Chapter 26, Problem 38A

Summary Introduction

To determine:

The comparison between alternation of generations in plants and jellyfish.

Introduction:

Alternation of generations is referred to a phenomenon, which occurs in many organisms, mostly in plants, in which they have two different life forms in a single life cycle. Plant showing alternation of generations can exist in two phases gametophyte and the sporophyte.

Explanation of Solution

Plant showing alternation of generations can exist in two phases gametophyte and the sporophyte. Alternation of generations is referred to as a phenomenon, which occurs in many organisms, mostly in plants, in which they have two different life forms in a single life cycle.

In the alteration of the generation, the spores develop in haploid gametophyte, the gametophyte is the haploid. This gametophyte give rise to the male and female gamete by the process of mitosis. The fertilization of the male and the female gamete gives rise to the diploid sporophyte. This sporophyte can undergo meiotic division, which produces spores.

In the jelly fish, the alternation of generation is divided into two phases, medusa and polyp. The polyp phase of the jellyfish is polyploid and the animals in this phase consist of a tentacle and stalk. The tentacles are used for feeding. The stalk is adhered to the surfaces and present is sessile form. They can produce more buds, which can asexually form more polyps.

The second stage of the polyp is medusa, in which the polyps asexually produce jellyfish, it is a mobile forma and feed on planktons. The medusa form can reproduce by spawning.