JAMB Biology 2013
Questions & Answers

Options like A or D might seem correct because plants and some microbes make their own food, but fungi lack chlorophyll. Rhizopus, a fungus, feeds saprophytically by absorbing nutrients from dead organic matter instead of manufacturing them internally. Common mistake: Assuming all non-animal organisms are capable of photosynthesis.

Students might mistakenly pick option C, forgetting that it is an overarching term for all chemical processes in the body. Catabolism involves breaking down complex molecules into simpler ones, releasing energy, whereas the opposite building phase stores it. Common mistake: Confusing overall metabolism with the specific breakdown phase.

Option A might look correct because flagella are prominent structures on this organism, but they serve locomotion rather than sensation. The eyespot helps Euglena detect light for phototaxis, guiding movement toward light so it can survive. Common mistake: Attributing sensory functions to locomotory organelles.

Options like A or C list structures involved in waste processing or cell division, making them incorrect for energy conversion. Mitochondria produce energy via respiration, and chloroplasts perform photosynthesis in plant cells, making both indispensable for metabolic energy flow. Common mistake: Confusing synthetic or digestive organelles with energy-transforming ones.

Option A or D might be guessed because humans consume various livestock, but parasitic life cycles have specific primary or intermediate hosts. Pigs are the intermediate hosts for Taenia solium, harboring its larval stage before it reaches human consumers of pork. Common mistake: Mixing up the specific livestock host associated with pork tapeworm transmission.

Options like A or B might seem like normal soil types, but sandy or heavy clay soils lack the necessary organic decay. Humus-rich soils provide nutrients and moisture, ideal for earthworm survival and burrowing habits. Common mistake: Assuming earthworms thrive equally in any mineral soil type.

Option A might seem plausible if a student thinks of soft-bodied larvae, but adult arthropods possess a hard exoskeleton. Arthropods have jointed appendages, such as legs and antennae, for movement, which separates them from unsegmented or soft groups. Common mistake: Overlooking the defining presence of segmented limbs in favor of body softness.

Students might swap the behaviors and select option A for moths or vice versa, so visual memory is key. Butterflies fold wings horizontally at rest, while moths spread wings vertically or flat depending on the species, creating a clear postural difference. Common mistake: Reversing the resting wing positions of butterflies and moths.

Option A or B might be chosen because birds are covered in soft plumage, but those layers insulate rather than generate lift. Quill feathers, or flight feathers, provide lift and control during bird flight due to their strong, rigid structure. Common mistake: Confusing down feathers used for warmth with quill feathers used for flight.

Option A or B might seem correct for plants needing water or moderate conditions, but desert climates are extreme. Xerophytes have adaptations like reduced leaves to survive in dry deserts by minimizing water loss. Common mistake: Confusing plants adapted to water-scarce biomes with moisture-loving hydrophytes.

Option A or C might seem basic because they are single-celled protozoa, but they still possess complete cellular machinery. Viruses lack cellular structure and replicate only within a host, making them simpler than true cellular organisms. Common mistake: Believing single-celled protozoa are simpler than acellular infectious particles.

Option A might be selected because molluscs have varied feeding organs, but a true coiled feeding tube is characteristic of a different group. Insects like butterflies use a proboscis for feeding on nectar, extending it when gathering food. Common mistake: Associating mouthpart adaptations of Lepidoptera with molluscan anatomy.

Option A or D might look correct if thinking of waterfowl or wading birds, but sharp claws serve a predatory function. Talons in birds like hawks are adapted for grasping and holding prey securely during hunts. Common mistake: Confusing webbed or flat feet with predatory talons.

Option A, C, or D might tempt students because they are well-known microbes, but those rely on chemical energy rather than light. Anabaena, a cyanobacterium, uses sunlight for photosynthesis, performing autotrophic nutrition via solar energy. Common mistake: Confusing chemosynthetic bacteria with photosynthetic cyanobacteria.

Option A, B, or D might seem correct because water movement relies on them, but dissolved foods require a specialized vascular pathway. Translocation moves sugars and nutrients through the phloem in plants from source to sink regions. Common mistake: Confusing water transport mechanisms with the movement of manufactured organic nutrients.

Option A or C might be chosen because they are famous digestive enzymes, but they target proteins or fats instead of carbohydrates. Ptyalin (salivary amylase) breaks down starches into sugars in the mouth, initiating carbohydrate digestion early in the digestive tract. Common mistake: Mixing up protein-digesting enzymes with starch-digesting ptyalin.

A student might mistakenly choose parasitic because these plants feed on other organisms, or symbiotic due to the interaction with insects. However, looking at the nature of these species, they actively capture and digest insects for nutrients, exemplified by Venus flytraps, which directly points to them being carnivorous. Common mistake: Confusing the predatory nutritional capture of insects with a parasitic host relationship.

Students might select photosynthesis since it is a primary plant energy process, or photolysis which is a light reaction stage. By tracking the breakdown of glucose molecules into the energy currency of cells, we arrive at respiration as the mechanism that converts chemical energy into ATP. Common mistake: Mixing up photosynthesis, which builds up energy storage molecules, with cellular respiration, which releases ATP.

A student might incorrectly choose that they have mycelium or are multicellular, which are structural features rather than nutritional classifications. Fungi rely on external nutrients and cannot photosynthesize because of the absence of chlorophyll, making them heterotrophic. Common mistake: Attributing nutritional classification to structural traits like being multicellular instead of metabolic capabilities.

A student might pick Amoeba or Paramecium, which are common free-living protozoans found in pond water. Focusing on the pathogenic and disease-causing traits specified, Plasmodium is the correct answer because it causes malaria and acts as a parasitic protozoan. Common mistake: Confusing non-pathogenic aquatic protozoans with disease-causing parasitic species.