What is an Animal?
The process that the body uses to maintain a stable internal environment is called....
homeostasis
What is the highest level of organization an animal can have?
organ systems
Mollusks with two shells are called
bivalves
All vertebrates are ...
chordates
The only animals with feathers are ...
birds
The presence of a____ determines whether an animal is a vertebrate or an invertebrate.
backbone
An animal with many lines of symmetry has ______ symmetry.
radial
An_________ has a system of fluid-filled tubes for obtaining food and oxygen.
echinoderm
A ______ is replaced by a backbonein many vertebrates.
notochord
Into which group of fishes would you classify a fish with jaws and a skeleton made of cartilage?
Cartilaginous fish
What are the 5 main functions of animals?
1. obtain food
2. obtain oxygen
3. maintain homeostasis
4. move
5. reproduce
Describe how the symmetry of a sea star, a sponge, and a fish differ.
A sea star has a radial symmetry. A sponge has no symmetry. A fish has bilateral symmetry.
What is an endoskeleton?
A support system, or skeleton, located on the inside of the body.
Why is the endoskeleton important?
It protects body parts and provides body shape and support.
What characteristics do birds and mammals have in common?
Both are endothermic vertebrates.
Suppose a book titled Earth's Animals is about vertebrates. Is its title a good one?n Explain your answer.
No, the title is misleading. The animals on Earth also include invertebrates.
What is a line of symmetry?
A line that can divide an object or animal into two halves that are mirror images.
If you found a new animal in the ocean, what features would you look for to determine whether it is a mollusk?
Bilateral symmetry, soft body, mantle, and foot.
Whales, polar bears, and seals are endotherms. How might their thick layer of fat help them?
It helps them trap body heat, because they live or swim in cold water.
What is the main difference between the three mammal groups?
Monotremes, marsupials, and placental mammals differ in how their young develop.
Some insects and birds can fly. Despite this similarity, why are insects and birds classified as different groups?
They have different body structure and DNA.
What is radius?
It is the distance from the edge to the center of a circle.
Suppose you see an animal. You wonder if its an arthropod. What characteristics would you look for?
I would look for an exoskeleton, a segmented body, and pairs of jointed appendages.
Would an ectotherm or an endotherm be more active on a cold night? Explain.
Endotherms because they can control their body temperatures. Ectotherms' body temperatures would drop and they couldn't move quickly.
What characterstics do all reptiles share?
They have scaly skin, they have lungs, they lay eggs on land, they breathe air.