The correct answer is D. 1, 2 and 3.
Bacteria, fungi, and flowering plants are all examples of organisms that can be used as biopesticides. Biopesticides are pesticides that are derived from natural sources, such as plants, animals, or microorganisms. They are often used as an alternative to synthetic pesticides, which can be harmful to the environment and human health.
Bacteria can be used as biopesticides in a number of ways. Some bacteria produce toxins that can kill pests, while others can compete with pests for food or space. For example, the bacterium Bacillus thuringiensis (Bt) produces a toxin that is lethal to certain insects, such as mosquitoes and caterpillars. Bt is widely used as a biopesticide in agriculture.
Fungi can also be used as biopesticides. Some fungi produce toxins that can kill pests, while others can parasitize pests. For example, the fungus Metarhizium anisopliae can kill a variety of insects, including mosquitoes, flies, and beetles. M. anisopliae is commercially available as a biopesticide.
Flowering plants can also be used as biopesticides. Some plants produce chemicals that can repel or kill pests. For example, the neem tree produces a chemical called azadirachtin, which can repel a variety of insects. Azadirachtin is commercially available as a biopesticide.
In conclusion, bacteria, fungi, and flowering plants are all examples of organisms that can be used as biopesticides. Biopesticides are pesticides that are derived from natural sources, such as plants, animals, or microorganisms. They are often used as an alternative to synthetic pesticides, which can be harmful to the environment and human health.