alternation of generations

简明释义

世代交替;

英英释义

例句

1.Ferns are an excellent example of alternation of generations, as they have distinct sporophyte and gametophyte phases.

蕨类植物是世代交替的一个很好的例子，因为它们有明显的孢子体和配子体阶段。

2.Many mosses exhibit alternation of generations, where the dominant stage is the gametophyte.

许多苔藓表现出世代交替，其中主导阶段是配子体。

3.The alternation of generations is crucial for understanding how different species reproduce and evolve over time.

世代交替对于理解不同物种如何繁殖和随着时间演化是至关重要的。

4.In plants, the process of alternation of generations refers to the lifecycle that includes both a haploid gametophyte stage and a diploid sporophyte stage.

在植物中，世代交替的过程指的是包括单倍体配子体阶段和二倍体孢子体阶段的生命周期。

5.The study of alternation of generations helps scientists understand the genetic diversity in plant populations.

对世代交替的研究帮助科学家理解植物种群中的遗传多样性。

作文

The concept of alternation of generations is fundamental in understanding the life cycles of many organisms, particularly in the plant kingdom. This biological phenomenon refers to the occurrence of two distinct multicellular stages in the life cycle of an organism: the haploid stage, known as the gametophyte, and the diploid stage, known as the sporophyte. Each generation gives rise to the other, hence the term alternation of generations, which highlights the cyclical nature of these life forms. In plants, the alternation of generations begins with the sporophyte, which produces spores through meiosis. These spores are haploid and can develop into gametophytes. The gametophyte then produces gametes through mitosis, which are also haploid. When two gametes fuse during fertilization, they form a diploid zygote that develops into a new sporophyte, thus continuing the cycle. This process is not only fascinating but also crucial for the survival and adaptation of plant species. For example, in mosses, the gametophyte is the dominant generation, while in flowering plants, the sporophyte is more prominent. Understanding the alternation of generations helps us appreciate how different plants have evolved to thrive in various environments. Moreover, the implications of alternation of generations extend beyond botany. This concept is also observed in certain algae and fungi, where the life cycle involves similar stages. In these organisms, the balance between the haploid and diploid phases can influence reproductive strategies and ecological dynamics. In summary, the alternation of generations is a key concept in biology that illustrates the complexity and diversity of life cycles among various organisms. By studying these processes, we gain insights into evolutionary adaptations, ecological interactions, and the fundamental principles of life itself. As we delve deeper into the mechanisms of alternation of generations, we uncover the intricate relationships that sustain ecosystems and the evolutionary pathways that shape the biodiversity we observe today.

‘世代交替’这一概念在理解许多生物体的生命周期，尤其是在植物王国中是基础性的。这个生物现象指的是生物的生命周期中出现两个不同的多细胞阶段：单倍体阶段，称为配子体，以及二倍体阶段，称为孢子体。每一代都会产生另一代，因此称为‘世代交替’，强调了这些生命形式的循环特性。在植物中，‘世代交替’始于孢子体，它通过减数分裂产生孢子。这些孢子是单倍体的，可以发育成配子体。然后，配子体通过有丝分裂产生配子，这些配子也是单倍体。当两个配子在受精过程中结合时，会形成一个二倍体的合子，进而发育成新的孢子体，从而继续循环。这个过程不仅令人着迷，而且对植物物种的生存和适应至关重要。例如，在苔藓中，配子体是占主导地位的世代，而在开花植物中，孢子体更为突出。理解‘世代交替’帮助我们欣赏不同植物如何进化以在各种环境中茁壮成长。此外，‘世代交替’的影响超越了植物学。这个概念也出现在某些藻类和真菌中，这些生物的生命周期涉及类似的阶段。在这些生物中，单倍体和二倍体阶段之间的平衡可以影响繁殖策略和生态动态。总之，‘世代交替’是生物学中的一个关键概念，展示了各种生物体生命周期的复杂性和多样性。通过研究这些过程，我们获得了关于进化适应、生态互动和生命基本原则的见解。当我们深入探讨‘世代交替’的机制时，我们揭示了维持生态系统的复杂关系以及塑造我们今天所观察到的生物多样性的进化路径。