The ability of organisms to maintain a constant internal environment is known as
Homeostasis is the process by which organisms regulate their internal environment to maintain stable conditions, such as temperature and pH, despite external changes. Diuresis refers to increased urine production, endosmosis is water movement into cells, and plasmolysis is cell shrinkage due to water loss.
Which of the following is a characteristic feature of a dicotyledonous leaf?
Dicotyledonous leaves typically exhibit reticulate venation, where veins form a net-like pattern branching from the midrib. Parallel venation is characteristic of monocots, while broad base and tapering apex are general leaf shapes not specific to dicots.
Which of the following would improve the accuracy of a biological drawing?
A clear title identifies the subject, and magnification indicates scale, ensuring the drawing is precise and reproducible. Colors may aid identification but not accuracy, unlabeled drawings lack clarity, and exaggeration distorts proportions.
Which group of organisms is unicellular and prokaryotic?
Bacteria are unicellular prokaryotes lacking a nucleus and membrane-bound organelles. Fungi and algae can be multicellular/eukaryotic, protozoa are unicellular eukaryotes.
The causative agent of cholera belongs to which kingdom?
Cholera is caused by Vibrio cholerae, a bacterium in the kingdom Monera (prokaryotes). Plantae includes plants, Animalia animals, Fungi fungi.
Which sequence represents increasing levels of organization in living organisms?
The hierarchy of organization progresses from cells (basic unit) to tissues (groups of cells), organs (tissues forming structures), and systems (organs working together).
Snails belong to the phylum
Snails are mollusks in phylum Mollusca, characterized by soft bodies often with shells. Arthropoda includes insects/crustaceans, Annelida segmented worms, Chordata vertebrates/invertebrates with notochords.
In a plant cell, the site of the Calvin cycle during photosynthesis is the
The Calvin cycle (light-independent reactions) occurs in the stroma, where CO2 is fixed into glucose using ATP/NADPH from light reactions in thylakoids. Mitochondria handle respiration, nucleus DNA.
During photosynthesis, oxygen is released from the splitting of
Photolysis of water (2H2O → 4H+ + 4e- + O2) in photosystem II releases oxygen as a byproduct. CO2 is fixed later, glucose produced in Calvin cycle, chlorophyll absorbs light.
An example of a process that involves osmosis is the
Osmosis is passive water movement across semi-permeable membranes from low to high solute concentration; reabsorption in kidney nephrons occurs via osmosis in proximal tubules. Food movement is active transport, translocation via phloem.
Growth in animals differs from that in plants because growth in
Plant growth is indefinite (lifelong at meristems), while animal growth is determinate (stops after maturity). Intercalary/apical refer to plant growth locations, 'from within' not specific.
The axial skeleton in humans includes the
Axial skeleton forms the body's central axis: skull, vertebral column, ribs, sternum. Appendicular includes limbs and girdles.
In a road accident, damage to the vertebral column is most likely to affect the
Vertebral column protects spinal cord, transmitting nerve signals for motor functions; damage causes paralysis, impairing walking. Balance via inner ear, digestion autonomic, hearing auditory nerve.
The tricuspid valve is located between the
Tricuspid valve prevents backflow from right ventricle to right atrium during contraction. Mitral between left sides, semilunar at aorta/pulmonary.
In the human respiratory system, the pathway of air is
Air enters nostrils, passes pharynx (shared with food), larynx (voice), trachea (windpipe), bronchi (branches), bronchioles, to alveoli for gas exchange.
The lungs are protected by the
Rib cage encases lungs, providing bony protection against injury. Diaphragm aids breathing, heart adjacent, sternum part of rib cage.
Which of the following hormones is wrongly paired with its secretory organ?
Oxytocin is produced in hypothalamus and released by posterior pituitary, not ovary. Insulin by pancreas beta cells, oestrogen by ovaries.
The eye defect caused by uneven curvature of the cornea or lens is
Astigmatism causes blurred vision due to irregular corneal/lens curvature, distorting light focus. Myopia near-sightedness, presbyopia age-related, hypermetropia far-sightedness.
The androecium in a flowering plant is a collection of
Androecium is the male whorl comprising stamens (filament + anther). Ovules in gynoecium, sperms in pollen, filaments part of stamen.
