and Clostridium are nitrogen-fixing bacteria, not algae, and Nitrosomonas is involved in nitrification.

Clayey soil has the highest water retention capacity due to its fine particles and low permeability. Sandy soil has low water retention, stony soil drains easily, and loamy soil has moderate water-holding capacity.

Poliomyelitis, also known as polio, is caused by a virus. Bacteria, fungi, and protozoans cause other diseases but are not responsible for polio.

Siting industries away from residential areas helps reduce noise pollution exposure. Combustion, planting trees, and wearing ear devices have other environmental or individual benefits but are less effective as a systemic solution for noise reduction.

Carbon monoxide (CO) is a major pollutant in exhaust fumes and can be harmful when inhaled. Other options like water vapor are non-toxic, while carbon dioxide and ozone are present but less immediately harmful compared to CO.

Smallpox is a viral disease that can be controlled through vaccination. It is not caused by bacteria, cannot be treated with antibiotics, and is not water-borne.

Nitrogen oxides, particularly NO₂, contribute to acid rain by forming nitric acid in the atmosphere. Ozone and fluorine are not major contributors, and carbon monoxide is unrelated to acid rain.

In Paramecium, when conditions are unfavorable or individuals are weakened, binary fission is replaced by conjugation, a form of sexual reproduction. Euglena, Amoeba, and Plasmodium do not use this method as an alternative to binary fission.

Fingerprint patterns are categorized into whorls, arches, loops, and compounds. Hair color, blood groups, and body color do not have these pattern types.

The sex determination was due to the man’s Y chromosome. In humans, it is the presence of a Y chromosome in sperm that determines male offspring; without it, offspring are female.

Interferon is a protein produced by cells in response to viral infections, helping to inhibit virus replication. Enzymes, antibiotics, and disinfectants do not have specific antiviral properties.

Outbreeding increases genetic diversity, which can improve disease resistance among offspring. Pests tolerance, growth rate, and height may improve but are not direct outcomes of outbreeding.

Blood group AB is the universal recipient, meaning individuals with this blood type can receive blood from A, B, AB, and O groups.

A streamlined body shape allows fish to move easily through water, reducing resistance. This adaptation is crucial for efficient movement rather than securing mates, feeding, or defense.

A lizard is a poikilothermic (cold-blooded) organism, meaning its body temperature varies with the environment. Mammals like rabbits and birds are homeothermic (warm-blooded).

Charles Darwin proposed the concept of the “struggle for existence” as part of his theory of natural selection. Lamarck, Wallace, and Morgan contributed other evolutionary ideas.

Adaptive radiation is shown by the modified insect mouthparts, where different species adapt their feeding structures to various diets. Mammalian dentition and wing evolution are also examples, but insect mouthparts are the clearest case.