Evolutionary Pressures in Mammals
EVOLUTIONARY PRESSURES IN MAMMALS Mammals are naturally distributed on all continents except Antarctica. They live in all oceans. EXTERNAL STRUCTURE AND LOCOMOTION SKIN The skin of a mammal consists of…
EVOLUTIONARY PRESSURES IN MAMMALS Mammals are naturally distributed on all continents except Antarctica. They live in all oceans. EXTERNAL STRUCTURE AND LOCOMOTION SKIN The skin of a mammal consists of…
CLASSIFICATION OF MAMMALS Class Mammalia Mammary glands: hair: diaphragm: three middle-car ossicles; heterodont dentition;sweat, sebaceous and scent glands: four- chambered heart; large cerebral cortex. (a) Subclass Prototheria This subclass formerly…
DIVERSITY OF MAMMALS Modern mammals have following characteristics: 1. They have hair on the body. 2. They have mammary glands. 3. They have specialized teeth. They have heterodont dentition 4.…
MAMMALS EVOLUTIONARY PERSPECTIVE Tertiary period started about 70 million years ago. It was the start of the "age of mammals." It produces adaptive radiation in the mammals. Extinction of many…
OBJECTIVES OF BIRDS Multiple Choice Questions MCQs 1. The age of reptiles is: (a) Jurassic period (b) Tertiary period (c) Secondary period (d) Triassic period 2. Early synapsids were: (a)…
SUBJECTIVE QUESTIONS IN BIRDS Why are birds called as "glorified reptiles"? Or Discuss phylogenetic relationships of birds. Discuss evolution of flight. What is the evolutionary significance of Archaeopteryx? Write note…
DEFINITIONS AND KEY POINTS FOR OBJECTIVES IN BIRDS TERMS DEFINITIONS Plumage The covering of leathers on a bird is called the plumage. Preening Preening keeps the feathers smooth, clean and…
EVOLUTIONARY PRESSURES IN BIRDS Every body system of a bird shows some adaptation for flight. These adaptations are endothermy, feathers, acute senses, long, flexible necks and lightweight hones. EXTERNAL STRUCTURE…
CLASSIFICATION IN BIRDS Class Aves Adaptation for flight include: forelimbs are modified as feathered wings, endothermic, high metabolic rate, flexible neck, fused posterior vertebrae, and bones lightened by numerous air…
THE BIRDS FEATHER FLIGHT & ENDOTHERMY EVOLUTIONARY PROSPECTIVE PHYLOGENETIC RELATIONSHIPS Birds are traditionally classified as class Aves. Birds have adaptations for flight. The major characteristics of this class are: 1.…