alecithal egg

简明释义

无黄卵

英英释义

例句

1.The study of the development of the alecithal egg provides insights into early embryonic stages.

对无卵黄卵发育的研究为早期胚胎阶段提供了见解。

2.The alecithal egg is typically found in certain types of mammals and some invertebrates.

无卵黄卵通常在某些类型的哺乳动物和一些无脊椎动物中发现。

3.Understanding the characteristics of the alecithal egg can help in reproductive biology studies.

理解无卵黄卵的特征有助于生殖生物学研究。

4.In some species, the alecithal egg is a key feature that differentiates them from others.

在某些物种中，无卵黄卵是将它们与其他物种区分开来的关键特征。

5.Researchers observed how the alecithal egg develops without the presence of yolk.

研究人员观察了无卵黄卵如何在没有卵黄的情况下发育。

作文

The study of embryology reveals a fascinating diversity in the reproductive strategies of various organisms. One important classification within this field is the type of eggs produced by different species. Among these classifications, the term alecithal egg refers to eggs that contain very little or no yolk. This characteristic has significant implications for the development of the embryo and the overall reproductive strategy of the organism. Understanding alecithal eggs is crucial for students and researchers interested in developmental biology and evolutionary adaptations.In many organisms, the amount of yolk in an egg influences how the embryo develops. For example, in species with large amounts of yolk, such as birds and reptiles, the yolk provides essential nutrients that support the growth of the embryo during its early stages. However, in species that produce alecithal eggs, such as certain mammals, the situation is quite different. These eggs are typically smaller and rely on maternal resources for nourishment rather than yolk reserves.The presence of minimal yolk in alecithal eggs leads to unique developmental processes. In mammals, the embryo often implants into the uterine wall where it can draw nutrients directly from the mother’s bloodstream. This method of development allows for a more complex and prolonged gestation period, which can result in more developed offspring at birth. The evolution of alecithal eggs in mammals is thought to be an adaptation that enables greater parental investment, leading to higher survival rates for the young.In contrast, organisms that produce yolk-rich eggs, such as amphibians and fish, often have a different approach to reproduction. Their embryos develop independently in the egg, utilizing the yolk for sustenance until they are ready to hatch. This strategy can lead to a higher number of offspring being produced at once, but it may also result in lower survival rates due to predation or environmental factors.The concept of alecithal eggs is not only important for understanding mammalian development but also sheds light on broader evolutionary trends. The shift from yolk-dependent to maternal-nourished embryos represents a significant evolutionary milestone. It reflects an adaptation to terrestrial life, where the ability to provide direct nourishment to developing young can enhance their chances of survival in a more complex environment.Furthermore, the study of alecithal eggs has implications for reproductive technologies and conservation efforts. Understanding the unique requirements of these eggs can help scientists develop better practices for breeding endangered species or assist in artificial reproductive techniques. By mimicking the maternal environment that supports alecithal eggs, researchers can improve the success rates of breeding programs for various mammals.In conclusion, the term alecithal egg encapsulates a critical aspect of reproductive biology that highlights the diversity of developmental strategies across species. By examining the characteristics and implications of alecithal eggs, we gain insights into the evolutionary adaptations that have shaped the way different organisms reproduce and care for their young. This understanding not only enriches our knowledge of biology but also informs practical applications in conservation and reproductive science.

胚胎学的研究揭示了不同生物在繁殖策略上的迷人多样性。在这个领域中的一个重要分类是不同物种所产生的卵子的类型。在这些分类中，术语无卵黄卵指的是含有很少或没有卵黄的卵子。这一特征对胚胎的发展和生物的整体繁殖策略具有重要影响。了解无卵黄卵对于对发育生物学和进化适应感兴趣的学生和研究人员至关重要。在许多生物中，卵子中卵黄的数量影响胚胎的发育。例如，在卵黄丰富的物种中，如鸟类和爬行动物，卵黄提供了支持胚胎在早期阶段生长所需的营养。然而，在产生无卵黄卵的物种中，如某些哺乳动物，情况则截然不同。这些卵子通常较小，依赖母体资源而非卵黄储备来提供营养。无卵黄卵中卵黄的缺乏导致了独特的发育过程。在哺乳动物中，胚胎通常会植入子宫壁，从而能够直接从母亲的血液中获取营养。这种发育方式允许更复杂和更长时间的妊娠期，这可以导致出生时后代更加成熟。哺乳动物中无卵黄卵的进化被认为是一种适应，能够增加父母的投资，从而提高幼崽的生存率。相反，产生富含卵黄卵子的生物，如两栖动物和鱼类，往往有不同的繁殖方式。它们的胚胎在卵子中独立发育，利用卵黄作为养分，直到准备孵化。这种策略可以导致一次产生更多的后代，但也可能由于捕食或环境因素而导致较低的生存率。无卵黄卵的概念不仅对理解哺乳动物的发育重要，还揭示了更广泛的进化趋势。从依赖卵黄到母体营养的转变代表了一个重要的进化里程碑。它反映了一种适应陆地生活的能力，即为正在发育的幼崽提供直接营养，可以提高它们在复杂环境中的生存机会。此外，研究无卵黄卵对生殖技术和保护工作也有重要意义。了解这些卵子的独特需求可以帮助科学家制定更好的濒危物种繁殖实践或协助人工生殖技术。通过模拟支持无卵黄卵的母体环境，研究人员可以提高各种哺乳动物繁殖计划的成功率。总之，术语无卵黄卵概括了繁殖生物学的一个关键方面，突显了不同物种间发育策略的多样性。通过考察无卵黄卵的特征及其影响，我们获得了对塑造不同生物繁殖和抚养幼崽方式的进化适应的深入见解。这种理解不仅丰富了我们对生物学的知识，也为保护和生殖科学的实际应用提供了指导。