Final answer:
The correct associations are: Endoderm forms the digestive and respiratory systems, Mesoderm forms the musculoskeletal and circulatory systems, and Ectoderm forms the skin and nervous system.
Step-by-step explanation:
The Primary Germ Layers and their Associated Organs
The primary germ layers, which are vital during embryonic development, consist of the ectoderm, mesoderm, and endoderm.
These layers develop into specific tissues and organs within the body. Let's look at what each germ layer gives rise to:
- Ectoderm: This outermost layer develops into the nervous system, including the central and peripheral systems, as well as the epidermis (the outer layer of skin), hair, and nails.
- Mesoderm: Positioned between the ectoderm and endoderm, the mesoderm forms the muscle cells and connective tissues, such as the skeleton, heart, blood vessels, and kidneys.
- Endoderm: The innermost layer gives rise to the epithelial lining of the digestive and respiratory tracts, and it also forms internal organs like the liver and pancreas.
Therefore, the correct association between the germ layers and the organs they form is:
- Endoderm - digestive system and the respiratory system
- Mesoderm - musculoskeletal system and the circulatory system
- Ectoderm - skin and nervous system
Contrary to the options provided, which contain errors:
The endoderm does not lead to the nervous system; it is responsible for the digestive and respiratory systems.
The mesoderm does not give rise to the digestive system, but rather to the musculoskeletal and circulatory systems.
Finally, the ectoderm does not produce the circulatory system; it develops the skin and nervous system.