Chapter 29, Problem 33A

Summary Introduction

To explain:

The meaning of alternation of generations as it applies to plants.

Introduction:

Plant reproduction is the method via which plants produce new offspring. Reproduction is both sexual and asexual. Sexual reproduction is the formation of offspring via the fusion of gametes. Asexual duplication is the formation of offspring without the fusion of gametes. Sexual reproduction arises in offspring genetically different from the parents. Asexual offspring are genetically similar except for mutation. In advance plants, offspring are packaged in a protective seed, which may be long lived and might disperse the offspring some distance from the parents.

Explanation of Solution

Plants alternate or exchange between the diploid sporophyte and haploid gametophyte, and between asexual and sexual reproduction. Therefore, the life cycle of plants is referred to as alternation of generations. The capability of the plants to reproduce sexually and asexually allows them to adapt to other environments.

The alternation of generations relies upon the type of the plant. In Bryophytes, the dominant generation is haploid and the gametophyte consists of the main plant. In tracheophytes, the dominant generation is diploid and the sporophyte contains the main plant.

Conclusion

The plants’ life cycle in one of the two generations is dominant over the alternative one. The plants inside the dominant generation grow largely and live longer period of time. The plants in the non-dominant generations are small and often visible. On the contrary, the dominant generations are visible in the shape of ferns, trees or other different kind of plants.