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Past Questions
The study of the mechanism by which genes bring about their phenotypic effects is called as-
A)
Epigenetics
B)
Exogenetics
C)
Endogenetics
D)
cytogenetics
The question asks for the study of the mechanism by which genes bring about their phenotypic effects. While the classical term for the process of a gene producing a phenotype is 'gene expression', among the given options, 'Epigenetics' is the most relevant scientific field. Epigenetics studies the heritable changes in gene expression (phenotypic effects) that do not involve alterations to the underlying DNA sequence (such as DNA methylation and histone modification).
Analysis of other options:
- b. Exogenetics: This is not a standard term in genetics referring to the mechanism of phenotypic expression.
- c. Endogenetics: This is not a standard term used to describe the general mechanism of gene-to-phenotype expression.
- d. Cytogenetics: This is the study of inheritance in relation to the structure and function of chromosomes (e.g., karyotyping), rather than the molecular mechanism of how a specific gene creates a phenotypic effect.
Note: In some contexts, the general study of how genes produce phenotypes is called 'Genetics' or 'Molecular Biology', but within these specific options, Epigenetics is the only recognized field that focuses on the regulatory mechanisms controlling phenotypic outcomes.
The primary cause of fruit softening during ripening is the breakdown of:
A)
Cellulose
B)
Pectin
C)
Starch
D)
Protein
Fruit softening is a key physiological change during the ripening process. The structural integrity of the fruit cell wall is maintained by the middle lamella, which acts as a 'glue' holding adjacent cells together. This middle lamella is primarily composed of pectin (specifically calcium pectates). During ripening, enzymes such as pectinmethylesterase (PME), polygalacturonase (PG), and pectin lyase are activated. These enzymes break down the pectin polysaccharides into smaller, soluble units, leading to the dissolution of the middle lamella and the subsequent softening of the fruit tissue.
Why other options are incorrect:
- a. Cellulose: While cellulose provides the primary structural framework of the cell wall, it is much more resistant to degradation during ripening compared to pectin. Its breakdown is minimal during normal ripening.
- c. Starch: Starch breakdown (hydrolysis into sugars) occurs during ripening to increase sweetness, but this affects the taste and energy content, not the structural firmness of the fruit.
- d. Protein: While some proteins are degraded during ripening, they are not the primary structural components responsible for the rigidity or softening of the fruit tissue.
Which among the following is a vector of little leaf of Brinjal?
A)
Aphid
B)
White fly
C)
Leafhopper
D)
Mite
Little leaf of brinjal (eggplant) is caused by a phytoplasma (formerly known as Mycoplasma). Phytoplasmas are specialized bacteria that lack a cell wall and are restricted to the phloem of the host plant. Because they cannot penetrate the plant epidermis on their own, they require a biological vector for transmission. The primary vector for the little leaf of brinjal is the leafhopper (specifically species like *Hishimonohyla* spp. or other Cicadellidae).
Analysis of other options:
- a. Aphids: While they transmit many viral diseases, they are not the primary vector for brinjal little leaf.
- b. White fly: These are primary vectors for Geminiviruses (e.g., Yellow vein mosaic of okra/brinjal), not phytoplasmas.
- d. Mites: Mites typically transmit Tospoviruses or cause physiological damage, but not the phytoplasma causing little leaf.
Citrus canker is caused by-
A)
Xanthomonus campestrispv citri
B)
Albugo candida
C)
Erwinia amylovora
D)
Plasmoparaviticola
Step-by-step reasoning:
1. **Analysis of the Disease**: Citrus canker is a destructive bacterial disease affecting citrus plants worldwide, characterized by necrotic, corky lesions on leaves, stems, and fruits.
2. **Identifying the Pathogen**: The disease is caused by the bacterium *Xanthomonas axonopodis* pv. *citri* (formerly and often referred to in textbooks as *Xanthomonas campestris* pv. *citri*). This matches option (a).
3. **Evaluating Other Options**:
- **b. Albugo candida**: This is an oomycete that causes 'White Rust' in crucifers (e.g., mustard).
- **c. Erwinia amylovora**: This bacterium causes 'Fire Blight' in pome fruits like apples and pears.
- **d. Plasmopara viticola**: This is an oomycete that causes 'Downy Mildew' of grapes.
4. **Conclusion**: Based on the pathology of citrus crops, the only correct causative agent listed is the Xanthomonas species.
