Unit 8 Vertebrates: Amphibians and Reptiles, New Castelar College

NEW CASTELAR COLLEGE International School Biology S1

Unit 8 - Vertebrates

• L1. Vertebrates: Fish

Lesson 2 - Amphibians and Reptiles

• L3. Birds and Mammals

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List of terms Lesson 2

Biology S1

• Amphibians
• Ectotherms
• Reproduction
• Oviparous
• Ovoviviparous
• Lizards
• Metamorphosis
• Turtles
• Anura
• Bony Shell
• Snakes
• Venom
• Crocodiles
• Carnivores
• Salamanders
• Herbivores
• Newts
• Omnivores
• Reptiles
• Waterproof skin
• Scales
• Gills
• Horny beak
• Double circulatory system
• Molting / Shedding
• Pulmocutaneous circuit
• Pulmonary circuit
• Systemic circuit
• Kidneys
• Urine
• Eyelids
• Sense of smell
• Vocal cords
• Eyesight
• Loreal pits
• Internal fertilisation
• Moist skin
• Limbs
• External fertilisation
• Membranes
• Toxic glands
• Adults
• Frog
• Toad
• Tadpoles
• Nutrition
• Urodela
• Lungs
• Skin

7

• Sensitivity
• Croak

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Learning objetives: Amphibians

Biology S1

• To know the main characteristics and the life processes of amphibians.

1. Amphibians can live in water and on land because they have moist skin for breathing and go through metamorphosis to develop lungs and limbs.

Amphibians VS Reptiles

1. Reptiles regulate their body temperature by using the sun to warm up and shade or cool surfaces to cool down.

DO IT NOW !

1. What adaptations help amphibians survive both in water and on land?
2. How do reptiles regulate their body temperature without the ability to produce their own heat?

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Amphibians Biology S1

• Amphibians spend the first stages of their life in the water. As adults, most live in terrestrial environments.
• Like fish, they are ectotherms.
• They cannot live in dry environments. They have bare moist skin.

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Amphibians Characteristics

Biology S1

• They have four limbs, which are legs with membranes between the toes to help them swim.
• Some have a tail.
• They have a large mouth with teeth and a long sticky tongue.
• Some have toxic glands on their skin.

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Amphibians Nutrition

Biology S1

1. NUTRITION

• Adults are carnivores, but tadpoles are herbivores or omnivores.
• Adults breathe through lungs and their skin, but tadpoles breathe through gills.

O2 CO2

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Amphibians Circulatory System

Biology S1

1. NUTRITION

• £ They have a double circulatory system, which means two circuits. The first one carries the blood from the heart to the lungs, and the second from the heart to the body.

Amphibians Lung and Skin Capillaries

Pulmocutaneous circuit Atrium (A) Ventricle (V) Atrium (A) Left Right Systemic circuit Systemic capillaries

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Amphibians Sensitivity

Biology S1

1. SENSITIVITY

• They have eyes with three eyelids.
• They have vocal cords to make sounds.
• In the breeding season, male frogs and toads croak to attract females.

a b C d

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Amphibians Reproduction

Biology S1

1. REPRODUCTION

• Most are oviparous and fertilization is external.
• When the eggs hatch, the tadpoles go through metamorphosis and change into the adult form.

The Life Cycle Of A Frog

Eggs Embryo Tadpole Frog Tadpole with 4 legs Tadpole with 2 legs

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Amphibians - Classification

Biology S1

1. Anura

• They include frogs and toads.
• They don't have a tail.
• Their back legs are long and adapted for jumping.

Frog Toad

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Amphibians - Urodela Classification

Biology S1

1. Urodela

• They include salamanders and newts.
• They have a tail and long body.
• Their legs are all the same size.

Salamander Newt Chinese giant salamander

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Review Questions Biology S1

Fill in the blanks with the correct words: skin, lungs, water, metamorphosis, cold- blooded

1. Amphibians are animals, which means they rely on the environment to control their body temperature.
2. They can live both in and on land.
3. Young amphibians breathe through gills, but adults use to breathe air.
4. Amphibians also absorb oxygen through their moist .
5. The change from a tadpole to an adult frog is called .

1. cold-blooded 2. water 3. lungs 4. skin 5. metamorphosis

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Reptiles Biology S1

• Most are terrestrial, but some like sea turtles are aquatic.
• Like fish and amphibians, they are ectotherms.
• They have a waterproof skin covered with scales, that allows them to live in very dry environments.

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Reptiles Physical Characteristics

Biology S1

• Reptiles have a long pointed tail.
• Most have four short legs, but some don't have legs.
• They move by slithering or crawling.
• Some have large teeth, while others have a horny beak.
• Snakes and lizards molt and shed their skin to grow.

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Reptiles Nutrition and Circulation

Biology S1

1. NUTRITION

• reptiles are carnivores and swallow their prey whole.
• They breathe through lungs and have a double circulatory system.
• Their kidneys produce urine with very little water.

Pulmonary circuit Lung capillaries Right systemic aorta Left systemic aorta A --- A V V Incomplete septum Right Left Systemic capillaries Systemic circuit

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Reptiles Sensitivity and Loreal Pits

Biology S1

1. SENSITIVITY

• They have a highly developed sense of smell and eyesight.
• Snakes also have organs called loreal pits, which detect changes in temperature.

brain Jacobson's organ nostril tongue sheath Loreal pit Nostril

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Reptiles Reproduction

Biology S1

1. REPRODUCTION

• Fertilization is internal.
• They are oviparous or ovoviviparous.
• Reptile eggs have a covering, which prevents them from losing water.
• They lay eggs on land and don't usually care for their young.

Shell Albumen Amniotic cavity (filled with amniotic fluid) Yolk Amnion Embryo Allantois Yolk sac Chorion Cloaca

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Reptiles Reproduction Details

Biology S1

1. REPRODUCTION

• Fertilization is internal.
• They are oviparous or ovoviviparous.
• Reptile eggs have a covering, which prevents them from losing water.
• They lay eggs on land and don't usually care for their young.

Shell Albumen Amniotic cavity (filled with amniotic fluid) Yolk Amnion Embryo Allantois Yolk sac Chorion Cloaca

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Reptiles - Lizards Classification

Biology S1

Gecko

1. Lizards

• They include lizards, geckos, iguanas and chameleons.
• Many shed their tails to escape their predators.

Lizard Komodo dragon Iguana Chameleon

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Reptiles - Turtles Classification

Biology S1

1. Turtles

• They can be terrestrial or aquatic.
• Their body is covered in a bony shell.
• They have a horny beak.

Sea turtle Leatherback sea turtle Spur-thighed tortoise Galapagos tortoise

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Reptiles - Snakes Classification

Biology S1

1. Snakes

• There are many types, like boas, pythons, cobras and vipers.
• They don't have limbs.
• Some are extremely venomous.

Blue viper Coral snake Python Cobra

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Reptiles - Crocodiles Classification

Biology S1

1. Crocodiles

• They have a long snout with many teeth.
• They have a long and strong tail.

Alligator Crocodile Gharial

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Review Questions on Reptiles

Biology S1

Answer if True or False:

1. Reptiles are warm-blooded animals.

1.False 2.False

1. All reptiles lay eggs.
2. True
3. True
4. True
5. Reptiles have dry, scaly skin.
6. Snakes are reptiles.
7. Reptiles breathe through lungs.