Diversity in Living Organisms Test - 37

• Snakes and other reptiles are cold-blooded animals. They lack the ability to generate body heat internally. Their body temperature varies with that of the environment.
• Cold-blooded animals are also called poikilotherms.
•  Warm-blooded animals include birds and mammals. These animals regulate their body temperature through mechanisms known as endothermy and homeothermy and hence, are also called endotherms and homeotherms.
• Endothermy refers to the process by which various animals control their body temperature through internal means like burning fat, shivering, and panting.
• Homeothermy is the mechanism utilized by various animals to maintain a constant internal temperature instead of varying external temperatures.
• Most warm-blooded animals use a combination of these two mechanisms to maintain constant body temperature.

So, the correct answer is option D.

• Mammals are characterized by a well-developed diaphragm that separates the thoracic chamber from the abdominal cavity. 
• The diaphragm plays an important role in breathing in mammals. 
• Crocodiles also have a well-developed diaphragm. The lung cavity of the crocodile is separated from the rest of the body cavity by a muscular diaphragm.
• Hence, option 'A' is correct.

• Aves and mammals are warm-blooded animals as they can regulate their body temperature. Hence, options A, B and C fall under the warm-blooded animal category. 
• While snakes are reptiles and all reptiles are cold-blooded animals. They raise their body temperatures by lying in the sun or lower it by crawling. 

• A tortoise/testudo shell is made of two parts the Plastron and Carapace. 
• The upper portion is called the Carapace and the bottom half is called the Plastron. 
• The carapace is the fusion of about 50 bones the ribs and vertebrae.  A bony bridge joins the carapace and the Plastron along the side of the turtle.
• Hence, The option 'D' is correct