The document classifies animals into two main groups: vertebrates and invertebrates. Vertebrates, which make up a small portion, have backbones and are further divided into five classes - fishes, amphibians, reptiles, birds, and mammals. Each class has distinguishing characteristics, such as fishes having scales and gills, amphibians living partly on land and in water, and mammals having hair and mammary glands. Invertebrates, which comprise 90% of species, lack backbones.
3. TWO BIG GROUPS OF ANIMALS
Animals are classified into two big groups
based on similarities in their structure.
The group of animals without backbones
dominates the world. These are called
invertebrates. They make up 90% of all
animal species.
A small portion of the millions of animals
comprise the vertebrate group, those with
backbones.
4.
5. VERTEBRATES
They are further divided into five main
classes. These are:
1. Fishes
2. Amphibians
3. Reptiles
4. Birds
5. Mammals
6. INVERTEBRATES
This big group of invertebrates
is composed of:
Sponges
Coelenterates
Flatworms
Roundworms
Segmented worms
Echinoderms
Mollusks
and the Arthropods.
7. VERTEBRATES ALSO HAVE DIFFERENCES.
The fishes, amphibians, and reptiles are
ectotherms. They are cold-blooded. Their
body temperatures depend on the
temperature of their surroundings. Their
bodies receive heat from the outside.
Birds and mammals are endotherms,
animals with constant internal body
temperatures. They are
warm-blooded animals.
8. VERTEBRATES:
CHARACTERISTICS OF FISHES
They are ectothermic animals. Their
temperature changes when the temperature
of the air or water around them changes.
The bodies are slender enabling the fish to
move easily through water.
Fish have fins used for swimming and
gliding. Fins help them swim, turn, and stop.
9. VERTEBRATES:
FISHES
Hard scales cover their bodies. Fishes have
lateral lines on each side of their bodies
which serve as sensors. Fishes use them to
feel vibrations from the outside environment,
like boats, people, animals, and other things
that may be in the water.
Fishes also have gills for breathing. They
are located on either side of a fish’s head.
10. VERTEBRATES:
AMPHIBIANS
They are cold-blooded.
They spend part of their lives in
water and part on land.
They have slimy and cool skin.
They are four-legged vertebrates.
They depend on water for reproduction.
Their eggs have no shells. They lay eggs in a
pond, swamp, or stream to avoid drying.
Examples are frogs, toads,
salamanders and newts.
11. VERTEBRATES:
REPTILES
They are ectothermic vertebrates.
They have dry, waterproof bodies covered with
scales.
Reptiles produce eggs that have a tough
leathery shell. Fertilization takes place inside
the reptile’s body.
They have a three-chambered heart like the
amphibians.
Examples of reptiles are lizards,
snakes, turtles, tortoises, alligators
and crocodiles.
12. VERTEBRATES:
BIRDS
They have feathers.
They have beaks instead of teeth.
They have wings, though not all can fly.
They have scales on their legs.
The bodies of birds are streamlined to facilitate
flight. They have lightweight bones.
Most birds build nests on branches of trees, in a
hole, or in a trunk or in a small hole in the
ground.
Birds lay eggs with hard shells. Most birds sit
on their eggs until they are hatched.
13. VERTEBRATES:
MAMMALS
They are the most complex of all vertebrates.
They have four-chambered heart.
Distinct to them is the presence of hair and mammary
glands. The mammary glands, which produce milk to
feed their young, are active only in females.
They have more developed brains than any other
animals. Humans, however, have the most developed
brains which is why they are referred to as the “thinking
animal”.
They are warm-blooded. They maintain a
constant body temperature.
14. VERTEBRATES:
MAMMALS
Hair or fur keeps the body warm
by preventing loss of heat. In
the absence of hair on mammals, a layer of
fat under the skin keeps the body heat.
They have limbs, which are adapted for
varied movements such as running,
swimming, climbing, flying or gliding and
hopping.
Examples of mammals are: horses, cows,
dogs, cats, lions, tigers, kangaroo.
