Biology Unit 3
Terms in this set (70)
A mass extinction, in which the dinosaurs disappeared from Earth, occurred approximately
65 million years ago
An unusual, worldwide formation of sedimentary rock called the K-Pg boundary sequence contains the rare element iridium, which is associated with what type of cataclysmic event?
What did Lyell's theory of uniformity propose?
That gradual, repetitive hangs has shaped earth
Darwin incorporated what idea from Malthus into his theory of evolution by natural selection.
That individuals of a population either compete with one another for the limited resources, or develop new technologies to increase productivity
What is the degree of adaptation to a specific environment called?
How do exposed layers of sedimentary rock in the Grand Canyon reveal clues about the geologic time scale?
Chemical composition in each layer reflect conditions on earth when each layer was deposited
After the publication of On the Origin of Species, the idea of evolution was generally accepted. What part of Darwin's theory of evolution, however, was fiercely debated?
In his voyage around the world in the Beagle, what observation did Darwin make about animals?
Organisms that are geographically closer are more closely related
Typically, where would the oldest fossils be found?
deep layer of the Earth
Which factor most greatly influences radioactive decay?
The time it takes for half of the atoms in a radioisotope sample to decay is called what?
When a certain form of a trait increases the fitness of the individual, the frequency of this allele will tend to ____ over time in the population.
Why are the genomes of closely related species more similar than distantly related species?
Neutral mutations accumulate over time
The discovery of immense ridges and trenches stretching thousands of kilometers across the seafloor in the 1950's led to acceptance of the theory of ____.
The supercontinent _____ included the landmasses that are currently found in the southern hemisphere.
The supercontinent that once contained all of Earth's land masses is known as
Bat wings, human forearms, elephant legs, and cat forelimbs are collectively referred to as what?
Homologous structures/ morphological divergence
Similar (nonhomologous) structures that have evolved independently in different lineages that do not share common ancestry are called
Which genes guide the formation of specific body parts during embryonic development?
Comparisons between the cytochrome b protein sequence in the honeycreeper versus the deer mouse and the Gough Island finch reveals eighteen and four amino acid differences, respectively. Describe the evolutionary relationships of these three animals.
The honeycreeper and the finch are more closely related to each other than to the mouse
Cactus spines are modified leaves adapted for dry climates, while the leaves of the Venus fly trap plant are adapted to capture insects. These structures are therefore
Divergent or homologous structures
All vertebrate embryos have four limb buds, a tail, and somites at some point during embryonic development. What does this indicate?
They have a common ancestor
Which of the following events occurred first?
a. evolution of vascular plants
b. evolution of modern humans
c. oxygen accumulation in the Earth's atmosphere
d. evolution of prokaryotes
e. evolution of reptiles
Evolution of prokaryotes
The sum of all the alleles in a population is often referred to as what?
What is the best definition of a population?
Inter breeding, same species and live in the same area
How are new combinations of alleles produced?
Mutations that result in the death of the individual are known as
A ____ mutation changes the DNA sequence but has no impact on the fitness of the individual.
What evolutionary process increases the frequency of adaptive mutations in a population over time.
What is the original source of new alleles?
Fatter sociable weaver birds spend more time foraging where they are vulnerable to predation, are more attractive to predators, and are less likely to escape an attack. Conversely, thin birds risk starvation. Therefore, sociable weaver of an intermediate weight have a selective advantage. This is an example of ____ selection.
In Cameroon, seedcrackers have either small bills (adapted for feeding on soft sedge seeds) or large bills (adapted for feeding on hard sedge seeds). During competition for scarce resources, these birds primarily feed on the seeds for which they are best adapted. This is an example of ____ selection.
In a population of rabbits, those able to outrun predators will survive to reproduce, eventually leading to a population of faster rabbits. This is an example of ____ selection.
Puppies born too large experience difficulties during birthing and tend to have respiratory and other problems. Puppies born too small often can't compete with their siblings for their mother's milk. Thus, puppies of intermediate size have a survival advantage. This is an example of ____ selection.
In a tropical forest some leaves are dark green and some are light green. In a population of caterpillars, homozygous dominant dark green caterpillars thrive eating the dark green foliage, while homozygous recessive light green caterpillars thrive eating light green foliage. However, heterozygous caterpillars of an intermediate color green are easily seen by birds and eaten, thus their numbers are far less than the dominants or recessives. This is an example of ____ selection.
