Top-Rated Bioherbicide and Bioinsecticide MCQs Class 12 with Detailed Answers

Top-Rated Bioherbicide and Bioinsecticide MCQs Class 12 with Detailed Answers

Bioherbicide and Bioinsecticide MCQs Class 12 is an important biology topic for aspirants who want to understand eco-friendly pest control, biological weed management, natural insecticides, sustainable agriculture, and biotechnology-based crop protection in a clear and exam-focused way. Bioherbicide and Bioinsecticide MCQs Class 12 helps aspirants revise how living organisms, plant products, microbial agents, and natural compounds can be used to control weeds and insect pests without depending completely on harmful synthetic chemicals. This topic is closely connected with microbes in human welfare, biotechnology, ecology, environmental biology, and plant breeding. Bioherbicide and Bioinsecticide MCQs Class 12 is useful for board exams, NEET preparation, agriculture entrance exams, nursing exams, and other biology-based competitive tests.

Bioherbicide and Bioinsecticide MCQs Class 12 becomes easier when aspirants first understand the meaning of bioherbicide. A bioherbicide is a biological agent used to control unwanted plants or weeds. Bioherbicide and Bioinsecticide MCQs Class 12 explains that bioherbicides may include fungi, bacteria, or natural plant-based products that suppress weed growth. Unlike chemical herbicides, bioherbicides are usually more specific and may cause less harm to the surrounding ecosystem. Examples often linked with bioherbicide concepts include Phytophthora palmivora and trade names such as Devine, which has been used for controlling milkweed vine. Bioherbicide and Bioinsecticide MCQs Class 12 helps aspirants remember that bioherbicides support sustainable weed control.

Bioherbicide and Bioinsecticide MCQs Class 12 also explains bioinsecticides. A bioinsecticide is a biological substance or organism used to control insect pests. Bioherbicide and Bioinsecticide MCQs Class 12 is strongly connected with examples such as Bacillus thuringiensis, Chrysanthemum cinerariifolium, rotenone, pyrethrum, and neem-based products. Bacillus thuringiensis, commonly called Bt, produces insecticidal proteins that affect the gut of specific insect larvae. These proteins are encoded by Cry genes and are used in crops such as Bt cotton and Bt brinjal for insect resistance.

Bioherbicide and Bioinsecticide MCQs Class 12 helps aspirants understand why biological pest control is important. Chemical pesticides may kill pests quickly, but excessive use can cause pesticide resistance, biomagnification, soil pollution, water contamination, and harm to beneficial insects. Bioherbicide and Bioinsecticide MCQs Class 12 teaches that bio-based pest control methods are usually safer, more target-specific, and more suitable for integrated pest management. However, aspirants should also remember that bioherbicides and bioinsecticides may work more slowly than chemical pesticides and require suitable environmental conditions for best results.

Bioherbicide and Bioinsecticide MCQs Class 12 is connected with Bt technology. Bt toxin is produced in an inactive protoxin form and becomes active in the alkaline gut of insect larvae. Bioherbicide and Bioinsecticide MCQs Class 12 helps aspirants remember that the activated toxin damages the gut lining, causing insect death. Cry1Ac and Cry2Ab are associated with cotton bollworm control, while Cry1Ab is associated with corn borer control. These examples are frequently tested because they connect microbiology with genetic engineering and crop protection.

Bioherbicide and Bioinsecticide MCQs Class 12 also includes natural insecticides obtained from plants. Rotenone is obtained from the roots of Derris elliptica and is used as an insecticide. Pyrethrum is obtained from Chrysanthemum cinerariifolium and contains compounds useful in pest control. Bioherbicide and Bioinsecticide MCQs Class 12 helps aspirants connect plant sources with insecticidal action. Aspirants should revise the difference between bioinsecticides, biofertilizers, biopesticides, and bioherbicides because these terms are often confused in exams.

Bioherbicide and Bioinsecticide MCQs Class 12 is also useful for understanding organic farming. Organic farming reduces the use of synthetic pesticides and promotes natural pest control, crop rotation, biological control agents, and preservation of beneficial insects. Bioherbicide and Bioinsecticide MCQs Class 12 explains that biological control does not mean complete eradication of all pests; instead, it aims to manage pest populations below harmful levels. This idea is important for ecology because many insects also play useful roles such as pollination, decomposition, and food-chain support.

