Plant Biology and Classification

Binomial nomenclature involves a generic epithet, a specific epithet, Latin language usage, and specific formatting rules like italics or underlining. All four listed features are standard components of the system.

Nomenclature is application of correct name to plants and taxonomic rank under the rule as drawn by ICBN (International Code for Botanical Nomenclature); option A is incorrect and B is correct. Scientific names formulated in Latin language are preferred over those in vernacular languages due to restricted use and application of these names in one or two languages and non-availability of vernacular names for all known plant species; this makes option C incorrect. Scientific names are not formulated in English but in Latin because latter one is a dead language and the meanings of words are not prone to changes as is the case with English; this makes option D incorrect. Thus, the correct answer is option B.

Scientific names are derived from Latin language. This is because it is a dead language and the meanings of words are not prone to changes.

The art of naming an object is, in fact, a science called nomenclature. Binomial nomenclature is followed worldwide to identify an organism. Every organism has a scientific name, which is a combination of genus and species. Most of these names are in the Latin language. For example, the scientific name of human is Homo sapiens and that of frog is Rana tigrina.

Algae, bryophytes, pteridophytes, gymnosperms, and angiosperms are all members of the domain Eukaryota.

Thigmotropism is the growth or movement of a plant in response to touch. The telegraph plant (Codariocalyx motorius) exhibits rapid leaf movement in response to touch/vibration.

Thigmotropism- In this type of tropic movement stimulus is touch or contact. This type of movement helps weak stem of vines and climbers to coil around the support with the help of tendrils.

In Funaria, 32 peristomial teeth are present. It consists of two sets of long, conical teeth, one within the other. There are 16 teeth in each set. It follows hygroscopic path where moisture is absorbed or attracted from air.

Phototactic movement is movement of organisms influenced by light. Low intensiti of light induces positive phototactic movement in algae.

Thigmonasty is the response of a plant to touch or vibration. The Venus Flytrap an insectivorous plant shows thigmonasty. When an insect lands on its trap, the tentacles present on the two curved lobes of a single leaf, rapidly close. Hence the insect gets trapped and later killed. Thus the correct answer is option C.

Nyctinasty is the rhythmic nastic movement shown by plant in response to onset of darkness. Chemonasty is the nastic movement shown by plant in response to external chemical stimuli. Antherozoids are attracted towards archegonia in a fern plant due to chemonastic movement. Thigmonasty is the nastic movement shown by plant in response to the touch. Seismonasty is the nastic movement shown by plant in response to the vibration.

When the marginal glandular hair of Drosera leaf comes in contact with the insect body, they show thigmonastic (haptonastic) movement. It is the nastic movement (paratonic variation movement) determined by the external stimulus of touch or contact but the direction of movement is prefixed, determined by the structure of the responsive organ. Thus the correct answer is option C.

Azolla pinnata is an aquatic fern, which contains a nitrogen-fixing cyanobacteria. It contains Anabaena azollae in its leaf cavities. It is an excellent biofertilizer for paddy fields because they can fix nitrogen in moist condition also.