The observation that female lions prefer male lions with darker manes is an example of ____.
A random change in allele frequency over time that is brought about by chance alone is known as
Overhunting of species, such as tigers, reduces their numbers and their genetic diversity. This is an example of
Which population is more likely to be affected by genetic drift? Why?
a. 12 squirrels in a forest
b. 49 herons in a colony
c. 215 fleas on a dog
d. 1350 mice in a house
e. 3000 zebra in a herd
12 squirrels in a forest
The Old Order Amish in Lancaster County is descended from one man and woman and has an unusually high frequency of a recessive allele that causes Ellis-van Creveld syndrome. This is an example of
The movement of alleles among populations is called
Peahens prefer to mate with peacocks that have the brightest and largest tail displays. The peacock's tail is a disadvantage to the males, because it is large and cumbersome and hinders them from escaping from predators. Given these facts, why is the largest male peacock's tail display selected by natural selection?
Because it's coupled with having more babies
Many male birds will expend a great deal of energy building nests. Females will mate with the males who build the best nests. This is best described as an example of ____.
The graphs below show the frequency of the b+ allele over twenty generations in several populations of heterozygous flour beetles (data for populations of ten individuals is shown in graph A; data for populations of one hundred individuals is shown in graph B). Why does the frequency of the b+ allele increase in both populations?
Because it means the allele is adaptive
The increased variability in the frequency of the b+ allele in the smaller flour beetle population in the graph above is an example of what evolutionary process?
A small Dutch population settled in South Africa in the 17th century and became known as Afrikaners. By chance, a few Dutch settlers carried the gene for Huntington's disease. Today, Huntington's disease occurs at a relatively high frequency in this population. This is an example of what phenomenon?
Overhunting of the northern elephant seals left only twenty individuals, from which the modern population arose. As a result, each individual in the modern population is most likely ____ for most alleles.
The migratory patterns of many animals encourage ____.
In Lake Victoria, hundreds of cichlid fish species arose after the lake last dried up 12,400 years ago. This is an example of ____ speciation.
In the 16th century, a Spanish ship explored a Pacific Island that had a small mountain range separating it. Mice that were on the ship escaped onto the island on both sides of the mountain range. After decades of separation the two populations developed different numbers of chromosomes, resulting in reproductive isolation that prevented any future interbreeding. This speciation event is an example of ____ speciation.
With the extinction of the dinosaurs 65 million years ago, multiple niches that the dinosaurs once filled opened up and allowed mammals the opportunity to evolve and exploit those niches. This is an example of what phenomenon?
Over evolutionary time, flowering plants have evolved colors, odors, and nectar that attract pollinating insects and the insects have evolved mechanisms that detect the changes in plants and to better collect pollen. This is an example of
Experiments like those performed by Stanley Miller in the 1850s demonstrated that lightening fueled atmospheric reactions could produce what?
Two researchers suggested in the 1960s that ____ may have been the first informational molecule.
DNA is more stable than RNA for storing genetic information because ____.
RNA breaks and accumulates mutations more often than DNA
Explain why the first organisms on Earth were most likely anaerobic.
Because oxygen was scarce
The appearance of _____ on Earth due to the action of photosynthetic bacteria occurred about 2.7 billion years ago.
Both mitochondria and chloroplasts are thought to have evolved by the process of
What occurs during viral reassortment?
Two related viruses of the same type infect an individual at the same time and swap genes
What is/are a plant's main line of defense against viral infection?
Following infection of a white blood cells by the human immunodeficiency virus (HIV), what does viral reverse transcriptase produce?
A double stranded DNA using viral RNA
Are Archaea more closely related to bacteria or eukaryotes?
What is the name of the structure that allow bacteria to join together to transfer genes?
What kind of bacteria are found inside the roots of legumes, where they receive carbohydrates from the host plant?
Nitrogen fixing bacteria
Genes that are frequently exchanged between prokaryotes are often contained in ____ molecules.
Some bacteria in the deep oceans use iron as an energy source to make carbohydrates from carbon dioxide. These bacteria would be classified as ____.
Bacteria can exchange genes with other bacteria by a method called
You boil water that has been extracted from a swamp and find archaea that are still alive. These archaea are most likely
What unusual molecules are dinoflagellates known to produce?
____ is the best studied species of bacteria.