Chapter 12.3 Notes: AMPHIBIANS
What is an Amphibian?
- An amphibian is a vertebrate that is ectothermic and spends its early life in ______.
- Spend most of their adulthood on land, returning to the water to reproduce.
- Amphibian means double life.
- i.e. frogs, toads, salamanders
Reproduction and Development
- ______= internal fertilization
- Larvae look like adult salamanders
- Metamorphosis to lose gills
- ______= external fertilization
- Fertilized eggs covered in jelly are laid in the water to develop
- Stages of frog/toad lifecycle: egg => tadpole => tadpole with legs => froglet => frog
- Tadpoles have gills and live in water
- Metamorphosis to grow lungs/lose gills and add to circulatory system
Diversity of Amphibians
- 2 majors groups:
- salamanders- have a tail
- frogs/toads- no tail
- difference is the ______
Living on Land
- Respiratory and circulatory systems of adult amphibians are adapted for life on land, i.e. movement, breathing.
Obtaining Oxygen
- Lose ______and grow ______during metamorphosis
- Lungs are sac-like organs of air breathing vertebrates which transfer oxygen from the air into the blood and CO2 from the blood into the air.
- ______also used in O2 and CO2 exchange
Circulatory System
- Tadpoles:
- Single loop heart with 2 chambers (like fish)
- Adult: 2 loops and a heart with 3 chambers
- Atria: Upper chambers of heart, receive blood from lungs/body
- Ventricle: lower chamber of heart, pumps blood to lungs/body
Movement
- Strong skeleton to ______
- Muscular limbs for ______(salamanders), walking and ______(frogs/toads)
- Hopping = strong hind legs and shock absorbing skeleton
Amphibians in Danger!
- Habitat destruction is causing a major decline in amphibian species.
- Mostly deforestation and pollution
- Frogs are very sensitive to environmental change and are therefore used frequently as an ______to determine the health of the entire ecosystem
- Environmental changes due to: pesticides, water pollution, etc.
External Anatomy
Internal Anatomy
·http://www.aa.psu.edu/biology/frog/femaleanat.htm
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·http://frog.edschool.virginia.edu/Frog2/Dissection/Incisions/skin1_first.html
Chapter 12.3 Notes: AMPHIBIANS: TEACHER
What is an Amphibian?
- An amphibian is a vertebrate that is ectothermic and spends its early life in water.
- Spend most of their adulthood on land, returning to the water to reproduce.
- Amphibian means double life.
- i.e. frogs, toads, salamanders
Reproduction and Development
- Salamanders = internal fertilization
- Larvae look like adult salamanders
- Metamorphosis to lose gills
- Frogs = external fertilization
- Fertilized eggs covered in jelly are laid in the water to develop
- Stages of frog/toad lifecycle: egg => tadpole => tadpole with legs => froglet => frog
- Tadpoles have gills and live in water
- Metamorphosis to grow lungs/lose gills and add to circulatory system
Diversity of Amphibians
- 2 majors groups:
- salamanders- have a tail
- frogs/toads- no tail
- difference is the presence of a tail as an adult
Living on Land
- Respiratory and circulatory systems of adult amphibians are adapted for life on land, i.e. movement, breathing.
Obtaining Oxygen
- Lose gills and grow lungs during metamorphosis
- Lungs are sac-like organs of air breathing vertebrates which transfer oxygen from the air into the blood and CO2 from the blood into the air.
- Skin also used in O2 and CO2 exchange
Circulatory System
- Tadpoles:
- Single loop heart with 2 chambers (like fish)
- Adult: 2 loops and a heart with 3 chambers
- Atria: Upper chambers of heart, receive blood from lungs/body
- Ventricle: lower chamber of heart, pumps blood to lungs/body
Movement
- Strong skeleton to support body
- Muscular limbs for crawling (salamanders), walking and hopping (frogs/toads)
- Hopping = strong hind legs and shock absorbing skeleton
Amphibians in Danger
- Habitat destruction is causing a major decline in amphibian species.
- Mostly deforestation and pollution
- Frogs are very sensitive to environmental change and are therefore used frequently as an indicator species to determine the health of the entire ecosystem
- Environmental changes due to: pesticides, water pollution, etc.