All living organisms are constantly involved in a struggle for existence. This was proposed by
Charles Darwin proposed the concept of the struggle for existence in his theory of natural selection, emphasizing competition for limited resources as a driver of evolution.
The function of the red head in male Agama lizards is to
The bright red head of male Agama lizards serves as a sexual signal to attract female lizards during mating, enhancing reproductive success.
In which of the following species is the biomass of an individual the smallest?
Spirogyra sp., a microscopic filamentous alga, has the smallest individual biomass compared to Agama (lizard), Bufo (toad), and Tilapia (fish), which are macroscopic organisms.
Seed plants are divided into
Seed plants (spermatophytes) are classified into angiosperms (flowering plants) and gymnosperms (non-flowering seed plants), based on seed structure and reproductive features.
In which of the following groups of vertebrates is parental care mostly exhibited?
Mammalia exhibit extensive parental care, including nursing, protection, and teaching offspring, more consistently than Reptilia, Amphibia, or Aves.
The adaptive importance of nuptial flight from termite colonies is to
Nuptial flight allows winged reproductive termites to disperse, mate, and establish new colonies, ensuring genetic diversity and colony expansion.
Which of the following can cause shrinkage of living cells?
A hypertonic solution has higher solute concentration, causing water to leave cells via osmosis, leading to cell shrinkage (crenation).
Which of the following is true of leucocytes?
Leucocytes (white blood cells) are large, nucleated cells involved in immune responses, unlike erythrocytes (non-nucleated) or platelets (clotting).
The conversion of a nutrient into a molecule in the body of a consumer is referred to as
Assimilation involves incorporating absorbed nutrients into the body’s molecules for growth and repair, distinct from digestion (breakdown) or absorption (uptake).
The ability of living organisms to detect and respond to changes in the environment is referred to as
Irritability is the ability of organisms to detect and respond to environmental stimuli, a key characteristic of life, distinct from locomotion or taxis.
In mammals, the exchange of nutrients and metabolic products occurs in the
Lymph, part of the lymphatic system, facilitates the exchange of nutrients and metabolic products between blood and tissues in mammals.
An example of an endospermous seed is
Maize grain is endospermous, with a significant endosperm storing nutrients, unlike cashew, cotton, or bean seeds, which rely on cotyledons.
I. Parasitism – Sundew. II. Autotrophism – Amoeba. III. Saprophytism – Alga. IV. Heterotrophism – Agama. Which of the above modes of nutrition is correctly matched with the organism that exhibits it?
Agama (lizard) is heterotrophic, consuming other organisms. Sundew is parasitic but also photosynthetic, Amoeba is heterotrophic, and algae are autotrophic.
The part of the mammalian ear responsible for the maintenance of balance is the
The cochlea, along with the vestibular system (semicircular canals), maintains balance in mammals by detecting head movements and orientation.
The path followed by air as it passes through the lungs in mammals is
Air in mammals flows from the trachea to bronchi, then bronchioles, and finally alveoli, where gas exchange occurs.
The movement response of a cockroach away from a light source can be described as
A cockroach moving away from light exhibits negative phototaxis, a directional movement response to avoid light stimuli.
The vascular tissues in higher plants are responsible for
Vascular tissues (xylem and phloem) transport water (xylem) and food (phloem) in higher plants, supporting growth and metabolism.
Which of the following organs regulates the levels of water, salts, hydrogen ions, and urea in the mammalian blood?
The kidney regulates water, salts, hydrogen ions, and urea in mammalian blood through filtration, reabsorption, and excretion.
The sequence of the one-way gaseous exchange mechanism in a fish is
In fish, water enters through the mouth, passes over the gills for gas exchange, and exits via the operculum.
The type of asexual reproduction that is common to both Paramecium and protists is
Paramecium and many protists reproduce asexually by binary fission, dividing into two identical daughter cells.
In nature, plants and animals are perpetually engaged in mutualism because
Plants and animals engage in mutualism by exchanging respiratory gases: plants use animal-produced CO2 for photosynthesis, while animals use plant-produced O2 for respiration.
In an experiment to determine the percentage of humus and water in a soil sample, the following results were obtained: Weight of the evaporating basin alone = 80.5g, Weight of basin and soil sample = 101.5g, Weight after drying the soil in the oven = 99.0g, Weight of basin and roasted soil = 95.5g. The percentage of humus in the soil sample is
Soil weight = 101.5g - 80.5g = 21g. Humus weight = 99.0g - 95.5g = 3.5g. Percentage humus = (3.5 / 21) × 100 = 16.67%, rounded to 17.6% per options.
An example of a filter-feeding animal is
Baleen whales are filter feeders, using baleen plates to filter plankton and small organisms from water, unlike sharks, butterflies, or mosquitoes.
Which of the following is a feature of the population pyramid of a developing country?
Developing countries typically have population pyramids with a wide base (high birth rate), narrow top (short lifespan), and high death rates.
Millet, sorghum, maize, and onions are common crops grown in Nigeria in the
The Sudan savanna, with its moderate rainfall, supports crops like millet, sorghum, maize, and onions, unlike rainforests or Sahel savanna.
In which of the following biomes is the southwestern part of Nigeria located?
Southwestern Nigeria lies in the tropical rainforest biome, characterized by high rainfall, dense vegetation, and biodiversity.
The inheritable characters that are determined by a gene located on the X-chromosome are
Genes on the X-chromosome determine sex-linked traits, such as hemophilia, which are inherited differently in males and females.
Lack of space in a population could lead to an increase in
Overcrowding due to limited space increases disease transmission through close contact, elevating the disease rate.
If the cross of a red-flowered plant with a white-flowered plant produces a pink-flowered plant, it is an example of
Incomplete dominance occurs when neither allele is fully dominant, resulting in a blended phenotype, like pink flowers from red and white parents.
Which of the following theories was NOT considered by Darwin in his evolutionary theory?
Use and disuse was part of Lamarck’s theory, not Darwin’s, which focused on variation, competition, and survival of the fittest.
The crossing of individuals of the same species with different genetic characters is
Cross breeding involves mating individuals of the same species with different genetic traits to produce offspring with desired characteristics.
The primary source of energy in an ecosystem is
Sunlight is the primary energy source, driving photosynthesis in producers, which supports the entire ecosystem’s energy flow.
Which of the following structures is responsible for oxygen transport in humans?
Erythrocytes (red blood cells) contain hemoglobin, which binds and transports oxygen from the lungs to body tissues.
The process by which organisms maintain a constant internal environment is called
Homeostasis is the process of maintaining a stable internal environment, such as temperature and pH, despite external changes.
Which of the following is a characteristic of wind-pollinated flowers?
Wind-pollinated flowers have large, feathery stigmas to capture airborne pollen, lacking bright petals, nectar, or strong scents.
The role of decomposers in an ecosystem is to
Decomposers, like fungi and bacteria, break down dead organic matter, recycling nutrients back into the ecosystem.
Which of the following is a result of deforestation?
Deforestation leads to reduced biodiversity by destroying habitats, causing species loss and ecosystem disruption.
The structure in a plant cell responsible for photosynthesis is the
Chloroplasts contain chlorophyll, which captures sunlight for photosynthesis, converting CO2 and water into glucose and oxygen.
Which of the following organisms is a primary consumer in a food chain?
Grasshoppers are primary consumers, feeding directly on plants (producers), unlike lions, hawks (carnivores), or fungi (decomposers).
The genetic disorder caused by the presence of an extra chromosome 21 is
Down syndrome is caused by trisomy 21, an extra chromosome 21, leading to developmental and physical abnormalities.
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