nucellus

简明释义

英[njuːˈseləs]美[ˈnjʊseləs]

n. [植] 珠心

复 数 n u c e l l i

英英释义

单词用法

同义词

反义词

例句

1.There were only two layers of nucellus which had abundant cytoplasm and reserved substance, and were consumed at the stage of late heart-shaped embryo.

珠心细胞只有两层，细胞核大，胞质丰富，内含贮藏物质，至心形胚期逐渐解体。

2.There is no starch in the nucellus, integuments and the antipodal cells, the persistent synergid contains a large amount of starch.

珠心、珠被、反足细胞都不含淀粉。宿存助细胞具丰富的淀粉。

3.About weeks after pollination, the tip cells of nucellus broke and secreted liquid into ovular canal, which promoted pollen movement to the nucellus and played important role for pollen germination.

传粉后约周，珠心顶端破裂，分泌物进入珠孔道，并与珠被分泌物共同作用于花粉，使花粉向珠心移动。

4.Upon further increase of the exogenous hormone concentration, new ovule primordia could be formed from the proliferated nucellus cells, which further developed into many new ovules.

进一步提高外源激素浓度，珠心细胞又可以分化出新的胚珠原基，进一步长大以后发育成许多新的胚珠。

5.After years of observation and assessment on the top-grafting plants of nucellus seedlings, considerable quality variations were found among nucellus embryo plants.

对珠心苗高接植株多年观察及品质鉴定，认为珠心胚植株在品质上表现较大差异。

6.The female archesporium differentiates from the single cell under the epidermis of nucellus.

雌性孢原处于珠心表皮之下，为单细胞。

7.About 4 weeks after pollination, the tip cells of nucellus broke and secreted liquid into ovular canal, which promoted pollen movement to the nucellus and played important role for pollen germination.

传粉后约4周，珠心顶端破裂，分泌物进入珠孔道，并与珠被分泌物共同作用于花粉，使花粉向珠心移动。

8.The integument grew fast and overgrew the nucellus.

珠被生长较快，并逐渐包围珠心。

9.The nucellus is usually degraded and absorbed as the endosperm develops.

珠心通常在胚乳发育时被分解和吸收。

10.About 4 weeks after pollination, the tip cells of nucellus broke and secreted liquid into ovular canal, which promoted pollen movement to the nucellus and played important role for pollen germination.

传粉后约4周，珠心顶端破裂，分泌物进入珠孔道，并与珠被分泌物共同作用于花粉，使花粉向珠心移动。

11.Researchers study the genetic material within the nucellus 胚乳 to improve crop yields.

研究人员研究nucellus 胚乳中的遗传材料，以提高作物产量。

12.The nucellus 胚乳 plays a crucial role in the formation of the embryo.

在胚胎形成中，nucellus 胚乳起着至关重要的作用。

13.During fertilization, the sperm travels to the nucellus 胚乳 to fertilize the egg cell.

在受精过程中，精子游向nucellus 胚乳以受精卵细胞。

14.In gymnosperms, the nucellus 胚乳 is often surrounded by a hard seed coat.

在裸子植物中，nucellus 胚乳通常被坚硬的种皮包围。

15.The seed's development begins in the female ovule, where the nucellus 胚乳 provides nutrients.

种子的发育始于雌性胚珠，在那里nucellus 胚乳提供养分。

作文

The term nucellus refers to the central part of a seed or ovule in plants, where the reproductive cells are located. This structure plays a crucial role in the life cycle of flowering plants, particularly in the process of fertilization and seed development. Understanding the function of the nucellus is essential for botanists and horticulturists alike, as it provides insight into plant reproduction and genetic diversity.In the world of botany, the nucellus is often described as the tissue that surrounds the embryo sac, which contains the egg cell and other important cells involved in reproduction. The nucellus is usually made up of parenchyma cells, which are specialized for storage and support. These cells not only protect the developing gametes but also provide them with the necessary nutrients for growth and development.When a pollen grain lands on the stigma of a flower, it germinates and forms a pollen tube that travels down the style to reach the ovule. This is where the magic of fertilization occurs. The sperm cells from the pollen travel through the pollen tube and enter the ovule, where one sperm fertilizes the egg cell, while another may fuse with two polar nuclei to form the triploid endosperm. This process is vital for the formation of seeds, which are essential for the propagation of flowering plants.The nucellus is not just a passive structure; it actively participates in the development of the ovule and the seed. After fertilization, the nucellus can undergo changes that lead to the formation of the seed coat. In some species, the nucellus itself can contribute to the seed's nutritional content, further emphasizing its importance in plant reproduction.Moreover, the study of the nucellus can provide valuable information about plant evolution and adaptation. By examining the structure and function of the nucellus across different plant species, scientists can gain insights into how plants have evolved to reproduce efficiently in various environments. For example, certain adaptations in the nucellus may allow plants to thrive in arid conditions by optimizing water and nutrient use.In conclusion, the nucellus is a vital component of plant reproduction, serving as the site for fertilization and the initial stages of seed development. Its role in protecting and nourishing the reproductive cells cannot be overstated. As we continue to explore the complexities of plant biology, the nucellus will undoubtedly remain a key focus of research, shedding light on the intricate processes that sustain life on Earth. Understanding the nucellus not only enhances our knowledge of botany but also has practical implications for agriculture and conservation efforts, ensuring that we can maintain biodiversity and food security for future generations.

术语nucellus指的是植物种子或胚珠的中心部分，在这里生殖细胞被定位。这个结构在开花植物的生命周期中发挥着至关重要的作用，特别是在受精和种子发育的过程中。理解nucellus的功能对于植物学家和园艺师来说都是至关重要的，因为它提供了关于植物繁殖和遗传多样性的深入见解。在植物学的世界里，nucellus通常被描述为包围胚囊的组织，胚囊中包含卵细胞和其他参与繁殖的重要细胞。nucellus通常由薄壁细胞组成，这些细胞专门用于储存和支持。这些细胞不仅保护发育中的配子，还为其生长和发育提供必要的营养。当花粉粒落在花的柱头上时，它会萌发并形成一根花粉管，沿着花柱向下移动以到达胚珠。这就是受精发生的地方。来自花粉的精子细胞通过花粉管进入胚珠，其中一个精子使卵细胞受精，而另一个可能与两个极核融合形成三倍体胚乳。这个过程对种子的形成至关重要，而种子是开花植物繁殖的基础。nucellus不仅仅是一个被动的结构；它还积极参与胚珠和种子的发育。在受精后，nucellus可以经历变化，导致种皮的形成。在某些物种中，nucellus本身可以为种子的营养成分做出贡献，进一步强调了它在植物繁殖中的重要性。此外，研究nucellus可以提供有关植物进化和适应的宝贵信息。通过检查不同植物物种中nucellus的结构和功能，科学家可以获得关于植物如何在各种环境中有效繁殖的见解。例如，nucellus的某些适应可能使植物能够在干旱条件下生存，从而优化水分和营养的使用。总之，nucellus是植物繁殖的重要组成部分，作为受精和种子发育初始阶段的场所。它在保护和滋养生殖细胞方面的作用不容小觑。随着我们继续探索植物生物学的复杂性，nucellus无疑将仍然是研究的关键焦点，为维持地球生命的复杂过程提供启示。理解nucellus不仅增强了我们对植物学的知识，还有助于农业和保护工作，确保我们能够为未来几代人保持生物多样性和粮食安全。