endosymbiont

简明释义

英[ˌendəʊˈsɪmbɪˌɒnt]美[en'dosɪmbjənt]

n. [生态] 内共生体

英英释义

单词用法

同义词

反义词

例句

1.A second endosymbiont, found in aphids, illustrates another possible fate for the genes of a hanger-on.

在蚜虫中发现的另外一种内共生体则阐明了必须基因的另一种可能的命运。

2.A second endosymbiont, found in aphids, illustrates another possible fate for the genes of a hanger-on.

在蚜虫中发现的另外一种内共生体则阐明了必须基因的另一种可能的命运。

3.The green algae in the cells of the coral are a type of endosymbiont (内共生体) that provides nutrients through photosynthesis.

珊瑚细胞中的绿藻是一种类型的endosymbiont（内共生体），通过光合作用提供养分。

4.Some insects rely on endosymbionts (内共生体) to digest cellulose from the plants they consume.

一些昆虫依赖于endosymbionts（内共生体）来消化它们所吃植物中的纤维素。

5.The study of endosymbionts (内共生体) has provided insights into evolutionary biology.

对endosymbionts（内共生体）的研究为进化生物学提供了见解。

6.In some marine environments, endosymbionts (内共生体) play a crucial role in nutrient cycling.

在某些海洋环境中，endosymbionts（内共生体）在养分循环中起着关键作用。

7.The relationship between the host and its endosymbionts (内共生体) is often mutualistic.

宿主与其endosymbionts（内共生体）之间的关系通常是互利共生的。

作文

The concept of the endosymbiont is a fascinating one that has significantly shaped our understanding of cellular biology and evolution. An endosymbiont refers to an organism that lives within the body or cells of another organism in a mutually beneficial relationship. This term is particularly important in explaining the origin of certain organelles within eukaryotic cells, such as mitochondria and chloroplasts. The endosymbiotic theory posits that these organelles were once free-living prokaryotic organisms that entered into a symbiotic relationship with ancestral eukaryotic cells. Over time, these prokaryotes became integrated into the host cell, evolving into the organelles we recognize today. The idea of endosymbionts challenges traditional views of how complex life forms evolved. Instead of solely relying on gradual mutations and natural selection, the endosymbiotic theory suggests that significant evolutionary leaps can occur through symbiotic relationships. For example, the incorporation of a photosynthetic bacterium into a eukaryotic cell would have provided the host with the ability to harness sunlight for energy, leading to the development of plants. Similarly, the engulfment of a respiratory bacterium would have allowed early eukaryotes to utilize oxygen more efficiently, paving the way for more complex life forms. Research supporting the endosymbiotic theory includes genetic and biochemical evidence. Mitochondria and chloroplasts contain their own DNA, which is distinct from the nuclear DNA of the host cell. This DNA closely resembles that of certain bacteria, indicating a shared ancestry. Additionally, these organelles replicate independently of the cell cycle, further supporting their origins as free-living organisms. The presence of double membranes around mitochondria and chloroplasts also aligns with the idea that they were once engulfed by a larger cell. Understanding the role of endosymbionts extends beyond just the origins of organelles; it also has implications for ecology and evolution. Many organisms today rely on endosymbionts for essential functions. For instance, corals depend on photosynthetic algae called zooxanthellae, which live within their tissues, providing them with energy through photosynthesis. In return, the algae receive protection and access to sunlight. This mutualistic relationship is critical for the health of coral reefs, which are among the most diverse ecosystems on the planet. Furthermore, humans also harbor various endosymbionts, particularly in our gut microbiota. These microorganisms play a vital role in digestion, synthesizing vitamins, and protecting against pathogens. The balance of these microbial communities can significantly impact our health, influencing everything from metabolism to immune responses. This underscores the importance of understanding endosymbionts not only in a biological context but also in terms of their ecological and health-related implications. In conclusion, the study of endosymbionts offers profound insights into the complexity of life on Earth. It highlights the intricate relationships that exist between different organisms and emphasizes the importance of cooperation in evolution. As we continue to explore the roles of these fascinating entities, we may uncover even more about the interconnectedness of life and the evolutionary processes that have shaped our world. The legacy of endosymbionts is a testament to the power of collaboration in nature, reminding us that sometimes, the most significant advancements arise from unexpected partnerships.

内共生体的概念是一个迷人的主题，它在很大程度上塑造了我们对细胞生物学和进化的理解。endosymbiont指的是一种生物，它生活在另一种生物的体内或细胞内，并建立互惠互利的关系。这个术语在解释真核细胞中某些细胞器的起源时尤为重要，例如线粒体和叶绿体。内共生理论认为，这些细胞器曾经是自由生活的原核生物，它们与祖先真核细胞进入了一种共生关系。随着时间的推移，这些原核生物逐渐融入宿主细胞，演变成我们今天所认识的细胞器。 内共生体的概念挑战了传统的复杂生命形式进化观念。内共生理论表明，显著的进化飞跃可以通过共生关系发生，而不仅仅依赖于渐进的突变和自然选择。例如，将光合细菌纳入真核细胞将使宿主能够利用阳光进行能量转化，从而导致植物的发展。类似地，吞噬呼吸细菌将使早期真核生物更有效地利用氧气，为更复杂生命形式的出现铺平道路。 支持内共生理论的研究包括遗传和生化证据。线粒体和叶绿体含有自己的DNA，这些DNA与宿主细胞的核DNA不同。这些DNA与某些细菌的DNA密切相关，表明它们有共同的祖先。此外，这些细胞器独立于细胞周期进行复制，进一步支持它们作为自由生活生物的起源。线粒体和叶绿体周围存在双层膜的现象也符合它们曾被更大细胞吞噬的观点。 理解内共生体的角色不仅限于细胞器的起源；它还对生态学和进化有影响。许多今天的生物依赖于内共生体来完成基本功能。例如，珊瑚依赖于称为虫黄藻的光合藻类，这些藻类生活在它们的组织内，通过光合作用为它们提供能量。作为回报，藻类获得保护和阳光的接触。这种互惠关系对珊瑚礁的健康至关重要，珊瑚礁是地球上最丰富的生态系统之一。 此外，人类也携带各种内共生体，特别是在我们的肠道微生物群中。这些微生物在消化、合成维生素和保护宿主免受病原体侵害方面发挥着重要作用。这些微生物群落的平衡会显著影响我们的健康，影响从新陈代谢到免疫反应的方方面面。这强调了理解内共生体的重要性，不仅在生物学背景下，也在其生态和健康相关影响方面。 总之，内共生体的研究为我们提供了对地球生命复杂性的深刻见解。它突显了不同生物之间存在的复杂关系，并强调了合作在进化中的重要性。随着我们继续探索这些迷人实体的角色，我们可能会发现更多关于生命相互关联性和塑造我们世界的进化过程的信息。内共生体的遗产证明了自然界中合作的力量，提醒我们，有时，最重要的进步来自意想不到的伙伴关系。