NEET BIOLOGY

Detailed explanation-1: -Vascular plants are subdivided into two classes: seedless plants, which probably evolved first (including lycophytes and pterophytes), and seed plants. Seed-producing plants include gymnosperms, which produce “naked” seeds, and angiosperms, which reproduce by flowering.

Detailed explanation-2: -Plants are classified into two groups: nonvascular plants and vascular plants. Vascular plants are further divided into those that reproduce without seeds and those that reproduce with seeds. Seed plants are divided into those that produce seeds in cones and those that produce seeds in the ovaries of flowers.

Detailed explanation-3: -Nonvascular plants were the first plants to evolve. Compared to other plants, their small size and lack of specialized structures, such as vascular tissue, stems, leaves, or flowers, explains why these plants evolved first. The first nonvascular plants to evolve were the liverworts.

Detailed explanation-4: -Nonvascular plants (often referred to collectively as the bryophytes) include three groups: the mosses (Bryophyta), approximately 15, 000 species; liverworts (Hepaticophyta), approximately 7500 species; and hornworts (Anthocerophyta), approximately 250 species (Table 1).

Detailed explanation-5: -Lycophytes are the oldest group of vascular plants that has living members. They dominated major habitats for 40 million years about 400 million years ago in the paleozoic.