Chapter 21, Problem 4STP

Summary Introduction

Introduction:

Vascular seed plants generate seeds. Seed plants have a variety of adaptations for the dispersal or scattering of their seeds throughout their environment. Most seed plants do not require a film of water for their processes; this enables seed plants to thrive in different environments, including areas where water is scarce.

Answer to Problem 4STP

Correct answer :

The correct answer is option (B) Coniferophyta

Explanation of Solution

Explanation/justification for the correct answer :

Option (B) Coniferophyta. Reproductive structures of most conifers develop in cones. Most conifers have male and female cones on different branches of the same tree or shrub. Pollens are release from male cones which are carried by wind. When these pollens settle on a female cone, the female cone will generate seeds. Therefore, the given structure can be found in Coniferophyta. So, the correct answer is option (B).

Explanation for incorrect answer :

Option (A) Anthophyta. Anthophyta are the most widely distributed plants because of adaptations that enable them to grow in terrestrial and aquatic environments. Therefore, the given structure cannot be found in Anthophyta. So, this is an incorrect option.

Option (C) Cycadophyta. Cycadophyta contains male or female reproductive structures of cycads and other gymnosperm plants. Cycad cones can be as long as 1 m and weigh as much as 35 kg. Therefore, the given structure cannot be found in Cycadophyta. So, this is an incorrect answer.

Option (D) Ginkgophyta. Ginkgo biloba is only the species that represents the division Ginkgophyta. This distinctive tree has small, fan-shaped leaves. The male and female reproductive systems are on separate plants. The male tree produces pollen grains in strobilus growing from the bases of leaf clusters and female tree produces cones. Therefore, the given structure cannot be found in Ginkgophyta. So, this is an incorrect answer.