Which of the following apparatus is commonly used to measure the rate of transpiration?
A)
Porometer
B)
Altimeter
C)
Potometer
D)
Luxmeter
Step-by-step reasoning:
1. Transpiration is the process of water movement through a plant and its evaporation from aerial parts, such as leaves, stems, and flowers.
2. A Potometer is a device used to measure the rate of water uptake by a shoot, which is almost equal to the rate of transpiration. It typically consists of a capillary tube and a scale to measure the movement of an air bubble as the plant absorbs water.
3. Analysis of other options:
- a. Porometer: Used to measure stomatal conductance (the rate at which gases/water vapor exit through stomata), not the overall rate of transpiration of the plant.
- b. Altimeter: An instrument used to measure altitude (height above sea level).
- d. Luxmeter: An instrument used to measure the intensity of light (illuminance).
Therefore, the potometer is the correct apparatus for measuring the rate of transpiration.
Wilting syndrome known as “kresek” occurs in-
A)
Bacterial blight of rice
B)
Blast of rice
C)
Bacterial wilt of cotton
D)
Brown spot of rice
The term 'Kresek' is a specific Indonesian term used to describe the systemic phase of Bacterial Blight of Rice, caused by the bacterium Xanthomonas oryzae pv. oryzae. In this syndrome, the bacteria enter the plant through the hydathodes of young seedlings, leading to the wilting, yellowing, and drying of the leaves, which often results in the death of the seedling.
Why other options are incorrect:
- b. Blast of rice: Caused by the fungus Magnaporthe oryzae; it typically manifests as spindle-shaped lesions on leaves or neck rot, not as a systemic wilting syndrome called kresek.
- c. Bacterial wilt of cotton: Caused by Ralstonia solanacearum; while it causes wilting, it is not referred to as 'kresek'.
- d. Brown spot of rice: Caused by the fungus Bipolaris oryzae; it manifests as small, oval, brown spots on the leaves, not as a wilting syndrome.
The first stable compound formed during photosynthesis in C3 plant is-
A)
PEP
B)
3PGA
C)
Oxaloacetic acid
D)
RuBP
In C3 plants, the first step of the Calvin cycle (C3 cycle) involves the fixation of carbon dioxide (CO2) by the enzyme Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO). The CO2 molecule combines with a 5-carbon sugar called Ribulose-1,5-bisphosphate (RuBP) to form an unstable 6-carbon intermediate. This unstable intermediate immediately splits into two molecules of 3-phosphoglyceric acid (3-PGA), which is a 3-carbon compound. Because the first stable product is a 3-carbon molecule, these plants are called C3 plants.
Analysis of other options:
- a. PEP (Phosphoenolpyruvate): This is the primary CO2 acceptor in C4 plants, not C3 plants.
- c. Oxaloacetic acid (OAA): This is the first stable 4-carbon compound formed in C4 plants.
- d. RuBP (Ribulose-1,5-bisphosphate): This is the CO2 acceptor molecule, not the product formed after fixation.
Aman made Allopolyploid crop is-
A)
bread wheat
B)
Maize
C)
Triticale
D)
Sugarcane
Step-by-step reasoning: 1. Definition: Allopolyploidy occurs when an organism has more than two sets of chromosomes, derived from two or more different species. This is typically achieved through hybridization followed by chromosome doubling. 2. Analysis of Triticale: Triticale is a classic example of a man-made allopolyploid. It was created by crossing Wheat (Triticum) and Rye (Secale). Because the two species are different, the resulting hybrid was initially sterile; however, through chromosome doubling (often using colchicine), a fertile allopolyploid was created. 3. Analysis of other options: (a) Bread wheat is an allohexaploid, but it evolved naturally over time through multiple hybridization events, not 'man-made' in the same sense as Triticale. (b) Maize is a diploid (though it has a complex genome with some duplication). (d) Sugarcane is a natural polyploid complex, though humans have bred it extensively. 4. Conclusion: Triticale is the definitive example of a synthetic (man-made) allopolyploid crop.
