Select the incorrect statement from the following

The correct option is: notochord and ventral hollow neural system are a common feature of the phylum chordata

To determine the incorrect statement, let us analyze each of the given options step-by-step:
1. Taxonomic studies are useful in agriculture, forestry, and industries: This is a correct statement. Understanding taxonomy helps in identifying and classifying plants, animals, and microbes, which is fundamental to forestry, agriculture, pest management, and industries relying on bio-resources.
2. Closely related species differ in morphological features: This is a correct statement. While closely related species within the same genus share many evolutionary similarities, they must have distinct, observable morphological differences that justify classifying them as separate species.
3. Notochord and ventral hollow neural system are a common feature of the phylum chordata: This statement is incorrect. Phylum Chordata is characterized by three fundamental features: a notochord, a dorsal hollow nerve cord (neural system), and paired pharyngeal gill slits. The neural tube or nerve cord in chordates is positioned dorsally (along the back), not ventrally (along the belly). A ventral, solid, and double nerve cord is characteristic of non-chordate invertebrates.
4. Genus comprises a group of related species: This is a correct statement. A genus is a taxonomic category that groups together species that have more characteristics in common with each other than with species of other genera.

Since the question asks to select the incorrect statement, the correct answer is the statement describing a ventral hollow neural system in chordates.