Hair and Mammary Glands Chapter 30 Mammals 30.1 Mammalian Characteristics Hair and Mammary Glands Two characteristics that distinguish members of class Mammalia from other vertebrate animals are hair and mammary glands. Mammary glands: produce and secrete milk for young
Sensory devices (whiskers) Chapter 30 Mammals 30.1 Mammalian Characteristics Functions of Hair Insulation Camouflage Sensory devices (whiskers) Waterproofing Signaling (tail color) Defense (quills)
Other Characteristics Chapter 30 Mammals 30.1 Mammalian Characteristics Other Characteristics Endothermic Source of body heat is internal. Heat is produced by a high metabolic rate.
30.1 Mammalian Characteristics Chapter 30 Mammals 30.1 Mammalian Characteristics
Mammals are divided into 4 trophic categories depending on diet: 1. Insectivores: feed on insects 2. Herbivores: feed on vegetation
3. Carnivores: feed on herbivores 4. Omnivores: feed on plants and animals
Carnivores use canines to stab and premolars to slice and shear meat Chapter 30 Mammals 30.1 Mammalian Characteristics Teeth Carnivores use canines to stab and premolars to slice and shear meat
Incisors of insectivores are long and curved, functioning as pincers
Teeth location
Excretory System
Excretion Liver transforms nitrogenous waste into urea Chapter 30 Mammals 30.1 Mammalian Characteristics Excretion Liver transforms nitrogenous waste into urea Kidneys filter urea from blood and combine it with other waste to form urine
Kidneys excrete or retain the proper amount of water in body fluids Enables mammals to live in extreme environments
Respiratory System
Mammals are the only animals that have a diaphragm. Chapter 30 Mammals 30.1 Mammalian Characteristics Respiration Well developed lungs High levels of oxygen are required to maintain a high level of metabolism. Mammals are the only animals that have a diaphragm.
Diaphragm: sheet of muscle found below the lungs that allows the chest cavity to enlarge
Circulatory System
Double looped, closed circulatory system 4 chambered heart Double looped, closed circulatory system One loop: blood travels between heart and lungs Second loop: blood travels from heart to the rest of the body
30.1 Mammalian Characteristics Chapter 30 Mammals 30.1 Mammalian Characteristics Circulation Keeping oxygenated and deoxygenated blood separate makes the delivery of nutrients and oxygen more efficient.
Nervous System
30.1 Mammalian Characteristics Chapter 30 Mammals 30.1 Mammalian Characteristics The Brain and Senses Highly developed brains. Cerebral cortex is responsible for coordinating conscious activities, memory, and the ability to learn. Cerebellum is responsible for balance and coordinating movement.
Most mammals see in black and white Strong sense of smell, taste, and hearing
Chapter 30 Mammals 30.1 Mammalian Characteristics Glands Glands: secretes a variety of fluids that helps to regulate a mammal’s internal environment. Ex. Sweat glands
Movement Mammals must find food, shelter, and escape from predators.
In mammals, the egg is fertilized internally. Chapter 30 Mammals 30.1 Mammalian Characteristics Reproduction In mammals, the egg is fertilized internally. Development of the embryo takes place in the female uterus.
Mammal Classification (based on reproduction) Chapter 30 Mammals 30.2 Diversity of Mammals Mammal Classification (based on reproduction) Monotremes Marsupials Placental mammals
Reproduce by laying leathery eggs Chapter 30 Mammals 30.2 Diversity of Mammals Monotremes Similar to reptiles Reproduce by laying leathery eggs Have a cloaca Echidna
Examples of Monotremes Echidna Duck billed platypus
Live birth but very early stage Chapter 30 Mammals 30.2 Diversity of Mammals Marsupials Live birth but very early stage Crawl into a pouch made of skin and hair and continue development Ex. Kangaroo, opossum, koala Kangaroo
Chapter 30 Mammals 30.2 Diversity of Mammals Placental Mammals Give birth to live young that do not need further development within a pouch Shrew Humpback whale
Placenta: structure that provides oxygen and nutrition, removes waste