Chapter 21, Problem 22A

Summary Introduction

Introduction :

The spore-producing process in the life cycle of a plant is called sporophyte. There are 2 reproductive stages in plants: sexual and asexual. The alternation of generation secretes these two phases into the sporophyte and gametophyte via the cycle of meiosis and fertilization. Sporophyte is the phase when plants produce diploid (2n) spores which develop into gametophytes in turn to spores.

Answer to Problem 22A

Correct answer :

The correct answer is option (D) rhizoid.

Explanation of Solution

Explanation/justification for the correct answer :

Option (D) rhizoid. The formation of rhizoids is observed in mosses and liverworts. It is a filamentous outgrowth or root hairs below the thallus. It involve in conduction of water and serves as anchor to the plants. So, the correct answer is option (D).

Explanation for incorrect answer :

Option (A) rhizome. Rhizome is a food storage organ of fern. They are the thick underground stems and roots produced by sporophytes. So, this is an incorrect option.

Option (B) sorus. Sorus is a structure that forms from a cluster of sporangia in ferns. Because of this structure the ferns shows horsetail like leaves. So, this is an incorrect answer.

Option (C) frond. Frond is a photosynthetic leafy structures. It is a part of sporophyte generation that have branched vascular tissue of different size. So, this is an incorrect answer.