Share 7th Grade Science Unit 1 - early life
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Why doesn’t the fossil record show all organisms that have ever existed?
All organisms are equally likely to become fossils
Most organisms never lived long enough to be important
Scientists have already found every fossil on Earth
Fossilization is rare, soft-bodied organisms decay, and many
Fossilization requires certain conditions. Which of the following helps a fossil form?
Rapid burial in sediment
Exposure to air and sunlight
Being eaten by predators
Floating on the ocean surface
What is the significance of the “digits” in the pattern?
allow animals to swim, walk, climb, or manipulate objects
They make the limb shorter
They are just for decoration
They are only found in humans
Why is this bone pattern important?
shows a common ancestor, how limbs adapted for environments
It only applies to birds
It proves that fish could not evolve into land animals
shows that vertebrate limbs are all completely different
Which of the following animals does NOT follow the one → two → many → digits pattern?
Amphibians
Fish
None of the above; all follow the pattern
Humans
What were the first organisms on Earth?
dinosaurs
land plants
amphibians
Single-celled prokaryotes
During which period did the first tetrapods appear?
Cambrian
Silurian
Devonian
Ordovician
Why are land plants important in evolution?
They produced shells for protection
They replaced fish in oceans
They allowed animals to colonize land
They could fly
What was the main type of life during the Ordovician Period?
Dinosaurs
Birds
Mammals
Marine invertebrates like brachiopods and mollusks
Which of the following correctly describes the “one bone → two bones → many bones → digits” pattern?
Only found in humans
Does not relate to evolution
Only occurs in fish
Shows how vertebrate limbs are related and adapted
Which type of organisms is least likely to appear in the fossil record?
Dinosaurs
Soft-bodied organisms like worms and jellyfish
Animals with shells
Fish with bones
What does a cladogram show?
Evolutionary relationships among organism
The size of organisms
The order in which fossils are found
The age of rocks
Organisms that share more traits on a cladogram are:
more closely related
Less closely related
The same age
Always the same species
Which two animals are most closely related according to the cladogram?
Leopard and house cat
Wolf and tortoise
Horse and tortoise
Horse and tortoise
Which animal is least closely related to the others?
kitty cat
horse
wolf
tortoise
During the Cambrian Period, most life forms were aquatic. What does the fossil record from this time reveal?
Water covered the majority of the Earth
Large dinosaurs living on land and in the oceans
Humans and mammals becoming the dominant life forms
Land plants and forests covering Earth’s continents