Bioherbicide and Bioinsecticide MCQs Class 12 should be revised with related terms such as biopesticide, biofertilizer, Bt toxin, Cry gene, rotenone, pyrethrum, Devine, Collego, weed control, insect resistance, pest management, and sustainable agriculture. Bioherbicide and Bioinsecticide MCQs Class 12 becomes stronger when aspirants compare biological agents with chemical agents. Chemical pesticides are often broad-spectrum, while biological agents are usually specific. Specificity helps protect non-target organisms and supports ecological balance.

Bioherbicide and Bioinsecticide MCQs Class 12:

  1. Which type of pathogen is effectively controlled by flooding the field?

A. Fungi
B. Bacteria
C. Nematode
D. Viruses

Answer: C. Nematode

Explanation: Flooding the field can help eliminate nematodes and may be used as an alternative method for nematode control.

  1. Which types of pesticides are included in the category of pesticides?

A. Insecticide only
B. Fungicides, herbicides, insecticides, nematicides, and rodenticides
C. Insecticides, nematicides, and rodenticides
D. Herbicides, insecticides, and nematicides

Answer: B. Fungicides, herbicides, insecticides, nematicides, and rodenticides

Explanation: Pesticides include several types such as fungicides, algicides, herbicides or weedicides, insecticides, nematicides, and rodenticides.

  1. Which part of the cotton plant produces pure cellulose?

A. Root hair
B. Leaf hair
C. Seed hair
D. Stem hair

Answer: C. Seed hair

Explanation: Cotton fibres are produced from the seed hairs of the cotton plant and are made mainly of pure cellulose.

  1. Which pesticide is used as a preventive measure in buildings?

A. Aldrin
B. Dieldrin
C. Endrin
D. DDT

Answer: A. Aldrin

Explanation: Aldrin was used as a soil insecticide and as a preventive measure in buildings against insects such as termites.

  1. Why is the introduction of food plants developed by genetic engineering not desirable?

A. Economy of developing countries may suffer
B. These products are less tasty than already existing products
C. This method is costly
D. There is danger of viruses, allergens, and toxins coming with the introduced crop

Answer: D. There is danger of viruses, allergens, and toxins coming with the introduced crop

Explanation: Genetically engineered food plants require careful safety assessment because there may be risks of allergens, toxins, or other unintended effects.

  1. Which method of cellular defense was used to develop tobacco plants resistant to Meloidogyne incognita?

A. Silencing the translation of specific mRNA
B. Silencing the transcription of specific mRNA
C. Activation of specific tRNA
D. Activation of specific mRNA

Answer: A. Silencing the translation of specific mRNA

Explanation: RNA interference works by silencing specific mRNA using complementary double-stranded RNA, thereby preventing translation.

  1. What is the term for breeding crops with higher levels of vitamins and minerals, higher proteins, or healthier fats?

A. Bio-accumulation
B. Bio-magnification
C. Bio-remediation
D. Bio-fortification

Answer: D. Bio-fortification

Explanation: Biofortification is the process of breeding crops with improved nutritional quality, such as higher vitamin, mineral, protein, or healthy fat content.

  1. Which “new” variety of rice was patented by a foreign company, though such varieties have been present in India for a long time?

A. Co-677
B. Sharbati Sonora
C. Basmati
D. Lerma Rojo

Answer: C. Basmati

Explanation: Basmati rice was involved in a biopiracy-related patent issue, even though such varieties have been cultivated in India for a long time.

  1. Which vaccine is produced by using genetically modified yeast?

A. Polio
B. BCG
C. Hepatitis-B
D. Covaxin

Answer: C. Hepatitis-B

Explanation: Hepatitis-B vaccine is produced using recombinant DNA technology in genetically modified yeast cells.

  1. Enzymes, vitamins, and hormones can be classified into a single category of biological chemicals because all of these

A. Are exclusively synthesized in the body of a living organism at present
B. Enhance oxidative metabolism
C. Are conjugated proteins
D. Help in regulating metabolism

Answer: D. Help in regulating metabolism

Explanation: Enzymes, vitamins, and hormones play important roles in regulating metabolism and maintaining cellular functions.

  1. Tobacco plants resistant to a nematode have been developed by the introduction of DNA that is produced in the host cells as

A. An antifeedant
B. A toxic protein
C. Both sense and anti-sense RNA
D. A particular hormone

Answer: C. Both sense and anti-sense RNA

Explanation: In RNA interference, nematode-specific genes are introduced into the host plant, producing both sense and antisense RNA. These form double-stranded RNA that silences the target mRNA.