Increased vigour of hybrids over parents results from-
A)
Selection
B)
Heterosis
C)
Hybridization
D)
Mutation
Step-by-step reasoning: 1. The question asks for the term describing the increased vigour, growth, or productivity of a hybrid (F1 generation) compared to its parents. 2. Heterosis, also known as 'hybrid vigour', is the biological phenomenon where the progeny of diverse parents exhibits superior traits (such as yield, size, or resilience) relative to the average of the parents. 3. Analysis of other options: (a) Selection is the process of choosing specific plants for breeding based on desired traits, not the result of hybrid vigour itself. (c) Hybridization is the process of crossing two genetically different individuals; while it is the method used to achieve heterosis, the 'increased vigour' itself is called heterosis. (d) Mutation is a spontaneous or induced change in the DNA sequence, which may create new traits but does not specifically describe the superiority of hybrids over parents. Therefore, Heterosis is the correct technical term.
Self-Pollination increases which of the following?
A)
Heterozygosity
B)
Homozygosity
C)
Heterogenity
D)
Homogeneity
Self-pollination (autogamy) occurs when pollen from the anther of a flower is transferred to the stigma of the same flower or another flower on the same plant. In genetics, repeated self-pollination leads to a reduction in heterozygosity and an increase in homozygosity. Specifically, in each generation of selfing, the proportion of heterozygous loci is reduced by 50%, while the proportion of homozygous loci (both dominant and recessive) increases. This process is fundamental in plant breeding for developing 'pure lines' or inbred lines.
Analysis of other options:
- a. Heterozygosity: This is decreased by self-pollination and increased by cross-pollination.
- c. Heterogenity: This refers to diversity within a population; self-pollination tends to make individuals more genetically similar (reducing heterogeneity).
- d. Homogeneity: While a population of selfed plants may appear homogeneous (uniform), the biological process occurring at the genetic level is specifically the increase in 'homozygosity' (identical alleles at a locus). In technical plant breeding terms, homozygosity is the precise genetic result of selfing.
Litchi is native to-
A)
North China
B)
India
C)
North America
D)
South China
Litchi (Litchi chinensis) is a tropical fruit tree. Botanically and historically, it is native to the subtropical regions of South China, specifically the provinces of Guangdong and Fujian. From South China, it spread to other parts of Asia, including India and Southeast Asia.
Analysis of options:
- a. North China: Incorrect. The climate in North China is generally too cold for the cultivation of litchi, which requires a humid subtropical environment.
- b. India: Incorrect. While India (specifically Bihar and West Bengal) is a major producer of litchi today, it is not the native origin of the species.
- c. North America: Incorrect. Litchi is not native to the Americas; it was introduced there much later.
- d. South China: Correct. This is the center of origin for Litchi chinensis.
Antheraea assama produced which type of silk?
A)
Erisilk
B)
Muga silk
C)
Tasar
D)
Mulberry
Step-by-step reasoning:
1. Identification of the species: Antheraea assamensis (often referred to as Antheraea assama in some contexts) is the silkworm species responsible for producing Tasar silk, specifically the Tropical Tasar variety.
2. Analysis of options:
- Option (a) Erisilk: Produced by Samia ricini.
- Option (b) Muga silk: Produced by Antheraea assamensis (specifically the Muga variety), but in general biological and sericultural classification, the genus Antheraea is primarily associated with Tasar (wild silk). However, it is important to note that while Muga is a distinct gold-colored silk from Assam, the broader category of 'Tasar' includes various Antheraea species. In most standard competitive exams, Antheraea species (excluding the specific Muga silkworm) are categorized under Tasar.
- Option (c) Tasar: This is the correct general category for silk produced by the Antheraea genus (such as A. paphia and A. assamensis/assama).
- Option (d) Mulberry: Produced by Bombyx mori.
3. Conclusion: Antheraea assama/assamensis is the primary producer of Tasar silk (specifically Tropical Tasar).
Offspring from cross between two individuals differ in at least one character or trait is-
A)
Polyploid
B)
Hybrids
C)
Mutants
D)
Varieties
In plant breeding and genetics, a 'Hybrid' is defined as the offspring resulting from the cross between two genetically different parents (individuals). Because the parents differ in their genetic makeup, the resulting offspring will differ from the parents and potentially from each other in at least one character or trait. This process is often utilized to achieve 'hybrid vigor' or heterosis.
Why other options are incorrect:
- a. Polyploid: This refers to an organism with more than two complete sets of chromosomes (e.g., triploid, tetraploid). While polyploidy can result from hybridization, it describes the chromosome number, not the act of crossing two different individuals to produce differing traits.
- c. Mutants: A mutant is an organism that has undergone a spontaneous or induced change in its DNA sequence. Mutation is a process of genetic alteration within a lineage, not necessarily the result of a cross between two individuals.
