"Bivalents"是指在生物细胞中，一对同源染色体在减数分裂过程中彼此配对的现象。这种现象通常发生在减数分裂Ⅰ阶段，特别是在四分体时期。
以下是一篇关于Bivalents的英文范文：
Title: Bivalents in Plant Cell Division
Bivalents are a common phenomenon in plant cell division, occurring during the first meiotic division. During this stage of cell division, pairs of homologous chromosomes from the parent cells pair up, or "bivalents," to prepare for the production of haploid cells.
Bivalents are formed by the pairing of homologous chromosomes, which are copies of chromosomes that were present in the parent cells. These chromosomes share common regions of DNA sequence similarity and can undergo genetic recombination during meiosis. This process allows for the production of new genetic variation, which is essential for plant adaptation and evolution.
Bivalents are also important for proper chromosome segregation during cell division. Chromosomes must be correctly segregated to produce haploid cells with only one set of chromosomes, ensuring that each cell receives an equal amount of genetic material. If chromosomes are not properly paired or segregated, cell division may be disrupted, leading to abnormalities such as aneuploidy or polyploidy.
In summary, bivalents are a crucial aspect of plant cell division that ensures proper chromosome pairing and segregation during meiosis. Understanding bivalents is essential for understanding the genetics and evolution of plants, as well as for developing effective crop breeding strategies.
Bivalents是一个形容词，意思是“成对的；成双的”。
在英文范文中的应用举例如下：
“The chromosomes of humans undergo meiosis, which results in the formation of bivalents during the first division of the cell.”（人类的染色体进行减数分裂，在细胞的第一次分裂过程中，会形成成对的染色体。）
Bivalents是一个名词，意思是“两价染色体”。
在英文范文中的使用，可能会根据上下文和语境有所不同。例如，在描述生物学的某些方面时，可能会提到两价染色体，例如在讨论细胞分裂或基因重组时。
至于Bivalents的最新变化，这个词本身是一个固定的生物学术语，因此其用法和含义在过去几十年中可能没有发生太大变化。然而，随着生物学和相关领域的发展，可能会有新的术语和概念出现，这可能会影响Bivalents的使用。