Plant Biology and Classification

Species is the fundamental unit of biological classification. A species is a group of organisms that can interbreed and produce fertile offspring, representing the most specific level in the taxonomic hierarchy.

Cryptogams are flowerless and seedless plants that reproduce via spores. The term comes from Greek 'crypto' (hidden) and 'gamos' (marriage), referring to their hidden reproduction. They include algae, fungi, bryophytes, and pteridophytes.

The three main groups of cryptogams (flowerless, seedless plants) are Thallophyta (simple plants like algae), Bryophyta (mosses and liverworts), and Pteridophyta (ferns). They all reproduce via spores rather than seeds.

Bryophytes like mosses and liverworts bear spores in capsules called sporangia. These spore-containing capsules are a distinguishing feature of non-vascular plants. Cycas and Nephrolepis are vascular plants, while lichen and mushroom are fungi.

Bryophytes such as mosses and liverworts possess rhizoids that resemble roots but lack true vascular tissues, earning them the description of having false roots. These are among the simplest non-vascular plants.

In biological classification hierarchy, kingdom is the highest and most comprehensive category. All phyla (for animals) or divisions (for plants) are grouped into kingdoms. The hierarchy from broadest to most specific is: Kingdom > Phylum/Division > Class > Order > Family > Genus > Species.

Gymnosperms are classified into cycadales and coniferales.

The plant kingdom is traditionally divided into two main groups: cryptogams (plants with hidden reproductive structures like algae, fungi, bryophytes, pteridophytes) and phanerogams (plants with visible reproductive structures). Phanerogams include gymnosperms and angiosperms (also called spermatophyta).

A genus is a taxonomic category that groups species sharing similar characteristics, especially in their reproductive organs. Species within the same genus are closely related and can often hybridize. Genus ranks above species but below family in the classification hierarchy.

Sentences C and D can easily be paired together on account of common reference to Swedish botanist and later D and B can be paired on account of common reference to Latin language. Also, sentences A and 6 can be paired on account of common reference to the number of plants and therefore, option (3) validates all our inferences. Thus, option (3) is correct answer.

The cell sap in members of compositae has a unique chemical known as insulin.

The area of the plant embryo between the cotyledons and the radicle is called the hypcotyl.

In some plants, the ovary has only one chamber despite consisting of several fused carpels. In these plants, the placenta is central and called free central placentation.

In parietal placentation, the placenta is present on the outer wall of ovary.

Holoparasites are those plants which obtain their total food (organic food, water and minerals) from the host. These plants have no chlorophyll and referred as nonchlorophyllous plants, i.e.,  Cuscuta, Sparia, Balanphora, Striga, Orobanche, etc. Semi or partial parasites are those plants which have chlorophyll. So they can synthesize their own organic food (carbohydrate) but the depend on the host for water as well as minerals, i.e.,  Loranthus, Viscum, Santalum, etc.