diplotene

简明释义

英[ˌdɪpləˈtiːn]美[ˌdɪpləˈtiːn]

n. 双线期

adj. 双线期的

英英释义

单词用法

同义词

反义词

例句

1.Prophase may be divided into successive stages termed leptotene, zygotene, pachytene, diplotene, and diakinesis.

前期可被分为连续的阶段：细线期、偶线期、粗线期、双线期和终变期。

2.In diplotene the pairs of chromatids begin to separate from the tetrad formed by the association of homologous chromosomes.

双线期时，配对的染色单体开始从四分体中分离，此时常可见染色体交叉。

3.In diplotene the pairs of chromatids begin to separate from the tetrad formed by the association of homologous chromosomes.

双线期时，配对的染色单体开始从四分体中分离，此时常可见染色体交叉。

4.During diplotene, the synaptonemal complex disassembles, allowing for genetic recombination.

在diplotene阶段，突触复合体解体，允许进行基因重组。

5.Research has shown that the duration of the diplotene phase can vary significantly between different species.

研究表明，不同物种之间diplotene阶段的持续时间可能有显著差异。

6.In the diplotene stage, the homologous chromosomes become more distinct and can be observed under a microscope.

在diplotene阶段，同源染色体变得更加明显，可以在显微镜下观察到。

7.During meiosis, the chromosomes are in the phase known as diplotene, where they begin to separate but are still connected at chiasmata.

在减数分裂过程中，染色体处于被称为diplotene的阶段，此时它们开始分离，但仍通过交叉点连接。

8.The cell cycle is crucial for understanding when the diplotene stage occurs during gamete formation.

细胞周期对于理解在配子形成过程中何时发生diplotene阶段至关重要。

作文

In the intricate world of genetics, understanding the stages of meiosis is crucial for grasping how organisms reproduce and pass on their genetic material. One of the lesser-known but significant stages of meiosis is called diplotene. This term refers to a specific phase during prophase I of meiosis, where homologous chromosomes begin to separate. In this essay, we will explore the importance of diplotene in the context of genetic diversity and reproduction.During meiosis, a diploid cell undergoes two rounds of division to produce four haploid cells. The first round, known as meiosis I, consists of several phases: leptotene, zygotene, pachytene, diplotene, diakinesis, and finally metaphase I. Each of these stages plays a critical role in ensuring that genetic material is accurately divided and recombined. Specifically, diplotene is characterized by the gradual separation of homologous chromosomes, which are pairs of chromosomes that contain the same genes but may have different alleles.The significance of diplotene lies in its role in the process of crossing over, which occurs during the preceding stage, pachytene. During crossing over, segments of DNA are exchanged between homologous chromosomes, leading to genetic recombination. This process is essential for increasing genetic diversity within a population. When diplotene occurs, the chromosomes are still held together at points called chiasmata, where the crossing over has taken place. This allows for the exchange of genetic material while also ensuring that the chromosomes remain aligned correctly as they prepare for separation.Furthermore, diplotene is not only important for genetic diversity but also for the proper segregation of chromosomes. If errors occur during this stage, it can lead to aneuploidy, a condition where cells have an abnormal number of chromosomes. Aneuploidy can result in various genetic disorders, such as Down syndrome, which is caused by the presence of an extra copy of chromosome 21. Thus, understanding diplotene and its implications is vital for both basic biology and medical research.In many species, including humans, diplotene can last for an extended period, sometimes even years. For example, in human females, oocytes can remain in diplotene for decades until ovulation occurs. This prolonged pause highlights the complexity of reproductive biology and the careful regulation of meiotic processes. It also raises interesting questions about the factors that influence the timing of meiosis and how environmental conditions might affect fertility.In conclusion, the stage of diplotene in meiosis is a critical juncture that facilitates genetic diversity and ensures the accurate distribution of chromosomes during cell division. By understanding this phase, scientists can gain insights into the mechanisms of reproduction and the potential causes of genetic disorders. As research continues to evolve, the study of stages like diplotene will undoubtedly contribute to advancements in genetics, medicine, and our overall understanding of life itself.

在遗传学的复杂世界中，理解减数分裂的各个阶段对于掌握生物体如何繁殖和传递其遗传物质至关重要。一个鲜为人知但重要的减数分裂阶段被称为diplotene。这个术语指的是减数分裂前期I中的一个特定阶段，在这个阶段，同源染色体开始分离。在这篇文章中，我们将探讨diplotene在遗传多样性和繁殖中的重要性。在减数分裂过程中，一个二倍体细胞经历两轮分裂，以产生四个单倍体细胞。第一轮称为减数分裂I，由几个阶段组成：前期、配对期、粗线期、diplotene、分离期，最后是中期I。这些阶段中的每一个都在确保遗传物质的准确分配和重组中发挥着关键作用。具体而言，diplotene的特征是同源染色体逐渐分离，这些染色体是包含相同基因但可能具有不同等位基因的成对染色体。diplotene的重要性在于它在交叉互换过程中的作用，该过程发生在前一阶段的粗线期。在交叉互换过程中，DNA片段在同源染色体之间进行交换，从而导致遗传重组。这个过程对于增加种群内的遗传多样性至关重要。当diplotene发生时，染色体仍然在交叉点（即交叉互换发生的地方）上保持连接。这使得遗传物质的交换成为可能，同时也确保了染色体在准备分离时的正确对齐。此外，diplotene不仅对遗传多样性重要，还对染色体的正确分离至关重要。如果在这个阶段发生错误，可能会导致非整倍体，即细胞具有异常数量的染色体。非整倍体可能导致各种遗传疾病，例如唐氏综合症，这种疾病是由于存在额外的21号染色体拷贝所致。因此，理解diplotene及其影响对于基础生物学和医学研究都是至关重要的。在许多物种中，包括人类，diplotene可能持续很长时间，有时甚至达到数年。例如，在人类女性中，卵母细胞可以在diplotene中停留数十年，直到排卵发生。这种延长的暂停突显了生殖生物学的复杂性以及减数分裂过程的精细调控。它还引发了有关影响减数分裂时机的因素以及环境条件如何影响生育能力的有趣问题。总之，减数分裂中的diplotene阶段是一个关键的转折点，它促进遗传多样性并确保在细胞分裂过程中染色体的准确分配。通过理解这一阶段，科学家可以深入了解繁殖机制以及遗传疾病的潜在原因。随着研究的不断发展，对像diplotene这样的阶段的研究无疑将有助于遗传学、医学以及我们对生命本身的整体理解的进步。