BellWork (2/24-3/5) Flashcards
In northern Canada, a population of rabbits was predominantly white in color. The allele for white color is recessive while the allele for gray color is dominant. Over the last several decades, the average annual temperature of this area has increased and the long-term deposits of ice and snow have become scarce. In this case, the frequency of a previously rare allele becomes more frequent in the population. This is an example of
Directional
A group of scientists is studying Tetragnatha spiders on the island of Hawaii. A large lava flow has divided the spiders’ forest habitat into two parts. As a result, a population of Tetragnatha spiders has become isolated on either side of the hardened lava.
Which of the following best predicts how the lava flow will affect the spider populations over time?
The spider population on each side of the lava flow will become reproductively isolated.
A scientist studies three populations of frog (populations A, B, and C) that live in the same rainforest. He notices some interesting similarities between the three groups. What would be the best evidence that A and B have a more recent common ancestor than A and C or B and C?
Populations A and B share similar mitochondrial DNA sequences
A simplified evolutionary path of the whale is shown. What is the best evidence to support the relationship of the modern whale to the immediate ancestor in the evolutionary path?
The presence of rudimentary hip bones in the whale
Select the best statement.
analogous structures are evidence of convergent evolution while homologous structures are evidence for divergent evolution
The figure below shows alligator and mouse embryos sharing the similarity of limb bud development. What evidence is supported by the alligator and mouse embryos sharing similarities during development?
These organisms have a related ancestor
Flesh-eating parasitizing maggots are the offspring of the fly, Ormia ochracea, which invaded Hawaii from North America. The adult flies follow the chirps of a calling cricket and then deposit wriggling maggots onto the cricket’s back. The maggots burrow into the cricket, and emerge, a week later, killing the cricket in the process. Between 1991 and 2001, there were documented major declines in the island’s cricket population. In one study, 30% of calling males were infested with the parasite, and in 2001, the island was virtually silent. But in 2003, the cricket population had rebounded. Crickets were back but they were silent crickets! What is the BEST explanation of how this happened?
Some silent crickets existed that were genetically different. They survived and reproduced. Over time, that population grew.
In the late 1940’s, scientists released a group of chemicals, pyrethroids, to help kill insects in auricular crops. By the year 2000, over 100 insect species were resistant to pyrethroids and scientists had to develop a new plan to kill them. Explain what happened genetically in the insect population over time as the insects were exposed to pyrethroids.
The allele for pyrethroid resistance increased throughout the population.
Many species have embryos that look similar to one another and develop similar structures. Refer to the picture above. During the first stage of embryonic development for each species, what type of evolution could you conclude about the relatedness of the organisms?
Divergent evolution because all of the species start to differentiate as they develop.
If a severe freezing event results in the ground being covered with frost for several days killing many of the ants that live close to the ground’s surface, what is the likely effect on the population of ants after the ground thaws?
The genetic diversity in the ant population will decrease since the population size decreased.
Hunting reduced the population size of the northern elephant seal to as few as 20 individuals at the end of the 19th century. Their population has since rebounded to over 30,000, but they have much less genetic variation than a population of southern elephant seals that was not so intensely hunted. How is the lack of genetic variation related to the hunting episodes of the 1800’s?
Genetic drift occurred: the few individuals left behind were the seals that passed on that specific gene pool.
Light-colored rock pocket mice blend in with sandy soil of the area, but stand out on dark lava flow, making them easy prey for visual predators. A gene mutation produced a darker fur color that makes some mice better able to survive predators in the lava environment. Over time, the darker colored mice became more common in the area of the lava flow. Why did dark colored rock pocket mice first appear in the population?
They have a random gene mutation that affects their fur color.
Cystic fibrosis is a recessive, single-gene genetic disorder that affects mainly lung cells. It produces abnormally thick mucus, making breathing very difficult. Which best explains how this disorder is passed on to offspring from unaffected parents?
Both parents must be carriers of the allele.
The allele for white color is recessive (g) while the allele for gray color is dominant (G). What is the most likely genotypes of the population rabbits living in northern Canada in 1850?
85% gg and 15% Gg
In England, peppered moths have two color forms, light and dark. Dark is a dominant trait. Until about 1850, the majority of moths in England were light colored. With the beginning of the Industrial Revolution in the late 1800’s the moth population began to change color. The majority of the moths were dark by the 1920’s. How can this be explained genetically?
As the light colored moths were seen and eaten, the allele for dark color became more prevalent in the population.
What is a major difference between sexual and asexual reproduction?
asexual reproduction does not increase genetic variation
