UPMSP Intermediate Agricultural Zoology key terms

A fluid-filled body cavity lying between the body wall and the gut, completely lined by mesoderm. Its presence separates pseudocoelomates from true coelomates such as annelids and chordates, and it allows space for organ development and hydrostatic support.

A flexible rod of turgid cells running along the dorsal side of chordates, present at some stage of life. It supports the body axis and is the defining feature of Chordata, later replaced largely by the vertebral column in vertebrates.

A network of seawater-filled canals and tube feet unique to echinoderms. It powers locomotion, food capture and gas exchange, and its radial arrangement is a key character used in identifying starfish, sea urchins and their relatives.

The two-part naming system for organisms, giving a Latinised genus name followed by a specific epithet, both italicised. It was formalised by Linnaeus and gives every species a universally recognised, stable scientific name.

A sheet of closely packed cells covering body surfaces, lining cavities and ducts, or forming glands. Cells rest on a basement membrane, are joined by junctions, and are classified by cell shape and number of layers.

The maintenance of a stable internal environment, such as temperature, pH, blood glucose and water balance, despite external change. It depends on negative feedback loops involving receptors, a control centre and effectors.

The structural and functional unit of the vertebrate kidney. It filters blood at the glomerulus, then reabsorbs useful solutes and water and secretes wastes along the tubule to form urine.

The control of water and dissolved salt concentrations in body fluids so that cells neither swell nor shrink excessively. Freshwater animals excrete dilute urine, marine teleosts drink seawater and excrete salts, and insects use Malpighian tubules.

A mating of an individual showing the dominant phenotype with a homozygous recessive partner. The phenotypes of the offspring reveal whether the tested individual was homozygous dominant or heterozygous, a basic tool in Mendelian analysis.

Transmission of genes located on the sex chromosomes, so that inheritance patterns differ between males and females. Traits such as colour blindness in humans or barred plumage in poultry show characteristic criss-cross transmission.

A heritable change in the DNA sequence of a gene or chromosome. Mutations may be spontaneous or induced, are usually random with respect to need, and provide the raw variation on which selection acts.

The proportion of total phenotypic variation in a population that is due to genetic variation. High heritability for a trait means selection based on individual performance should be effective; low values favour progeny testing.

The superior performance of crossbred offspring over the average of their parents for traits such as growth, yield or fertility. It is greatest between genetically diverse lines and is exploited in hybrid maize and crossbred cattle.

The stage of an insect between two successive moults. Larval instars are numbered first, second and so on; the number is fairly constant for a species and helps in age identification and timing of control measures.

The shedding of the old cuticle during growth in insects and other arthropods. A new soft cuticle is secreted beneath, the old one splits, and the insect expands before the new cuticle hardens and darkens.

Describing insects with complete metamorphosis through egg, larva, pupa and adult. The larva differs markedly from the adult and the pupal stage allows major reorganisation, as in beetles, moths, flies and bees.

Chewing mouthparts built around a pair of hardened jaws, or mandibles, with maxillae, labium and labrum. Found in grasshoppers, beetles and cockroaches, they are adapted for biting and grinding solid food.

The pest population density at which control measures should be applied to prevent the pest from reaching the economic injury level. Using thresholds avoids unnecessary spraying and preserves natural enemies.

A decision-based combination of cultural, mechanical, biological and chemical tactics that keeps pest populations below damaging levels. Pesticides are used only when monitoring justifies them, choosing selective products and following label and safety rules.

The inherited ability of a crop variety to limit the damage or reproduction of a pest. Resistance may act through antibiosis, antixenosis or tolerance, and breeding resistant varieties is a cornerstone of sustainable pest management.

The management of honey bee colonies for honey, beeswax and pollination services. It covers hive types, colony handling, queen rearing, swarming control, disease management and safe harvesting of honey.

The suppression of a pest by its natural enemies, including predators, parasitoids and pathogens. Classical, augmentative and conservation approaches are used, and success depends on correct identification and avoidance of broad-spectrum insecticides.

The lac insect, a scale insect farmed on host trees such as palash and ber for the resinous secretion lac. Females produce the commercial lac, and sticklac is harvested, crushed and washed to give seedlac and shellac.

Meloidogyne species that invade roots and cause galls, stunting and reduced yield in many vegetables and field crops. Second-stage juveniles infect roots, and management uses resistant varieties, rotation, soil solarisation and nematicides.

A chemical used to kill rodent pests, usually formulated as bait. Products differ in acute versus chronic action; anticoagulants such as bromadiolone need repeated feeding, and bait must be placed to avoid non-target exposure.

A pesticide used against slugs and snails, commonly as metaldehyde or methiocarb bait. Applications are placed near susceptible crops, and safe use requires consideration of pets, birds and contamination of water bodies.

The dose of a toxicant expected to kill 50 percent of a test animal population under stated conditions. Expressed usually in milligrams per kilogram body weight, it measures acute toxicity; a lower value means a more toxic product.

A liquid pesticide formulation in which the active ingredient is dissolved in organic solvent with emulsifiers. On dilution with water it forms an emulsion; the formulation is easy to measure but the solvent can damage some crops.

The minimum time in days between the last pesticide application and harvesting the crop. It protects consumers by allowing residues to decline below permitted limits and is specified on the product label.

The first milk secreted after calving, rich in antibodies, protein and vitamins. Newborn calves and other young must receive it within the first hours of life to gain passive immunity against infection.

A chicken bred and reared specifically for fast growth and meat production, usually slaughtered at six to eight weeks. Broiler management emphasises balanced feed, ventilation, litter quality and prevention of heat stress.

A polyculture system stocking several carp species with different feeding habits in one pond, so that surface, column and bottom food resources are used fully. Common combinations include catla, rohu and mrigal.

An inflammation of the mammary gland, usually bacterial, common in dairy cows. It lowers milk yield and quality; control relies on milking hygiene, post-milking teat dip, dry-cow therapy and clean bedding.

A series of organisms through which energy and nutrients pass as one eats another, starting with producers and passing to herbivores and then carnivores. Arrows show energy flow, and chains interlink into food webs.

The increase in concentration of a persistent substance, such as DDT or methylmercury, in organisms at successive trophic levels. Because top predators accumulate the highest residues, the effect damages wildlife even at low environmental doses.

A region with exceptionally high numbers of endemic species that has lost much of its original habitat. Conservation priority is high there; in India the Western Ghats and the Himalaya are recognised hotspots.

Nutrient enrichment of a water body, especially by nitrogen and phosphorus runoff, causing algal blooms, oxygen depletion and fish kills. It threatens aquatic fauna and is controlled by reducing fertiliser and sewage discharge.

A protected area managed mainly for ecosystem protection and recreation, where grazing, cultivation and resource extraction are prohibited. A core zone is kept free of human interference; examples include Kaziranga and Gir.