Chapter 21, Problem 31A

Summary Introduction

Introduction :

Vascular seed plants produce seeds. Each seed contains a tiny sporophyte surrounded by a protective tissue. Plants whose seeds are part of fruits are called angiosperms and those plants whose seeds are not part of fruits are called gymnosperms.

Answer to Problem 31A

Correct answer :

The correct answer is option (D) Ginkophyta.

Explanation of Solution

Explanation/justification for the correct answer :

Option (D) Ginkophyta. The division Ginkophyta is represented by only one living species, Ginko biloba. 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 like cones growing from the bases of leaf clusters. The female tree produces cones which when fertilized, develop foul smelling, fleshy seed coats. So, the correct answer is option (D).

Explanation for incorrect answer :

Option (B) Coniferophyta. Reproductive structures of most conifers develop in cones. The male and female cones develop on different branches of the same tree. The female cones are larger and can be described as woody, berry-like or fleshy. The above picture is not the reproductive structure of coniferophyta. So, this is an incorrect option.

Option (C) Anthophyta. Due to the adaptations that allow them to develop in terrestrial and aquatic environments, anthophytes are the most distributed plants. They include monocot and dicot plants. About 75% of the anthophytes are eudicots and include many trees, shrubs, and garden plants. The given image is of the reproductive structures of ginkophyta that grow from the base of leaf clusters. So, this is an incorrect answer.

Option (D) Gnetophyta. Plants belonging to Gnetophyta can live for up to 1500-2000 years. There are only three genera of gnetophytes, each with unique structural changes to their environment. The above image is of the reproductive structures of Ginkophyta that grow from the base of leaf clusters. So, this is an incorrect answer.