Which germ layer is primarily responsible for forming the gastrointestinal tract?

• Mesoderm

• Ectoderm

• Endoderm

• None of the above

The lungs develop from which part of the gastrointestinal tract?

• Lower gastrointestinal tract

• Upper gastrointestinal tract

• Middle gastrointestinal tract

• None of the above

What structures are formed by the mesoderm?

• Hair and sweat glands

• Outer layer of skin and nervous system

• Gastrointestinal tract and lungs

• Muscles, bones, and parts of the genitourinary system

Which germ layer contributes to the formation of the heart muscle?

• Ectoderm

• Mesoderm

• None of the above

• Endoderm

Which of the following is NOT formed by the ectoderm?

• Nervous system

• Outer layer of skin

• Hair

• Liver