The Evolution of New Organs Usually Builds on Preexisting Structures

question 21

Multiple Choice

The evolution of new organs usually builds on preexisting structures that are modified in form and sometimes function.The embryos of fish,amphibians,reptiles,birds,and mammals all have pharyngeal pouches or gill slits.These pouches develop into gills in adult fish and they are used to absorb oxygen from their watery environment.These same pouches become parts of the ________ in humans.

• A) lungs and heart
• B) eyes and nose
• C) ear and throat
• D) eyes and lungs

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Definitions:

Chondrosarcoma

is a type of cancer that occurs in the cartilage cells of the body, typically affecting the pelvis, legs, or arms.

Cartilage Cells

Also known as chondrocytes, these are the cells found in cartilage tissue.

Xerostomia

A condition characterized by dry mouth resulting from reduced or absent saliva flow.

Fungating

Refers to a type of tumor that grows rapidly and projects from the skin or any mucosal surface, often ulcerating.