Download UA Ch.2 study guide

Science Unit A: Chapter 2 - Animal Structure and Function study guide
Lesson 1: How are Animals Alike and Different?
 Most animals-move from place to place on their own, find food, produce young
 Scientists group animals into two groups:
1. Animals with a backbone
2. Animals without a backbone {A backbone in the main bone
that runs down the middle of the back of some animals. The backbone is made up of joined smaller
bones.}
Animals with no backbone
 Make up the largest group of animals
 Can be found in the water, land, and air
 Animals in this group are very different from each other
 Range in size from very tiny to larger than some whales
 Examples: mites, squid, insects, sea stars, worms, snails, sponges, jellyfish
Animals with backbones
 Make up the smallest group of animals
 Can be found in the water, land, and air
 Range in size from very small to large like whales
 Examples: cat, whale, birds, snakes, horses, fish
Insects and Animals with Jointed Legs
 Insects are the largest group of animals in the world.
 All insects have:
- three body parts: Head, thorax, abdomen
- An exoskeleton (hard outer covering which doesn’t grow, but is replaced by
molting {to shed the outer covering} as the insect grows)
- 3 pairs of jointed legs
 Insects are only animal without backbone that can fly.
 Insects can have 0, 1, or 2 pairs of wings.
 Spiders, lobsters, scorpions, and spider crabs are examples of animals that have two body parts and 4 pairs
of jointed legs.
Lesson 2: How Do Animals with Backbones Vary?
Fish and Amphibians
 Fish are largest group of animals with backbones.
 All fish live in water, throughout the world.
 Body temp of fish is about the same as the water that they are living in. When the temp of the water
changes, the fish’s temperature changes. This makes fish cold-blooded.
 Fins help keep fish upright and steer through water.
 Scales {bony plates that overlap} protect fish bodies
 Gills {feathery structures} are organs that help the fish breathe
water. Gills take in oxygen and let out carbon dioxide.
 Amphibians
 Live in water after hatching from an egg
 Adults can live on land
 Is cold-blooded
 Examples: frogs, toads, salamanders, mud puppies
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Sc. Unit A: Ch.2 guide cont.
Reptiles
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Birds
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Mammals
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Animal with backbone and dry, scaly skin
Are cold-blooded
Found in hot, dry places, rain forests, and other environments
Most lay eggs on land,
Many do not care for their young
Breathe air their entire lives
Examples: snakes, turtles, alligators, lizards
Keep same body temperature making them warm-blooded
Have feathers that cover their bodies,
 Two kinds: small down for trapping heat and
larger, stiff feathers for helping them fly
Have a pair of wings and a pair of legs
Vary greatly in size
Most fly; penguins and ostriches do not
All hatch from eggs
Build nests for their eggs
Care for eggs until they hatch, will care for young
Have hollow bones, making it easier to fly
Has hair and feeds milk to their young
Most have furry coats trap air to keep the animal warm
Live in many different places
Bats are only mammal that flies
Blue whales = largest mammals
Shrew = smallest mammal
Most young are born alive and are cared for by parents or adult animals
3. What Characteristics do Animals Get from Their Parents?
Most animal babies have similar traits of their parents. Can have different coloring, kind of hair, etc.
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Behavior-the way a living thing acts
 Inborn behaviors are ones that are born with and not taught
 Instinct-one type of inborn behavior {ex: squirrel gathering nuts for winter}
 Reflex-simple, automatic behavior controlled by nerves
{blinking} which often protects the animal
 Stimulus = produces a reflex
 Response = reaction to the stimulus
{EX: a large noise is the stimulus, response is that the
animal moves away}
 Learned Behavior
 A taught behavior
 Can be a response to a stimulus
 Learned through watching others especially the adult or mother animals
 Often learned to help them hide for protection or hunt for food
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