Chapter 29.1, Problem 5MI

Summary Introduction

To identify:

The adaptations that made reptiles to survive on land.

Introduction:

Reptiles are cold-blooded tetrapods. Even aquatic reptiles lay their eggs on land. Reptiles have scaly skin that contains keratin proteins and lungs to breath. These features made reptiles to live on land.

Explanation of Solution

The adaptations that made reptiles to survive on land are given in the table below:

Needed for Life on Land	Adaptation
Protect embryo from drying out	Amnion membrane of the amniotic egg keeps the embryo from drying out.
Prevent the excessive loss of water and minerals from the body	Dry, scaly skin with keratin prevents water loss. The cloaca reabsorbs water from urine before excretion.
Exchange gases other than through the skin	Lungs with larger surface area and ability to inhale and exhale through muscular contraction.
Crocodile’s need for more oxygen delivered to cells to help move its large body	Almost all the reptiles have a three-chambered heart. But the four-chambered heart of crocodile supplies more oxygen
Snake’s need to swallow prey larger than itself	Loosely joined bones of the skull and jaw that can spread apart.
Complex vision and muscle function	Larger optic lobes and cerebellum provide complex vision.
Move faster and bear more body weight	Limbs rotated farther under the body; claws on toes enable them to move fast.