Amphibians and Mammals

Characteristics of Amphibians Vertebrates that includes frogs, toads, salamanders, and newts “Amphibians” means “double life” Amphibians are the ONLY vertebrates that undergo metamorphosis. They have a biophysical life cycle, which means their eggs and larva live in water, but gradually change to be suited to live on land.

Breathes with lungs as an adult Has moist skin with mucus glands Lack scales with claws Cold blooded: meaning they get heat from the environment instead of making it themselves

Life Process of Amphibians Synthesis: Do protein synthesis and build organic molecules Transport: Closed circulatory system with 3 chambered heart and two loops of blood vessels

Excretion: Amphibians have kidneys that filter wastes from their blood. This makes urine which they store in their bladder or pass out through the cloaca. The cloaca is the organ through which waste, urine, and eggs or sperm leaves the body

Respiration: Nutrition: In larvae, gas exchange occurs through the skin and gills. In adults, lungs replace gills, but some gas exchange sill occurs through the skin and mouth. Amphibians take in O2 and release CO2. Nutrition: Hetertrophs that feed on a variety of foods, including plant material and insects

Growth: Reproduction: Undergo metamorphosis to grown form a tadpole (larva) to an adult frog using mitosis Reproduction: Reproduce sexually using external fertilization (Male amphibians squeeze the eggs out of the females and fertilize them as the come out). Eggs are deposited in the water where the larva (tadpoles) will develop until they have eaten their way out of the egg sacs. Tadpoles grow using mitosis until they grow limbs, lose their tails and gills, and develop into terrestrial adults.

Regulation: Communicate using hormones Have a well developed nervous system, including a brain and spinal cord. Amphibians have eyes and ears, which are covered by membranes to keep them moist

Mammals

Characteristics of Mammals Mammals are characterized by: Hair/fur Ability to nourish young with milk (mammary glands) Breathe air 4 chambered heart Endotherms that generate body heat internally

Life Processes of Mammals Synthesis: Do protein synthesis & build organic molecules Transport: Closed circulatory system with a 4 chambered heart and two loops of blood vessels. Blood is efficiently transported, allowing mammals to be very active. Excretion: Have highly developed kidneys that extract wasted form the body and make urine Kidneys are very important in regulating the amount of wastes in the body

Respiration: Nutrition: Growth: Use lungs to take in O2 and release CO2 Nutrition: Mammals are heterotrophs Specialized jaws and teeth that allow them to eat many different types of foods Growth: Mammals have a slow period of development, where they are growing via mitosis

Reproduction: Regulation: Mammals reproduce by internal fertilization. All mammals feed on milk and receive some sort of parental care Regulation: Communicate using hormones Well developed nervous system using the 5 major senses to gather information about the environment: vision, hearing, smell, taste, and touch. Messages are sent electrically (neurons) and chemically (hormones). The brain directs the action of the body

Different groups of mammals have different reproductive methods. Type of Mammal Duck-Billed Platyous Kangaroos, Opossoum Dogs, cats, humans, horses, rodents, rabits, bats, whales, pigs, monkeys, apes Reproductive Methods Monotremes Lay eggs Marsupials Pouch Placental Mammals (90 %) Internal development and live birth