Vertebrates and Invertebrates | Year 3 Science PDF Download

Vertebrates

• Vertebrates are animals that have a spine (backbone) inside their body. 
• Having a backbone categorizes animals as vertebrates. 
• In contrast, creatures like spiders and snails, lacking a backbone, fall under the category of invertebrates.

Main Groups of Vertebrates

• Mammals: Lions, humans, and dolphins are examples of mammals. They breathe through their lungs, are warm-blooded, give birth to live babies, and possess hair or fur.
  
• Birds: Penguins and golden eagles are examples of birds. They breathe through their lungs, are warm-blooded, lay eggs with hard shells, and have feathers and wings.
  
• Reptiles: Lizards, snakes, and crocodiles fall under this category. They breathe through their lungs, are cold-blooded, lay eggs with soft shells, and possess dry scales.
  
• Amphibians: Amphibians like frogs, toads, and newts are born with gills which later develop into lungs. They are cold-blooded and lay eggs in water.
  
• Fish: Sharks and salmon fall under this category. Fish breathe through gills, lay eggs in water, and are cold-blooded.

Understanding Differences and Similarities in Animals

Animals can vary greatly in appearance and behavior.

• Some live on land, others can fly, and some reside in water.
• Some animals eat plants, while others hunt other animals for food. Some are large, while others are much smaller.

Despite these differences, they all have a spine, making them vertebrates, just like you!

What are invertebrates?

• Invertebrates are animals that can be found across the world in various habitats. 
• They do not have a backbone or spine inside their bodies.

Key facts about invertebrates

• Invertebrates are animals without a spine or backbone inside their body.
• Minibeasts like woodlice and centipedes are small invertebrates, but not all invertebrates are small. For example, the giant squid can grow over ten meters long!
• Animals like you, which have a backbone, are called vertebrates.
• Some invertebrates, such as snails, protect themselves with shells. Others have a hard outer layer called an exoskeleton. The prefix "exo-" means outside, so an exoskeleton is an "outside skeleton." Ants, woodlice, and spiders all have exoskeletons for protection.

Invertebrates are divided into five main groups

Invertebrates are classified into five main groups in the animal kingdom, each with unique characteristics and examples:

• Insects: Beetles, ants, and flies belong to this group. They all possess six legs and three body parts. For instance, beetles showcase a hard exoskeleton and forewings that form protective covers over their hind wings.
  
• Crustaceans: Shrimps, crabs, and lobsters are examples of crustaceans, primarily dwelling in aquatic environments. These creatures typically have segmented bodies and appendages like pincers for feeding and defense.
  
• Arachnids: Spiders and scorpions are part of the arachnid category, characterized by eight legs and two body segments. For example, spiders use silk to spin webs for trapping prey or creating shelters.
  
• Snails and Slugs: Both snails and slugs exhibit a 'foot' structure for movement. They are commonly found in damp habitats, utilizing mucus to glide over surfaces.
  
• Worms: Worms are known for their presence in soil environments. They play crucial roles in aerating soil and decomposing organic matter, contributing to ecosystem health.