1. The pronephros is a primitive kidney structure found in some lower vertebrates.
肾前体是一种存在于一些低等脊椎动物中的原始肾脏结构。

2. The pronephros functions to filter waste products from the blood and excrete them as urine.
肾前体的功能是过滤血液中的废物并将其排泄为尿液。

3. In early embryonic development, the pronephros is the first functional kidney structure to form.
在早期胚胎发育中，肾前体是第一个形成的功能性肾脏结构。

4. The pronephros eventually degenerates and is replaced by the more advanced mesonephros in higher vertebrates.
肾前体最终会退化，并在更高等脊椎动物中被更先进的中肾替代。

5. Evolutionarily, the pronephros is considered a primitive kidney structure that has been modified and improved upon in more complex organisms.
从进化的角度来看，肾前体被认为是一种原始的肾脏结构，在更复杂的生物体中经过了改造和改进。

6. Abnormalities in the development of the pronephros can lead to kidney malformations and dysfunction in the affected organism.
肾前体发育异常可能导致受影响生物体的肾脏畸形和功能障碍。