- d. Varieties: A variety is a taxonomic rank or a group of plants within a species that share specific characteristics. While hybrids can be developed into varieties, the term 'variety' describes a categorized group rather than the specific offspring of a cross.
Across between open pollinated variety and pure line selection is-
A)
Top cross
B)
Double cross
C)
Synthetic cross
D)
Selfcross
In plant breeding, a 'Top Cross' is a specific type of cross used to test the combining ability of a breeding line. It involves crossing a promising line (such as a pure line selection or an inbred line) with a genetically diverse, broad-based population, typically an Open Pollinated Variety (OPV) or a commercial cultivar. This allows the breeder to evaluate the general combining ability (GCA) of the pure line.
Why other options are incorrect:
- b. Double cross: This involves crossing two single-cross hybrids (F1 x F1) to produce a double-cross hybrid, typically used in maize breeding.
- c. Synthetic cross: This involves crossing a set of inbred lines or clones that have been tested for general combining ability to create a genetically diverse but uniform population.
- d. Selfcross: This is the process of self-pollination (crossing a plant with itself) to increase homozygosity, not a cross between two different types of populations like an OPV and a pure line.
Aflatoxin is produced by-
A)
Penicillium spp
B)
Trichoderma spp
C)
Aspergillus niger
D)
Aspergillus flavus
Aflatoxins are potent mycotoxins (carcinogenic and hepatotoxic substances) produced primarily by certain molds of the genus Aspergillus. The most prominent species responsible for the production of aflatoxins, particularly in stored grains, corn, and peanuts, is Aspergillus flavus. While Aspergillus parasiticus also produces them, Aspergillus flavus is the primary species listed in the options.
Analysis of other options:
- Penicillium spp: These produce different types of mycotoxins, such as Patulin or Ochratoxin A, but not Aflatoxin.
- Trichoderma spp: These are generally used as biocontrol agents (e.g., Trichoderma viride) to fight other fungi and are not known for producing aflatoxins.
- Aspergillus niger: While it belongs to the same genus, A. niger is primarily used in industrial citric acid production and is not a producer of aflatoxins.
Site of protein synthesis in a cell is-
A)
Ribosomes
B)
Endoplasmic reticulum
C)
Chloroplasts
D)
Mitochondria
Step-by-step reasoning:
1. Protein synthesis is the process by which cells build proteins, involving two main stages: transcription (DNA to mRNA) and translation (mRNA to protein).
2. Translation occurs at the ribosomes, which are complex molecular machines made of RNA and proteins. Ribosomes read the genetic code carried by messenger RNA (mRNA) and assemble amino acids into polypeptide chains.
3. Evaluating the options:
- (a) Ribosomes: The primary and universal site of protein synthesis in all living cells (prokaryotic and eukaryotic).
- (b) Endoplasmic reticulum: While the 'Rough ER' is studded with ribosomes and is involved in the folding and transport of proteins, the actual synthesis is performed by the ribosomes attached to it, not the ER membrane itself.
- (c) Chloroplasts: These are sites of photosynthesis. While they contain their own internal ribosomes to make a few specific proteins, they are not the general site of protein synthesis for the cell.
- (d) Mitochondria: These are the 'powerhouses' of the cell (ATP production). Like chloroplasts, they have their own ribosomes for internal use, but they are not the primary site of cellular protein synthesis.
Therefore, the most accurate and general answer is Ribosomes.
The type of damage caused by insect vectors of plant diseases primarily includes:
A)
Chewing and skeletonizing leaves
B)
Sap-sucking and virus transmission
C)
Leafrolling and gall formation
D)
Mining within plant tissues
Step-by-step reasoning: 1. Definition of a Vector: In entomology and plant pathology, a vector is an organism (typically an insect) that transmits a pathogen (virus, bacteria, or phytoplasma) from one plant to another. 2. Mechanism of Transmission: To transmit a systemic pathogen like a virus, the insect must have access to the plant's vascular system (phloem or xylem). This requires piercing-sucking mouthparts. 3. Analysis of Options: (a) Chewing and skeletonizing are caused by insects with mandibulate mouthparts (e.g., grasshoppers, caterpillars), which generally do not act as vectors for systemic viruses. (b) Sap-sucking insects (e.g., aphids, whiteflies, leafhoppers) use stylets to feed on phloem sap, which allows them to acquire and inoculate viruses into the host plant. This is the primary characteristic of disease vectors. (c) Leafrolling and gall formation are specific types of morphological damage, not the primary mechanism of disease vectoring. (d) Mining is caused by larvae feeding between epidermal layers, which is a form of direct tissue damage rather than the primary mode of vectoring systemic diseases. Therefore, option (b) is the most accurate description of the damage and function associated with insect vectors.
