when every individual of a species dies out
extrinction
The "one bone"- "two bones" - "many bones" indicates __________
limb bones develop randomly w/no evolutionary significance
tetrapods first evolved wings instead of legs
tetrapods evolved completely independently
all tetrapods share a common ancestor.
traces of organisms' activities; burrows, footprints, drag marks
trace fossil
During which period did the first tetrapods appear?
Devonian
Silurian
Ordovician
Cambrian
Why is this bone pattern important?
It only applies to birds
shows a common ancestor, how limbs adapted for environments
shows that vertebrate limbs are all completely different
It proves that fish could not evolve into land animals
A fossil shows evidence of a tetrapod living in shallow water 375 million years ago. What does this suggest about the transition from aquatic to land animals?
Land plants forced animals to leave the water
All animals had already moved completely onto land
Some vertebrates were beginning to adapt to life on land
Tetrapods lived only in the deepest parts of the ocean
remains of the actual organism; shells, bones, teeth preserved
body fossil
variety of living organisms in a particular area or on Earth as a whole
biodiversity
What was the main type of life during the Ordovician Period?
Mammals
Marine invertebrates like brachiopods and mollusks
Dinosaurs
Birds
a collection of fossils that give clues to the history of life on Earth
fossil record
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
Fossilization is rare, soft-bodied organisms decay, and many
Scientists have already found every fossil on Earth
Which of the following animals does NOT follow the one → two → many → digits pattern?
Amphibians
Humans
Fish
None of the above; all follow the pattern
Which type of organisms is least likely to appear in the fossil record?
Fish with bones
Animals with shells
Soft-bodied organisms like worms and jellyfish
Dinosaurs
What would a paleontologist NOT do?
Study fossils to learn about ancient life.
Use rock layers to determine the age of fossils.
Track the migration of living animals
Compare fossil evidence to modern organisms.
Which of the following correctly describes the “one bone → two bones → many bones → digits” pattern?
Does not relate to evolution
Only found in humans
Shows how vertebrate limbs are related and adapted
Only occurs in fish
states that oldest rocks are on the bottom while younger ones are close to the top
law of superpositions
a vertebrae with 4 limbs (birds, amphibians, reptiles, mammals)
tetrapod
Why are land plants important in evolution?
They produced shells for protection
They allowed animals to colonize land
They could fly
They replaced fish in oceans
Fossilization requires certain conditions. Which of the following helps a fossil form?
Being eaten by predators
Rapid burial in sediment
Exposure to air and sunlight
Floating on the ocean surface
In a sequence of rock layers, what would scientists expect to find in the youngest (top) layer?
Fossils of dinosaurs only
Fossils of simple bacteria and algae
Fossils of early marine animals from the Cambrian Period
Fossils of mammals, birds, flowering plants, and humans
During the Cambrian Period, most life forms were aquatic. What does the fossil record from this time reveal?
Large dinosaurs living on land and in the oceans
Land plants and forests covering Earth’s continents
Water covered the majority of the Earth
Humans and mammals becoming the dominant life forms
In a sequence of rock layers, what would scientists expect to find in the oldest (bottom) layer?
Fossils of early life forms like algae or marine animals
Fossils of mammals and humans
Fossils of flowering plants and insects
Fossils of birds and dinosaurs
Why didn’t the soft parts of early animals usually fossilize?
Fossils can only form in very cold climates
Early animals lived only on land, far from where fossils for
Soft tissues decayed or were eaten before they preserved
Soft parts were too small to be seen by scientists
What does a cladogram show?
The size of organisms
Evolutionary relationships among organism
The age of rocks
The order in which fossils are found
the prefix "terre" means
land/earth
Organisms that share more traits on a cladogram are:
Always the same species
more closely related
Less closely related
The same age
What is the significance of the “digits” in the pattern?
They are just for decoration
They make the limb shorter
allow animals to swim, walk, climb, or manipulate objects
They are only found in humans
Which of the following can studying embryos help scientists understand?
The exact color of an adult animal
How species may be related through common ancestors
Which species is the smartest
How fast an animal can run
organism that comes before descendants
ancestor
a trait that evolves over time from common ancestor
derived trait
Which two animals are most closely related according to the cladogram?
Horse and tortoise
Leopard and house cat
Wolf and tortoise
Horse and tortoise
an unborn organism in the very early stages of development
embryo
Early tetrapods were fully aquatic but were developing structures that would later allow movement on land
this occured during the Permian Period
this occured during the Devonian Period
this occured during the Cambrian Period
this occured during the Jurassic Period
Which statement best describes biodiversity?
Dinosaurs were the only contributors to biodiversity
Only marine animals existed until the Mesozoic
it gradually increased when animals moved onto land
Stayed the same until humans appeared
evolutionary tree; shows ancestors, descendants, over a long time
cladogram
process where organisms change/diversify over a long time
evolution
a scientist who studies fossils
paleontologist
any living thing that can carry out life processes on its own
organism
Dolphin embryos show four limbs, and baby dolphins are born with hair. Why is it important for scientists to study embryos as well as adult organisms?
Adult organisms do not have any bones.
embryos helps scientists predict the size of the adult anima
embryos can show features that isn't seen in adults
Embryos are easier to observe than adults.
What were the first organisms on Earth?
amphibians
land plants
dinosaurs
Single-celled prokaryotes
the remains of ancient organisms
fossil
layered rock formed as sediments compress and cement togetherp; often contains fossils
sedimentary rock
the prefix "tetra" means ____
four
Which animal is least closely related to the others?
wolf
horse
tortoise
kitty cat
organism that comes after ancestors
descendants