Ch 17, 20.1 & 18.2 Test Review

A scientist is using potassium-40, which is a radioactive isotope of potassium, to find the absolute age of a fossil by radiometric dating. The scientist determines that about 3/4 of the original potassium-40 in the fossil now remains in the fossil. --> What additional information is necessary for the scientist to determine the absolute age of the fossil?

• the half-life of potassium-40

• the identity of an index fossil

• the atomic mass of potassium-40

• the total mas of the fossil

A scientist analyzes a fossil found in the limestone layer of Mountain A. By applying the technique of radiometric dating to the fossil, the scientist concludes that the limestone formed approximately 1.34 billion years ago. -->Which of these assumptions is necessary to support the scientist's conclusion?

• After the fossil formed, all of its radioactive isotopes decayed very quickly.

• The fossil formed at the same time as the limestone surrounding it.

• The fossil formed from the same materials as the limestone surrounding it.

• After the limestone formed, chemical and physical processes affected it only minimally.

John states the following claim: "Biogeography provides evidence for the theory of evolution."

To support this claim, which evidence would be MOST useful for John to cite?

• A sequence of fossils shows that horses became smaller over time.

• Polar bears and grizzly bears are similar in many ways, but are adapted to live in different regions.

• Farm crops developed in Asia are now raised successfully in regions all over the world.

• Fossils of plants and animals have been found on Antarctica, which now is covered in ice.

Giraffes, camels & horses share some traits, although they vary in other traits. Which statement accurately describes the evolution of these species?

• Each species descended from an ancient common ancestor.

• All three species evolved from three unrelated ancient ancestors.

• Each species evolved uniquely, without any ancestors.

• Two of the species descended from the other species.

A scientist suggests that the first finch species to arrive on the Galapagos Islands was an insect-eating finch, similar to the modern warbler finch (Certhidea olivacea). If the scientist's suggestion is correct, then how many of the four finch species shown in the diagram could have evolved from the first finch species?

• 1 of the 4 species

• 2 of the 4 species

• 3 of the 4 species

• all 4 species

Darwin developed and proposed the Theory of the Evolution during the 1800's. Since that time, due in part to advances in technology, scientists have expanded their knowledge and ideas about biological systems. Which statement describes an example of evidence acquired in the past 100 years and its relationship to the Theory of Evolution?

• New evidence from molecular biology provides overwhelming support that all life evolved from a single ancestor.

• New evidence from molecular biology provides evidence that life evolved from many ancestors, not a single ancestor.

• New evidence from fossils provides evidence that one species does not descend from another.

• New evidence from bio-geography provides evidence that one species does not descend from another.

Robins typically lay four eggs. Four eggs allow the offspring to be well fed, whereas larger clutches may result in malnourished chicks that have a lower chance of survival. Fewer than four eggs per clutch may result in no surviving offspring if the eggs are preyed upon. Which pattern of natural selection most likely acts to keep four eggs the most common clutch size?

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In a population of goats, both beige-coated and brown-coated goats are better able to blend with the rocky environment than white-coated goats. In this case, the beige and brown coat colors are favored by natural selection over the white color.--> Which type of pattern of natural selection would occur in this scenario?

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American bison were hunted almost to extinction in the late 1800's causing a major decrease in the numbers of bison in America, thus decreasing the genetic diversity. This kind of _______ likely occurred because only a few individuals survived from the original larger population.

• genetic drift

• polygenic shift

• environmental effect

A change in _______ following a large reduction in population size is called a(n) _______.

• habitat conditions; bottleneck effect

• allele frequencies; bottleneck effect

• genetic equilibrium; polygenic effect

• genetic equilibrium; founder effect