Nomenclature of fungi is governed by-
A)
ICBN
B)
ICZN
C)
ICTV
D)
ICFN
The nomenclature of fungi is governed by the International Code of Botanical Nomenclature (ICBN), which has since been updated and renamed as the International Code of Nomenclature for algae, fungi, and plants (ICN).
Here is the breakdown of the options:
1. ICBN (International Code of Botanical Nomenclature): Historically, fungi were classified under the plant kingdom. Therefore, the rules for naming fungi are governed by the botanical code. Even though fungi are now in their own kingdom, they still follow the ICN/ICBN guidelines.
2. ICZN (International Code of Zoological Nomenclature): This governs the naming of animals.
3. ICTV (International Committee on Taxonomy of Viruses): This governs the naming and classification of viruses.
4. ICFN: This is not a standard recognized international nomenclature code for biological organisms.
Koch’s postulates are used to-
A)
Identify beneficial microorganisms
B)
Confirm the causative agent of a disease
C)
Develop antibiotic resistance in bacteria
D)
Sterilize infected tissue samples
Koch's postulates are a set of four criteria established by Robert Koch in the late 19th century to establish a causative relationship between a microbe and a disease. The steps are: 1) The microorganism must be found in abundance in all organisms suffering from the disease but should not be found in healthy organisms. 2) The microorganism must be isolated from a diseased organism and grown in pure culture. 3) The cultured microorganism should cause disease when introduced into a healthy organism. 4) The microorganism must be re-isolated from the inoculated, diseased experimental host and identified as being identical to the original specific causative agent.
Why other options are incorrect:
- Option (a): Koch's postulates are specifically designed to identify pathogens (harmful microbes), not beneficial ones.
- Option (c): Developing antibiotic resistance is a biological process of evolution/mutation, not a diagnostic procedure.
- Option (d): Sterilization is a laboratory technique to remove contaminants, whereas Koch's postulates are a scientific methodology for disease attribution.
Little leaf of brinjal is caused by-
A)
Fungus
B)
Bacteria
C)
Mycoplasma like organism-phytoplasma
D)
Virus
Little leaf of brinjal (eggplant) is a systemic disease characterized by the reduction in the size of leaves, resulting in a 'bushy' appearance of the plant. This disease is caused by Phytoplasmas, which are specialized Mycoplasma-like organisms (MLOs). These organisms are wall-less prokaryotes that inhabit the phloem of the host plant and are typically transmitted by insect vectors, most commonly leafhoppers.
Why other options are incorrect:
- a. Fungus: Fungal pathogens typically cause wilts, blights, or root rots (e.g., Fusarium wilt in brinjal), not the specific 'little leaf' hormonal imbalance.
- b. Bacteria: Bacterial infections usually cause spots, galls, or wilts (e.g., Bacterial wilt caused by Ralstonia), but not the phytoplasma-induced stunting seen in little leaf.
- d. Virus: While viruses can cause leaf curling or mosaics, the specific etiology of 'Little Leaf of Brinjal' is well-documented as being caused by phytoplasmas, which are distinct from viruses in their cellular structure (they are prokaryotes, whereas viruses are non-cellular genetic material).
Crystallization of virus was first done by-
A)
W.M Stanley
B)
M.W. Beijerinck
C)
D.L.Ivanowski
D)
Adulf Mayer
The correct answer is W.M. Stanley. In 1935, Wendell Meredith Stanley succeeded in crystallizing the Tobacco Mosaic Virus (TMV), demonstrating that viruses consist of protein and nucleic acid and can be treated as chemical substances. This discovery was pivotal in the field of virology and earned him the Nobel Prize in Chemistry in 1946.
Why other options are incorrect:
- M.W. Beijerinck: He is credited with discovering that the cause of tobacco mosaic disease was a 'contagium vivum fluidum' (contagious living fluid) and coined the term 'virus'.
- D.L. Ivanowski: He discovered that the agent causing tobacco mosaic disease could pass through filters that trapped bacteria, proving it was smaller than bacteria.
