Question

В чем отличие скелета высших и нисших хордовых

Answer 1

Низшие хордовые животные: оболочники, бесчерепные.
Высшие хордовые – позвоночные животные.

У низших хордовых животных (тип Бесчерепные) хорда выполняет функции скелета в течении всей жизни, а у. высших она существует только в зародышевом развитии, а у взрослых. замещается позвоночником.

Answer 2

Difference between the Skeletons of Higher and Lower Chordates

The skeletons of higher and lower chordates differ in several ways. Here are some key differences:

1. Composition: The skeletons of higher chordates, such as mammals, birds, and reptiles, are primarily composed of bone. In contrast, the skeletons of lower chordates, such as fish and amphibians, are composed of cartilage or a combination of cartilage and bone.

2. Development: Higher chordates have an endoskeleton that develops from mesodermal cells. This endoskeleton includes a vertebral column, which provides support and protection for the spinal cord. Lower chordates, on the other hand, may have a notochord, which is a flexible rod-like structure that provides support, but it is eventually replaced by the vertebral column in higher chordates.

3. Complexity: The skeletons of higher chordates tend to be more complex and specialized compared to those of lower chordates. Higher chordates have a well-developed skull, limbs, and other specialized structures that allow for more diverse movements and adaptations. Lower chordates, such as fish, may have simpler skeletons that are adapted for swimming.

4. Mineralization: The skeletons of higher chordates are typically more heavily mineralized compared to those of lower chordates. This mineralization provides increased strength and rigidity to support the larger body size and more complex movements of higher chordates.

5. Evolutionary History: The skeletons of higher chordates have evolved from the simpler skeletons of their lower chordate ancestors. Over time, the development of bone and the evolution of specialized structures have allowed higher chordates to adapt to various environments and lifestyles.

It's important to note that these differences are generalizations and there can be variations within each group of chordates. Additionally, the classification of organisms into higher and lower chordates is based on evolutionary relationships and does not necessarily imply superiority or inferiority.

I hope this information helps! Let me know if you have any further questions.