What is class? Biologists put animals into groups that have similar traits in a process called classification. One of the types of groups they put animals in is called a class. Each class has specific traits that make it unique.
Mammals:
Fish:
Birds:
• Have a spine
• Have a spine
• Have a spine
• Warm blooded (can regulate body temp.)
• Cold blooded (can not regulate body temp.)
• Warm blooded (can regulate body temp.)
• Breathe air with lungs
• Use gills to breathe oxygen in
• Breathe air with lungs
• Give birth to live young
water
• Lay eggs
• Produce milk for young
• Lay eggs
• Usually have feathers
• Usually covered in hair or fur
• Most are covered in scales
• Usually capable of flight
Reptiles:
Amphibians:
Arthropods:
• Have a spine
• Have a spine
• Have no spine
• Cold blooded (can not regulate body temp.)
• Cold blooded (can not regulate body temp.)
• Have no red blood cells
• Breathe air with lungs
• Breathe through skin
• Lay eggs
• Lay eggs
• Covered in scales, unlike amphibians
• Go through metamorphosis (body changes shape)
• Have hard exoskeleton • Lay eggs • Most species have six legs (insects) • Have antennae
1
Pick one Using what you have just learned about classes of animals, determine which trait is more important for telling which class an animal is in. Check the box that corresponds to the correct answer.
1.
Fur
OR
Tail
2.
Climbs trees
OR
Warm Blood
3.
Walks upright
OR
Scales
4.
Swims
OR
Gills
5.
Blowhole
OR
Sharp teeth
6.
Feathers
OR
Spots
7.
Eats meat
OR
Six legs
2
Word search Of the traits listed to the right, search for only the ones that belong to mammals such as the giraffe. W C L Y F M M T A U
Z A X U G U L E S H
S B R I J Q R R W B
L E K M P G E A L C
P S L P B H T J W G
B D D A T L H D X G
Y U K A C Q O C P I
Q H E M U S V O L W
F F Q D K L F D D F
L I V E Y O U N G Q
B A N T M Z A G R S
P E E D I P X S F O
Y X G E L E V R Q W
L T G Q K A E V N R
X G I N H N Y I Y X
S S W Q C N H F H H
O H Z X B E Q G K U
V I U H U T C C S E
A I L Y V N I S I P
B N W H T A X B K V
Traits: V K N S L L I G G E
• eggs • warm blood • fur • feathers • scales • milk • antennae • live young • gills
Blowhole
looks can be deceiving Early biologists thought whales and sharks were very similar, but what they discovered came as a big surprise.
Beluga Whale
Hammerhead Shark Gills
What they thought: When the earliest biologists were first discovering animals, they had not yet learned how to divide them into classes. So naturally, when they came across whales and sharks swimming through the oceans, they assumed that they were similar. They both were generally large in size and they shared many of the same habitats. Some sharks and whales even have similar diets. How could two animals with seemingly so much in common be so different? The answer lies in their classes.
What they discovered: The biggest realization biologists had when it came to the relationship between sharks and whales was that they are in different classes. Sharks are fish, and whales are mammals. Why does this make them so different? Most importantly, sharks use gills to breathe in the water, while whales have lungs and need to come up to the surface to breathe out of a blowhole. Sharks are cold blooded and can’t regulate their body temperatures, while whales have warm blood and can. Most sharks lay eggs, while all whales give birth to live young and produce milk to feed them. Sharks have skin made up of tiny scales, and whales have soft, smooth skin. Whales have bones, but sharks don’t! They have cartilage instead. All of those differences can be traced back to the fact that sharks are fish, and whales are mammals. They look similar, but they are not the same at all. In fact, a whale has more in common with another mammal, such as a mouse, than it does with a shark!
reflection
Based on what you have just read, do you think a whale is more similar to you or to a shark. Explain in 2-3 sentences.
3
4
Rank Them Read the descriptions of each animal. Then, rank them from the most similar (1) to the least similar (5) to the bottle-nose dolphin based on class similarities.
Rank:
Bottle-nose Dolphin • Covered in hairless skin • Birth live young, produce milk • Have warm blood • Live in the ocean • Eat small fish and squid • Breathe from a blowhole
Marlin • Covered in scales • Lay eggs • Have cold blood • Live in the ocean • Eat small fish • Breathe from gills
Lion • Covered in fur • Birth live young, produce milk • Have warm blood • Live in savanna grasslands • Eat medium-sized mammals
Great White Shark • Covered in tiny scales • Young develop in eggs in uterus • Have cold blood • Live in the ocean • Eat fish, turtles, sharks, & birds • Breathe from gills • Have no bones, only cartilage
House Fly • Have no spine • Covered in hair-like substance • Lay thousands of eggs • Have no red blood cells • Eat anything in liquid form • Have wings, antennae and 6 legs
Orca Whale
• Covered in hairless skin • Give birth to live young • Have warm blood • Live in the ocean • Eat fish and marine mammals • Breathe from a blowhole