In a tube-within-a-tube body plan, what is the interior tube derived from? a. ectoderm b. mesoderm c. the coelom d. endoderm

Verified step by step guidance

1. Identify the structure of a tube-within-a-tube body plan. This refers to an organism having an outer tube representing the body wall and an inner tube representing the gut.
2. Understand the germ layers involved in embryonic development: ectoderm, mesoderm, and endoderm.
3. Recognize that the inner tube in the tube-within-a-tube body plan is primarily concerned with the digestive system.
4. Recall that the endoderm is the germ layer that forms the lining of the digestive and respiratory systems.
5. Conclude that the interior tube in a tube-within-a-tube body plan is derived from the endoderm, making the correct answer 'd. endoderm'.

Key Concepts

Germ Layers

During embryonic development, three primary germ layers form: ectoderm, mesoderm, and endoderm. These layers give rise to different tissues and organs in the body. The ectoderm forms the outer layer, the mesoderm develops into muscles and the circulatory system, while the endoderm becomes the innermost layer, contributing to the digestive tract and associated organs.

Coelom

The coelom is a fluid-filled body cavity that lies between the digestive tract and the outer body wall in many animals. It is derived from the mesoderm and provides space for the development of internal organs, allowing them to grow and move independently of the body wall. The presence of a coelom is a key feature in the classification of animals.

Tube-within-a-tube Body Plan

The tube-within-a-tube body plan is a structural organization found in many animals, including humans. It consists of an outer tube (the body wall) and an inner tube (the digestive tract). This arrangement allows for specialization of the digestive system and efficient nutrient absorption, as well as the separation of internal and external environments.