Placentation in fruits is referred to as the
Placentation describes ovule attachment/arrangement on placenta in ovary (e.g., marginal, axile). Option A vague, B syncarpous, D axile type.
Which of the following processes does not occur during photosynthesis?
Photosynthesis absorbs CO2, splits water (photolysis), evolves O2, absorbs sunlight. CO2 evolution occurs in respiration.
Stunted growth and small yellow leaves in plants are symptoms of the deficiency of
Nitrogen deficiency causes chlorosis (yellowing) in older leaves and stunted growth, as N is vital for chlorophyll/proteins. Sulphur pale leaves, iron young leaves, magnesium interveinal chlorosis.
The structure that its action could result in choking when talking and eating at the same time is
Epiglottis folds over larynx during swallowing to prevent food entering trachea; simultaneous talking disrupts, causing choking. Oesophagus transports food, liver/stomach digest.
The food substance that would produce the highest amount of energy is
Fats yield ~9 kcal/g, highest energy (used for storage). Glucose/carbs 4 kcal/g, proteins/amino acids 4 kcal/g but for growth.
Organisms that feed on dead decaying tissues of other organisms are known as
Saprophytes (e.g., fungi, bacteria) absorb nutrients from dead/decaying matter. Parasites from living hosts, autotrophs self-feed, heterotrophs general consumers.
The type of nutrition in which organisms take in solid organic materials into their body is
Holozoic nutrition involves ingesting solid food, digesting internally (e.g., animals). Symbiotic mutual benefit, saprophytic external digestion of dead, parasitic from host.
The mouthparts of a grasshopper are adapted for
Grasshopper mouthparts (mandibles, maxillae) are biting-chewing type for solid plant material. Grinding partial, sucking for fluids, absorption post-digestion.
A group of organisms belonging to different species that coexist in the same habitat and interact is referred to as
Community comprises interacting populations of different species in a habitat. Population same species, biosphere global life, niche role of species.
Which of the following factors is the main problem facing xerophytes?
Xerophytes (desert plants) face water scarcity, adapting with thick cuticles, reduced leaves. Excess water not issue, sunlight/roots secondary.
Fishes survive in water mainly because they possess
Gills extract dissolved oxygen from water via countercurrent exchange. Streamlined reduces drag, scales protect, fins aid locomotion/balance.
Which of the following instruments is not used in measuring abiotic factors in a habitat?
Microscope magnifies biotic specimens, not abiotic (non-living) factors like temperature (thermometer), humidity (hygrometer), wind (vane).
Which of the following is capillary soil?
Silt and clay have small particles, high capillarity (water rises via adhesion). Sand large particles, low capillarity; loam balanced.
The capturing and digestion of insects by a pitcher plant is a special form of nutrition that is
Pitcher plants are partially heterotrophic, supplementing autotrophic nutrition by digesting insects for nitrogen in poor soils. Chemosynthesis bacteria, saprophytic dead matter.
Which of the following organisms would be the producer in a food chain?
Producers (autotrophs) like maize make food via photosynthesis. Goat/man consumers, bacterium decomposer.
The rate of decomposition of dead organisms is faster in the tropical rain forest than in other biomes because
High moisture and warmth accelerate microbial decomposition, recycling nutrients quickly in rainforests. Cool temps slow, daylight/plants indirect.
In a symbiotic relationship between a bird and a tree, the bird benefits by eating fruits while dispersing seeds, which is an example of
Mutualism benefits both: bird gets food, tree seed dispersal. Commensalism one benefits, parasitism harms host, predation kills prey.
In a typical food chain, the organism with the highest energy content is the
Producers capture maximum solar energy (~100%), with ~10% transfer per trophic level; consumers/decomposers receive less.
Which of the following activities is against the conservation of natural resources?
Deforestation destroys habitats/resources. Afforestation plants trees, reserves protect wildlife, contouring prevents erosion.
The best practice for conserving forests is
Selective logging removes only mature trees, allowing regeneration. Burning/overgrazing/poaching degrade forests.
To promote conservation, governments should
Anti-poaching laws deter illegal hunting, protecting biodiversity. Others exacerbate depletion.
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