Section 1-4 Chapter 17 Bio ♥
How do fossils form?
Most fossils are formed in sedimentary rock when water carries small particles from existing rock to lakes and seas. Dead organisms are buried by layers of sediment which forms new rocks.
Could life arise from non life today? Explain.
No, current conditions are life supporting not life generating.
What geologic era is known as the Age of Mammals? When did this era begin?
The Cenezoic Era began about 65 million years ago and continues to the present.
According to the endosymbiotic theory, how might chloroplasts and mitochondria have originated?
The endosymbiotic theory proposes that eukaryotic cells arose from living communities formed by prokaryotic organisms.
What happened at the end of the Paleozoic Era?
95% of animals and plants became extinct,
What is macroevolution? Describe two patterns of macroevolution.
(We can't all have the same answer cause there's six of them, but this is my answer, some of you can use it.) Macroevolution refers to large-scale evolutionary patterns and processes that occur over long periods of time. Convergent evolution is when unrelated organisms come to resemble one another, while extinction is the disappearance of a species from all parts of its geographical range.
How are eras and periods related?
After Precambrian Time, the basic divisions of the geologic time scale are eras and periods.
What is convergent evolution? Describe an example.
Convergent evolution is when unrelated organisms come to resemble one another, such as dolphins and sharks come to resemble one another.
What role have mass extinctions played in the history of life?
Each disappearance of so many species left habitats open and made way for the rapid evolution of new species.
What are the 6 topics of macroevolution?
Extinction, adaptive radiation, convergent evolution, coevolution, punctuated equilibrium, and changes in the developmental genes.
If you were a paleontologist investigating fossils from the Cenezoic Era, what fossils might you find?
Flowering plants, insects, birds, and mammals, including humans.
How might hox genes contribute to variation?
Hox genes regulate timing of genetic control in the embryo. Even small changes in timing can cause variation in traits.
What substances probably made up Earth's early atmosphere?
Hydrogen cyanide, carbon dioxide, carbon monoxide, nitrogen, hydrogen sulfide, and water.
Which type of dating provides an absolute age for a given fossil? Describe how this is done.
In relative dating, paleontologists to estimate a fossil's age compared with that of other fossils. In radioactive dating, scientists calculate the age of a sample based on the amount of remaining radioactive isotopes it contains.
Many more fossils have been found since Darwin's day, allowing several gaps in the fossil record to be filled. How might this information make relative dating more accurate?
Index fossils enable scientists to date the rock layer in which it is found. Scientists can also use them to date rocks from different locations.
What molecules were the end products to Miller and Urey's experiments?
Miller and Urey's experiments suggested how simple compounds found on the early Earth could have combined to form the organic compounds needed for life.
Compare and contrast the hypotheses of gradualism and punctuated equilibrium.
Punctuated equilibrium is the pattern of long, stable periods interrupted by brief periods of more rapid change. Gradualism involves a slow, steady change in a particular line of descent.
What can be learned from the fossil record?
The fossil record provides evidence about the history of life on Earth. It also shows how different groups of organisms, including species, have changed over time.
What are two key events from the Mesozoic Era?
The increasing dominance of dinosaurs and the appearance of flowering plants.
How did the addition of oxygen to Earth's atmosphere affect life of that time?
The rise of oxygen in the atmosphere drove some life forms to extinction, while other life forms evolved new, more efficient metabolic pathways that used oxygen for respiration.
What evolutionary milestone involving animals occurred during the Devonian period?
animals began to invade the land
Where did life exist during the early Paleozoic era?
in the sea
