Animal Groups
Scientists have classified animals into various groups, including:
1. Mammals:
- Characteristics:
- Reproduce by giving birth and nursing their young.
- Covered with hair or fur.
- Breathe through lungs.
- Examples: Cow, horse, lion, camel, monkeys, elephants, dolphins, bats. Bats, despite resembling birds due to having wings, are classified as mammals.
2. Reptiles:
- Characteristics:
- Reproduce by laying eggs.
- Dry skin covered with scales.
- Breathe through lungs.
- Examples: Snakes, crocodiles, turtles.
3. Insects:
- The most widespread group of animals on Earth.
- Characteristics:
- Reproduce by laying eggs.
- Have six legs.
- Possess sensory antennae (located on the front of their heads for smelling and detecting sounds).
- Have bodies covered with a hard exoskeleton.
- Examples: Grasshoppers, bees, ants, cockroaches.
4. Birds:
- Characteristics:
- Reproduce by laying eggs.
- Covered with feathers.
- Possess two legs, a beak, and most have wings.
- Breathe through lungs.
- Examples: Chicken, sparrow, penguin.
5. Fish:
- Characteristics:
- Reproduce by laying eggs.
- Bodies covered in scales.
- Live in water.
- Have fins for movement.
- Breathe through gills.
- Examples: Carp, shark.
6. Amphibians:
- Characteristics:
- Reproduce by laying eggs, which are laid in water.
- Have moist skin.
- Begin their lives in water, breathe through gills, and when they mature, live near water on land and breathe through lungs.
- Examples: Frog, salamander, sea turtle.
Amphibians have two life stages:
-
- Larval stage in water, where they breathe through gills like fish.
- Adult stage on land, where they breathe through lungs.
The main animal groups can be further classified into smaller groups.
Whales are classified as mammals because they reproduce by giving birth, even though they live in water.
Bats are classified as mammals because they reproduce by giving birth, despite their ability to fly like birds.