  1. Study the following table and identify the correct combinations.

A. RNA interference – Prokaryotes – Cellular defense
B. Genes – Cry1Ab – Controls corn borer
C. Insect – Bt toxin – Active form
D. Superweeds – Gene pollution – Resistance to weedicides

Options:

A. A, C, D
B. B, C, D
C. A, B, D
D. A, B, C

Answer: B. B, C, D

Explanation: Cry1Ab controls corn borer. Bt toxin becomes active in the alkaline gut of insects. Superweeds may arise due to gene pollution and can show resistance to weedicides. RNA interference is mainly found in eukaryotes, not prokaryotes.

  1. Assertion and Reason:

Assertion: Cry is an insect group-specific gene of cotton.
Reason: Cry1Ac and Cry2Ab control cotton bollworms.

A. Assertion is correct, Reason is correct, and Reason is the correct explanation of Assertion
B. Assertion is correct, Reason is correct, but Reason is not the correct explanation of Assertion
C. Assertion is correct, but Reason is false
D. Assertion is false, but Reason is correct

Answer: A. Assertion is correct, Reason is correct, and Reason is the correct explanation of Assertion

Explanation: Cry genes encode Bt toxin proteins. Cry1Ac and Cry2Ab are effective against cotton bollworms, so both assertion and reason are correct.

  1. Which of the following is used as a bioinsecticide?

A. Bacillus polymyxa
B. Cylindrospermum licheniforme
C. Phytophthora palmivora
D. Chrysanthemum cinerariifolium

Answer: D. Chrysanthemum cinerariifolium

Explanation: Chrysanthemum cinerariifolium is the source of pyrethrum, which is used as a natural bioinsecticide.

  1. What is the main purpose of using the gene gun, or biolistic method, in plants?

A. Disarming pathogen vectors
B. Transformation of plant cell
C. Constructing recombinant DNA by joining with vectors
D. DNA fingerprinting

Answer: B. Transformation of plant cell

Explanation: The gene gun method is used to introduce DNA into plant cells by bombarding them with DNA-coated metal particles.

  1. What does the prefix “Bt” in Bt cotton stand for?

A. Barium-treated cotton seeds
B. Bigger thread variety of cotton with better tensile strength
C. Produced by biotechnology using restriction enzymes and ligases
D. Carrying an endotoxin gene from Bacillus thuringiensis

Answer: D. Carrying an endotoxin gene from Bacillus thuringiensis

Explanation: Bt cotton carries an insecticidal toxin gene from the bacterium Bacillus thuringiensis.

  1. Which of the following benefits are associated with gene manipulation in plants?

 

  1. Increased efficiency of mineral usage
  2. Alternative resources to industries
  3. Enhanced nutritional value of food
  4. Better management practices and uses of agrochemicals

Options:

A. II, III, IV
B. I, II, III
C. I, III, IV
D. II, III, IV

Answer: B. I, II, III

Explanation: Gene manipulation in plants can improve mineral usage, provide alternative industrial resources, and enhance the nutritional value of food.

  1. Match the following genetically modified plants with their corresponding traits.

A. Taipei-309
B. Roundup Ready
C. Flavr Savr
D. Bt Cotton

Traits:

I. Bruise resistant and suitable for storage
II. Resistant to cotton bollworm
III. Produces beta-carotene
IV. Resistant to glyphosate herbicide

Options:

A. A-III, B-IV, C-I, D-II
B. A-III, B-I, C-IV, D-II
C. A-III, B-II, C-I, D-IV
D. A-II, B-I, C-III, D-IV

Answer: A. A-III, B-IV, C-I, D-II

Explanation: Taipei-309 is linked with Golden rice and beta-carotene production. Roundup Ready crops are glyphosate resistant. Flavr Savr tomato is bruise resistant and has better storage quality. Bt cotton is resistant to cotton bollworm.

  1. What was the antisense construct of ACC synthase gene RNA used in the production of?

A. Bt maize
B. Bt cotton
C. Golden rice
D. Flavr Savr tomato

Answer: D. Flavr Savr tomato

Explanation: The antisense construct of the ACC synthase gene was used in Flavr Savr tomato to delay ripening by reducing ethylene production.

  1. Which of the following trade names in agriculture is used as a bioherbicide for controlling milkweed vine?

A. DEVINE
B. COLLEGO
C. Phytophthora palmivora
D. Colletotrichum gloeosporioides

Answer: A. DEVINE

Explanation: DEVINE is a bioherbicide used for controlling milkweed vine.

