11. In general, each species has adapted to a unique role or ecological niche wi
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Question
11. In general, each species has adapted to a unique role or ecological niche within an ecosystem. Some species have ecological niches that seem quite similar. How have wood warblers (small, insect-eating birds) in the boreal forest of Canada evolved ecological niche exclusion even though 4 species of similar-sized wood warbler eat insects in the same type of fir tree at the same time of year? (2 points)
12. __________________ Within an ecosystem, food chains are energy flow systems. What is the fundamental abiotic energy source that drives the entire system? (1 point)
13. Using the Rule of 10, briefly explain why a food chain is usually limited to just a few links. (2 points)
14. Briefly explain how bioaccumulation works within an ecosystem by using as an example, DDT to control insects. (3 points)
15. Over long periods of time, species interacting within an ecosystem develop close interdependence. Occasionally, two species become so dependent upon each other that each directly affects the other’s evolution, a process called coevolution.
Hummingbird pollinated plants have evolved long, red, tubular flowers that provide a lot of nectar in order to attract hummingbirds. What do the plants gain by doing this that they would not otherwise have without it? (2 points)
16._____ Along the Pacific Coast of North America, mussels abound on the shoreline rocks of the intertidal zone. In that ecosystem, the sea star (starfish) is a keystone species because: (1 pt.)
Sea stars keep other species away
Sea stars eat all the mussels
Sea stars eat some of the mussels, which provide room for other species to live on the rocks along with the mussels.
The sea star is not a keystone species in that ecosystem
17. _____In New England, a region in northeastern U.S., abandoned farmland gradually returned to a type of forest with a species mix that was similar to the original forest of the area before conversion to farmland. The first tree species (pioneer species) to take over a field have certain characteristics that enable them to do that particularly well. Which of the following are likely characteristics of the first trees to grow in an abandoned field? (1 point)
a. wide ranging seed dispersal (often wind dispersed)
b. seedlings readily grow in the shade of other trees.
c. grow quickly to keep their place in the sunshine.
d. only one generations in that location as conditions change from field to shady forest
e. all but b.
18. In 1859, Charles Darwin proposed a simple mechanism for species change over time, which has been proven to be a basic principal of biological science.
Major aspects of the mechanism are summarized in the phrase, “natural selection by means of survival of the fittest”:
a) What is meant by “natural selection” in this phrase? (1 point)
b) What did Mr. Darwin mean by the word “fitness”? (1 Point)
19.______ Shortly after the start of the Industrial Revolution, in the area around Manchester, England, industrial pollution killed the lichens that covered the tree trunks and soot settled on the bark causing the formerly light-colored tree trunks to become dark in color. After that, in the local population of peppered moths, dark-colored moths soon began to outnumber light-colored ones. What was the most likely explanation of what brought about this change in the wing color of the moths? (1 point)
a. Light-colored moths migrated to other locations
b. Insect-eating birds could easily see (and eat) light-colored moths against the now dark trunks.
c. Dark-colored moths were faster fliers and could dodge the birds easier
d. The increased warmth of the dark-colored trunks drove away the light colored moths.
20. Plants have no defenses against insects and other animals eating their leaves and other parts.
True b. False
Explanation / Answer
11.May, Yellow-rumped, Black-throated Green, black burnian, and Bay-breasted -- were the subject of a classic study of community ecology (the science of interpreting species interactions). These species often share the same breeding grounds in mature coniferous forests. They had been thought by some ornithologists to occupy the same niche -- in other words, they appeared to assume identical roles in the same bird community. These five warblers would thus be an exception to the ecological rule of competitive exclusion. The rule states that two species with essentially the same niche cannot coexist because one will always out-compete and displace the other.
14.
Accumulation of pesticides or other chemicals in in an organism is refered as bioaccumulation. Substances lost by cataboilism and execrision compare to accumulation toxic materials with in a body causes bioaccumulation. Risk to the environment by toxicity depends on the half life of the substance, the half life of substance is high then it it very risk to environment even the substance content is very low. Bioaccumulation of chemicals in a organism strongly modified by biotrnsformation.
EXAMPLE :
Dichlorodiphenyltrichloroethane (DDT) known for its insecticidal properties and impact on environment (DDT), it is a colorless, crystalline, tasteless, and almost odorless organochlorine. known for its insecticidal properties and environmental impacts. DDT is in different forms such as solutions in xylene or petroleum distillates, emulsifiable concentrates, water-wettable powders, granules, aerosols, smoke candles and charges for vaporizers and lotions.
DDT causses evantual death of insects because sodium ions of DDT acts on open network of insects and cause them fire. DDT action resisted by certain insects with certain mutations. Toxins in metabolism into inactive metabolism caused by greater quantity accumulation of DDT tissuse.
15.
Answer:
In the evolutionary processes, every organism tries to fit, survive and replicates to cope up with the harsh environmental conditions, like wise plants also do the same.
To attract the hummingbirds, such plants evolved long, red and tubular flowers, if there were no hummingbirds, plants would have evolved other mechanisms to pollinate themselves.
16.
Answer: option c is the correct one
18a. ANS:
Darwin's Natural selection:
According to the Darwin, It is the process that results in adaptation of an organism to its environment which means of selectivity reproducing changes in the genotype.
In the process of evolution the natural selection is a basic mechanism, it is mainly happens due to the mutations, migrations and genetic drift.
Ex: Some beetles are green in color and some are in brown.
18b. ANS:
Darwin's fitness:
It is the ability of an individual to survive and reproduce in its environment.
Fitness of an organism is measured by how many offspring it produces compared to other individuals of a species.
Adaptation refers to the trait that increases an organism fitness relative to individuals without the trait.
19) Insect eating birds could easily see light colored moths against the now dark trunks.
The light pepper moths were getting spotted easily against the dark background and predators started eating these light colored moths easily and thus the dark ones started outnumbering them.
(20) False
Plants have defenses against insects and other animals eating their leaves and other parts. Plants produces the secondary metabolites (allelochemicals) to repel the plant eating insects or animals and also plants try to grow in locations where herbivores cannot reach them easily. Some plants by having claws, spines or suckers will drove away their enemies and some plants by smelling differently will not allow animals to come near to them.
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