Amphibians and Mammals
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Transcript of Amphibians and Mammals
Amphibians and Mammals
Objective 4.01 & 4.02: Analyze the classification of organisms & processes by which organisms accomplish essential life
functions.
What does the word “Amphibian” mean?• The word Amphibian means “dual life”.• Amphibians spend the first part of their life in
the water and the second part of their life on land.
General Characteristics of Amphibians Amphibians have the following general
characteristics:• Lay eggs in water• Ectotherms (Cold blooded)• Have 4 limbs• Skin is moist and covered with mucus.
Amphibian Circulatory System
• Closed circulatory system• 3 chambered heart
Amphibian Digestive System• Complete digestive system– Two openings : Mouth and anus– Food moves in one direction: Mouth Anus
Amphibian Respiratory System• Gills as tadpoles• Lungs as adults• Skin must be moist for gas exchange (O2 and CO2)
Amphibian Nervous System
• Have a brain, spinal cord and nerves
Amphibian Reproductive System• Sexual reproduction• External fertilization– Female lays eggs, male
releases sperm• Undergo metamorphosis• Must occur in water
Amphibian Examples
Mammals
General Characteristics of Mammals
• Body covered with hair or fur• Produce milk for young in mammary gland
Mammalian Circulatory System• Closed circulatory system• 4 chambered heart = no mixing of blood
Mammalian Digestive System• Complete digestive system– Two openings : Mouth and anus– Food moves in one direction: Mouth Anus
Mammalian Respiratory System• Use lungs
Mammalian Nervous System• Have a brain, spinal cord and nerves
Mammalian Reproductive System
• Internal fertilization• Three groups 1. Placental mammals – young develop in
uterus2. Monotremes – lay eggs3. Marsupials – give birth to live young that
further develops in pouch
Placentals, Monotremes and Marsupials