Question

The seed plants are also known as a. bryophytes. b. spermatophytes. c. pteridophytes. d. lycophytes. e. none of the above

Short answer

The seed plants are also known as spermatophytes.

Step-by-step solution

Identifying the Correct Term

From the options provided, the term that is also used to refer to 'seed plants' is 'spermatophytes.' The term spermatophyte is derived from the Greek words 'sperma' meaning seed and 'phyte' meaning plant. Therefore, this term directly refers to plants that produce seeds. The other options - bryophytes, pteridophytes, and lycophytes, refer to different divisions of plants, none of which are specifically associated with seed production. 'None of the above' would only be correct if none of the given options was the correct term for seed plants, which is not the case here.

Key concepts

Seed Plants

Seed plants, also known as spermatophytes, are a major division of the plant kingdom and are characterized by their ability to produce seeds. Seeds are the plant's reproductive units, containing the embryo and the storage tissue to nourish it. This adaptation has allowed seed plants to dominate many terrestrial ecosystems.

• Spermatophytes include both gymnosperms and angiosperms.
• Gymnosperms are typically cone-bearing plants like pines and firs, with seeds exposed on the surface of cone scales.
• Angiosperms, or flowering plants, have seeds enclosed within fruits and are more diverse, including trees, shrubs, and flowers.

Seed production provides these plants with several advantages: protection from desiccation, a food supply for the developing embryo, and mechanisms for dispersion, such as via wind or animals.

Bryophytes

Bryophytes are a group of non-vascular plants, which means they do not have the vascular tissues (xylem and phloem) that most other plants use for the transport of water and nutrients. This group includes mosses, liverworts, and hornworts.
Bryophytes are quite distinct from seed plants due to several key characteristics:

• They reproduce via spores rather than seeds.
• They require a moist environment for reproduction, as their sperm must swim through water to reach the egg.
• They have a simple body structure that absorbs water and nutrients directly from their environment.

Bryophytes play an essential role in their ecosystems by helping to prevent erosion, retaining moisture, and serving as indicators of environmental health.

Pteridophytes

Pteridophytes are vascular plants like ferns, horsetails, and whisk ferns, but they do not produce seeds. Instead, they reproduce by releasing spores, akin to bryophytes.
Pteridophytes have several features distinguishing them from seed plants:

• They have vascular tissues for the transport of water and nutrients, enabling them to grow larger and thrive in various environments.
• Ferns, a well-known group within pteridophytes, possess fronds which are large, divided leaves that aid in photosynthesis.
• They have a life cycle dominated by the sporophyte stage, which is the visible and larger plant.

Pteridophytes often occupy shady, moist environments, contributing to the understory of forests and assisting in soil formation.

Lycophytes

Lycophytes, which include club mosses, quillworts, and spike mosses, are among the oldest groups of vascular plants. These plants are significantly different from seed plants in various ways.
Some of their key features include:

• Lycophytes have small, simple leaves known as microphylls.
• They reproduce through spores, not seeds, similar to bryophytes and pteridophytes.
• Lycophytes typically have a unique structure called a strobilus, a cone-like formation for spore production.

Historically, lycophytes were much more prominent, with some tree-sized forms flourishing in the Paleozoic era. Today, they are smaller but still play a critical role in various ecosystems, often found in tropical and subtropical regions.