Biology Slide 1 of 50 Copyright Pearson Prentice

Biology Slide 1 of 50 Copyright Pearson Prentice Hall End Show

32 -1 Introduction to the Mammals Slide 2 of 50 Copyright Pearson Prentice Hall End Show

32 -1 Introduction to the Mammals All mammals have two notable features: hair and mammary glands. In females, mammary glands produce milk to nourish the young. Slide 3 of 50 Copyright Pearson Prentice Hall End Show

32 -1 Introduction to the Mammals In addition to having hair and the ability to nourish their young with milk, all mammals • breathe air. • have four-chambered hearts. • are endotherms that generate their body heat internally. Slide 4 of 50 Copyright Pearson Prentice Hall End Show

32 -1 Introduction to the Mammals Evolution of Mammals The first true mammals appeared during the late Triassic Period, about 220 million years ago. These mammals were very small and probably nocturnal. Slide 5 of 50 Copyright Pearson Prentice Hall End Show

32 -1 Introduction to the Mammals Reptile / Mammal Skulls Slide 6 of 50 Copyright Pearson Prentice Hall End Show

32 -1 Introduction to the Mammals Form and Function in Mammals As mammals evolved, the form and function of their jaws and teeth became adapted to eat foods other than insects. The joint between the skull and lower jaw allowed mammals to evolve larger, more powerful jaw muscles and different ways of chewing. Slide 7 of 50 Copyright Pearson Prentice Hall End Show

32 -1 Introduction to the Mammals Form and Function in Mammals Jaws and Teeth of Mammals Carnivore Herbivore Canines Jaw joint Wolf Incisors Molars and premolars Copyright Pearson Prentice Hall Jaw joint Horse Slide 8 of 50 End Show

32 -1 Introduction to the Mammals Form and Function in Mammals Mammalian heart Left atrium Right atrium Left ventricle Right ventricle Complete division Copyright Pearson Prentice Hall Slide 9 of 50 End Show

32 -1 Introduction to the Mammals Form and Function in Mammals Mammalian Brain Slide 10 of 50 Copyright Pearson Prentice Hall End Show

32 -1 Introduction to the Mammals Form and Function in Mammals The limbs and digits (fingers and toes) of many mammals are adapted to their particular way of life. Note the variety of lengths and shapes of the limb bones. Homologous bones are the same color in all the drawings. Monkey Horse Mole Bat Seal Slide 11 of 50 Copyright Pearson Prentice Hall End Show

32 -1 Click to Launch: Continue to: - or - Slide 12 of 50 End Show Copyright Pearson Prentice Hall

32 -1 One characteristic commonly used to determine whether fossils are mammals is a. subcutaneous fat. b. mammary glands. c. a jaw joint that allows movement from side to side. d. hair or fur. Slide 13 of 50 End Show Copyright Pearson Prentice Hall

32 -1 How many chambers do mammalian hearts have? a. 2 b. 3 c. 4 d. 6 Slide 14 of 50 End Show Copyright Pearson Prentice Hall

32 -1 Mammals are called endotherms because they a. produce milk to nourish their young. b. have well-developed sense organs. c. have powerful jaws and specialized teeth. d. generate their body heat internally. Slide 15 of 50 End Show Copyright Pearson Prentice Hall

32 -1 The first true mammals appeared in the fossil record a. soon after the extinction of the dinosaurs. b. about the same time as the first reptiles. c. during the Triassic when dinosaurs were the dominant land animals. d. long after the extinction of the dinosaurs. Slide 16 of 50 End Show Copyright Pearson Prentice Hall

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