- Adolf Mayer: He was the first to demonstrate that tobacco mosaic disease was infectious, though he believed it was caused by a very small bacterium.
A plant in which gene has been transferred through genetic engineering is called-
A)
Hybrid
B)
Pure line selection
C)
Back cross line
D)
Transgenic plant
Step-by-step reasoning:
1. Analysis of the question: The question asks for the term used to describe a plant that has received a foreign gene via genetic engineering (recombinant DNA technology).
2. Evaluating Option (d): A 'Transgenic plant' (also known as a Genetically Modified Organism or GMO) is specifically defined as an organism that contains genetic material into which DNA from an unrelated organism has been artificially introduced using biotechnology tools.
3. Evaluating Option (a): A 'Hybrid' is the offspring of two plants of different varieties, species, or breeds produced through sexual reproduction (cross-pollination), not necessarily through genetic engineering.
4. Evaluating Option (b): 'Pure line selection' is a traditional breeding method where plants are self-pollinated over several generations to achieve homozygosity; it does not involve transferring genes from other species.
5. Evaluating Option (c): 'Back cross line' refers to a breeding technique where a hybrid is crossed back with one of its parents to recover a specific trait; this is a conventional breeding method, not genetic engineering.
Conclusion: Only 'Transgenic plant' refers to the process of gene transfer via genetic engineering.
Which insect order includes the majority of vectors for plant viral diseases?
A)
Coleoptera
B)
Hemiptera
C)
Orthoptera
D)
Hymenoptera
Step-by-step reasoning: 1. Plant viral diseases are typically transmitted by insects that feed on plant sap (phloem or xylem), as viruses are systemic and reside within the vascular system. 2. The order Hemiptera (true bugs) includes aphids, whiteflies, leafhoppers, planthoppers, and mealybugs. These insects possess piercing-sucking mouthparts (stylets) specifically adapted for extracting sap. 3. Because of their feeding mechanism, Hemipterans are the primary vectors for the vast majority of plant viruses (e.g., Potyviruses transmitted by aphids, Geminiviruses transmitted by whiteflies). 4. Evaluating other options: (a) Coleoptera (beetles) can transmit some viruses but are far fewer in number compared to Hemipterans. (c) Orthoptera (grasshoppers) are chewing insects and are not significant vectors for plant viruses. (d) Hymenoptera (bees, wasps) are primarily pollinators or parasitoids and are not major vectors for plant viral diseases.
Ufra disease of rice is caused by the nematode:
A)
Ditylenchus angustus
B)
Trichinella spiralis
C)
Meloidogyne incognita
D)
Helicotylenchus multicinctus
Ufra disease of rice is a serious systemic disease caused by the migratory endoparasitic nematode Ditylenchus angustus. The nematode enters the roots and moves upward into the xylem vessels, causing the characteristic symptoms of 'Ufra' (which means 'stunted' or 'dwarf' in local languages), including stunted growth, yellowing of leaves, and root decay.
Analysis of other options:
- b. Trichinella spiralis: This is a parasitic nematode that infects animals (including humans), causing trichinosis; it is not a plant pathogen.
- c. Meloidogyne incognita: This is the root-knot nematode, which causes galls on the roots of a wide variety of crops, but it does not cause Ufra disease.
- d. Helicotylenchus multicinctus: This is a spiral nematode that can cause root damage in various crops, but it is not the causal agent of Ufra disease in rice.
The major predator of lac insect.
A)
Mantisreligiosa
B)
Eublemmaamabilis
C)
Coccinellaseptempunctata
D)
Chrysoperlacarnea
The lac insect (Kerria lacca) is subject to various pests and predators. Among the options provided, Eublemma amabilis (a species of moth/pyralid) is recognized as a significant predator/pest of lac insects, specifically attacking the lac cells.
Analysis of other options:
- Mantis religiosa (Praying Mantis) is a generalist predator that feeds on various insects but is not the 'major' specific predator of lac insects.
- Coccinella septempunctata (Seven-spot ladybird) is a major predator of aphids and scale insects, but not the primary predator associated with lac culture.
- Chrysoperla carnea (Green lacewing) is a generalist predator of soft-bodied insects (like aphids and mealybugs) but is not the primary predator of lac insects.
In the context of lac culture (laculture), Eublemma amabilis is a well-documented pest/predator that causes significant damage to the lac crop.