Biology 103 Chapter 13
Terms in this set (20)
The name of the specialized field of studies that examines fossils and other clues to past life or environmental conditions is
Fossils may be
casts from footprints that have filled with mud and then turned to stone.
from impressions left after an organism decays.
----All of the answer choices are correct.
formed when plant resin or tar preserves the specimen.
formed as organic matter is replaced by minerals, turning to stone.
Petrification occurs when
minerals replace the organic material left by a decaying organism.
Absolute dating uses ______ to estimate how old a fossil is.
If an isotope's half-life is 100 years,
in 100 years, only half of the atoms in a sample of that isotope will remain.
According to Plate Tectonics Theory, Earth once consisted of a single, large landmass named
The large, rigid layers of Earth's surface that are moving in response to forces deep within Earth, are called
If similarities between two structures in different organisms reflect common ancestry, these structures are
If similarities between two structures in different organisms reflect independent evolution, these structures are
If a structure has no apparent function in one species, yet is homologous to a functional organ in another species, this structure is termed
The half life of 14C is 5,730 years. 11,460 years after an organism dies, what percent of the initial 14C will still be present in the organism's bones?
The half life of 14C is 5,730 years. If you test a fossilized bone and find that it has 1/8th the 14C as a modern bone, you could conclude that it is approximately __ years old.
5,730 × 8 = 42,960
The forelimb of a bat and the forelimb of a bird are examples of ______ structures.
The wing of a bat and an insect are examples of _____ structures.
The femur in a snake and pelvis in a whale are examples of _____ structures.
The observation that most aquatic vertebrates (e.g. fish, penguins, and whales) have streamlined bodies and fins or flippers for steering are a result of
Amphibians, birds, and mammals look the most similar as
The number of differences between human cytochrome c and cytochrome c of some other organisms is as follows: rhesus monkey - 1 difference; pigeon - 12 differences; fruit fly - 24 differences. The order in which these species are most similar to humans is
rhesus monkey, pigeon, fruit fly.
If many human genes differ in about 10% of their bases from another species' same genes and substitutions occur at an estimated rate of 2% per one million years, then about _____ years have passed since the two species diverged.
Why do different mutations accumulate in two species once they diverge?
They can no longer mate and swap the mutation.