Red
What is the most resilient species on earth?
Tardigrade
Some scientists believe that life on Earth began about 3.5 billion years ago. What do they base this belief on?
the fossil record
Define _______
JK!!! EXTRA CREDIT! +2
12. As the body plan of the fish progressed, the first sharks appeared during the Silurian Period. The skeletons of these ancient fish are hard to find in fossil form because their skeletons are composed of _____________.
cartilage
According to the current fossil record, scientists believe that life on Earth began about how long ago?
3. 5 billion years
For the most part, fossils give us information about the ________________ of past life forms.
structure
Finding a fossil sample that also contained seashells would indicate that the living organism had died near _____________________.
An ocean
The death of the dinosaurs occurred as part of _______.
Mass extinction
Earth is the only planet in our solar system known to have _______.
life
Scientists frequently use all of the following to support the theory that organisms change over time except
similarities in number of mates
In what era did the first land plants appear?
Paleozoic
Fossils such as __________ provide evidence of past life and environmental conditions.
Footprints and shells
Scientists sometimes find trace fossils that are not the organism itself, but something left behind by an organism. Coprolites are trace fossils. They are preserved feces, or dung, from animals. What part of an organism's life can this tell scientists about?
diet
Why are index fossils good indicators of geologic time?
They lived during a short period of geologic time.
Mercury, Venus, Earth, and Mars are all inner planets. Identify one unique characteristic of Earth that makes life possible here.
Earth has liquid water.
Over millions of years, animals have evolved in shape and size. The nautiloid is one of those animals. Which of
the following is a descendent of the nautiloid found during the Cambrian period?
nautilus
What is the importance of studying fossils?
to provide information about how life and environmental conditions may have changed
When scientists analyze the fossil record, they find organisms that are similar to some organisms of today with noticeable changes. How does this help scientists to interpret the past?
It allows them to see how organisms have changed over time.
Critique this statement: Earth is the only body in the solar system that supports life because it is the third planet from the sun.
The statement is partly true because being the third planet from the sun means temperatures on Earth are not too hot or too cold.
Agnathans' living relatives are thought to be the ________ and _________.
Lamprey, hagfish