  1. Identify the correct sequence of steps in RNA interference, RNAi, process to develop nematode-resistant plants.

 

  1. Silencing of specific mRNA of the nematode
  2. Formation of sense and antisense RNA
  3. Double-stranded RNA formation
  4. Introducing nematode-specific genes into the plant

Options:

A. IV → II → III → I
B. IV → I → II → III
C. I → II → IV → III
D. III → II → I → IV

Answer: A. IV → II → III → I

Explanation: First, nematode-specific genes are introduced into the plant. Then sense and antisense RNA are formed, which produce double-stranded RNA. This leads to silencing of specific nematode mRNA.

  1. What is the term used for the production of superior F1 hybrids?

A. Inbreeding
B. Domestication
C. Emasculation
D. Heterosis

Answer: D. Heterosis

Explanation: Heterosis refers to the superiority of a hybrid over its parents in one or more traits.

  1. Which of the following statements are incorrect regarding genetically modified crops and related concepts?

A. Genetically modified crops have less tolerance to abiotic stress like heat and drought
B. The proteins encoded by Cry1Ac and Cry2Ab control cotton bollworm, while Cry1Ab controls corn stem borer
C. RNA interference takes place in all organisms as a method of cellular defense
D. Hereditary diseases can be treated through gene therapy

Options:

A. A and C
B. B and C
C. A and D
D. C and D

Answer: A. A and C

Explanation: Genetically modified crops usually show improved tolerance to abiotic stresses such as heat, drought, and salinity. RNA interference occurs in eukaryotic organisms as a cellular defense mechanism, not in all organisms.

  1. Insect pest-resistant Bt cotton plant was developed using which technology?

A. Somaclonal variation
B. Micropropagation
C. Somatic hybridisation
D. Transgenic technology

Answer: D. Transgenic technology

Explanation: Bt cotton is a transgenic plant developed using transgenic technology by introducing Bt toxin genes.

  1. Which of the following is not concerned with biotechnology?

A. Biogas production
B. Sewage treatment
C. Biofertilizers
D. Wood seasoning

Answer: D. Wood seasoning

Explanation: Wood seasoning is the process of reducing the moisture content of wood and is not directly related to biotechnology.

  1. What is hydroponics?

A. Water conservation
B. Plant development in water without soil
C. Agricultural machinery
D. Soil erosion prevention

Answer: B. Plant development in water without soil

Explanation: Hydroponics is the method of growing plants in nutrient-rich water without soil.

  1. Which of the following is a benefit of hydroponics method of plant development?

A. Faster growth rates of crops
B. Complete eradication of pests
C. Preservation of beneficial insects
D. Reduced use of toxic chemicals

Answer: A. Faster growth rates of crops

Explanation: Hydroponics can support faster crop growth by providing nutrients directly through water.

  1. Which of the following is not a benefit of organic farming?

A. Complete eradication of pests
B. Reduced use of toxic chemicals
C. Maintaining an ecosystem in the field
D. Preservation of beneficial insects

Answer: A. Complete eradication of pests

Explanation: Organic farming reduces the use of toxic chemicals and supports beneficial insects, but it does not completely eradicate pests.

  1. Which bio-engineered bacterium is utilized for cleaning marine oil slicks?

A. Escherichia coli
B. Pseudomonas syringae
C. Pseudomonas putida
D. Rhizoctonia solani

Answer: C. Pseudomonas putida

Explanation: Pseudomonas putida is used for breaking down hydrocarbons and cleaning marine oil slicks.

  1. Which insecticide is obtained from the roots of Derris elliptica?

A. Cinerin
B. Nicotine
C. Rotenone
D. Pyrethrum

Answer: C. Rotenone

Explanation: Rotenone is obtained from the roots of Derris elliptica and is used as a broad-spectrum insecticide.

Bioherbicide and Bioinsecticide MCQs Class 12

 

Conclusion on Bioherbicide and Bioinsecticide MCQs Class 12

In conclusion, Bioherbicide and Bioinsecticide MCQs Class 12 is a high-value topic for aspirants preparing biotechnology, ecology, and agriculture-related chapters. Bioherbicide and Bioinsecticide MCQs Class 12 improves understanding of natural weed control, insect pest management, Bt crops, plant-derived insecticides, microbial agents, organic farming, and environmental safety. Bioherbicide and Bioinsecticide MCQs Class 12 helps aspirants connect textbook facts with real agricultural applications. With regular revision, Bioherbicide and Bioinsecticide MCQs Class 12 can help aspirants answer biology questions with better clarity, accuracy, and confidence.

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