题目内容
（请给出正确答案）
A.is; in
B.has been; for
C.uses; with
D.sells; to
参考答案
简答题官方参考答案
（由简答题聘请的专业题库老师提供的解答）
网友提供的答案
更多“This particular material___ quite well, and we believe it will turn out ___ your satisfaction.”相关的问题
Darwin proposed the theory of sexual selection to explain the origin of
ostentatious plumage in certain bird species, maintaining that the ornate
features of males are a consequence of female mate selection based on an
abstract aesthetic sense, not unlike the process of animal breeders producing
(5) fancy-male varieties of pigeons by conscious artificial selection. Wallace
suggested an alternative explanation: through greater physical energy the most
highly adorned males are able to win the competition with rival males.
Meanwhile Huxley pointed out that male adornment is instrumental in
establishing dominance relationships among males: adornment reduces the
(10) physical activity necessary to intimidate rivals.
However, Jacobs later examined the process of female choice, concluding
that what appeared to be choice of an adorned male by a female was really a
mutual attraction to a certain reproductive site. Mate selection requires an
awareness of features characteristic of a suitable breeding site, which might be
(15) mirrored in the ornamentation of the male, and thus mate selection is related
directly to adaptive niche specialization. From this insight, Austin proceeded to
develop a food-courtship theory of mate selection: the population most efficient
in use of the energy available in a particular niche will be the fittest to survive
there. Through natural selection, organisms will tend to become specialized to
(20) form. isolated populations, each adapted to utilize the energy most efficiently
that is available in a particular niche and this process of segregation and
specialization of populations is facilitated by employing in the mating process
samples of the food available in the preferred niche. In particular cases, the
male may display the food to the female or feed it to her in the courtship
(25) ceremony, maybe bearing permanent representations of specific foods on his
plumage, and the female may be attracted to the male for these representations
of the territorial foods.
Austin's theory may be applied to the case for mate choice among
peafowls, whose males' "eyespotted" tail feathers bear a striking resemblance
(30) to blue berries. According to the food-courtship theory, it is because their
plumage bears representations of food that peacocks attract peahens, which may
explain why males with the most "eyespots" on their tail have the greatest
mating success. Not inconsistent with a possible role of the "eyespots" in
reproductive competition among males and in aesthetic selection, this
(35) explanation seems more plausible than the suggestion that by selecting mates
according to the perfection of their tail-feather "eyespots", peahens are able to
identify mates with the greatest "fitness". This process, bringing together
males and females of similar tastes and physiologies, may lead to speciation.
Some of the male display features may come to be involved in species
(40) identification, and it has also been noted that male adornment could have a dual
function, repelling rival males as well as attracting females.
The passage is primarily concerned with
A．contrasting the role of domination and courtship in determining the evolution of bird plumage
B．illustrating the effectiveness of a particular approach to categorizing various evolutionary innovations
C．documenting the origins of a currently accepted scientific theory about food and courtship
D．proposing a new explanation for the evolutionary reasons behind the ornamentation of male bird plumage
E．showing that physical adaptation plays an integral role in contributing to species identification of birds
Darwin proposed the theory of sexual selection to explain the origin of ostentatious
plumage in certain bird species, maintaining that the ornate features of males are a
consequence of female mate selection based on an
Line abstract aesthetic sense, not unlike the process of animal breeders producing
(5) fancy-male varieties of pigeons by conscious artificial selection. Wallace
suggested an alternative explanation: through greater physical energy the most
highly adorned males are able to win the competition with rival males.
Meanwhile Huxley pointed out that male adornment is instrumental in
establishing dominance relationships among males: adornment reduces the
(10) physical activity necessary to intimidate rivals.
However, Jacobs later examined the process of female choice, concluding
that what appeared to be choice of an adorned male by a female was really a
mutual attraction to a certain reproductive site. Mate selection requires an
awareness of features characteristic of a suitable breeding site, which might be
(15) mirrored in the ornamentation of the male, and thus mate selection is related
directly to adaptive niche specialization. From this insight, Austin proceeded to
develop a food-courtship theory of mate selection: the population most efficient
in use of the energy available in a particular niche will be the fittest to survive
there. Through natural selection, organisms will tend to become specialized to
(20) form. isolated populations, each adapted to utilize the energy most efficiently
that is available in a particular niche and this process of segregation and
specialization of populations is facilitated by employing in the mating process
samples of the food available in the preferred niche. In particular cases, the
male may display the food to the female or feed it to her in the courtship
(25) ceremony, maybe bearing permanent representations of specific foods on his
plumage, and the female may be attracted to the male for these representations
of the territorial foods.
Austin's theory may be applied to the case for mate choice among
peafowls, whose males' "eyespotted" tail feathers bear a striking resemblance
(30) to blue berries. According to the food-courtship theory, it is because their
plumage bears representations of food that peacocks attract peahens, which may
explain why males with the most "eyespots" on their tail have the greatest
mating success. Not inconsistent with a possible role of the "eyespots" in
reproductive competition among males and in aesthetic selection, this
(35) explanation seems more plausible than the suggestion that by selecting mates
according to the perfection of their tail-feather "eyespots", peahens are able to
identify mates with the greatest "fitness". This process, bringing together
males and females of similar tastes and physiologies, may lead to speciation.
Some of the male display features may come to be involved in species
(40) identification, and it has also been noted that male adornment could have a dual
function, repelling rival males as well as attracting females.
The passage is primarily concerned with
A．contrasting the role of domination and courtship in determining the evolution of bird plumage
B．illustrating the effectiveness of a particular approach to categorizing various evolutionary innovations
C．documenting the origins of a currently accepted scientific theory about food and courtship
D．proposing a new explanation for the evolutionary reasons behind the ornamentation of male bird plumage
E．showing that physical adaptation plays an integral role in contributing to species identification of birds
How do butterfly ranches and farms operate？ One pioneering project developed by the government of Papua New Guinea encouraged farmers to take part in commercial exploitation of a renewable resource--insects. In the 1970s, government officials became aware that expatriates involved in the commercial collection of insects were enlisting the aid of local farmers who lived adjacent to rainforest habitats. The farmers were paid a small fraction of the market value of the specimens. The government was determined to change this state of affairs to ensure the locals received a larger share of the profit. So the expatriates were expelled from the country, and the Insect Fanning and Trading Agency was born. Most of the trade managed by the IFTA consists of wild-caught insects from rain forests.
In the case of wild-caught butterflies, the majority captured by IFTA collectors are males due to behavioral differences between the sexes. (Males aggregate along river banks to imbibe sodium and are easier to capture.) Because males mate more than once, as long as the harvest of wild populations has the expected skewed sex ratio, the impact of collecting is minimal relative to naturally occurring predation. Now the IFTA controls all trade in insect specimens and has fostered a program of butterfly ranching to encourage protection of remnant rainforest habitats in the vicinity of a farm or village.
The basic principle behind butterfly ranching is diversification of crops in a small garden plot to include the host-plants on which caterpillars feed. Only a small fraction of these larval host-plants are known to science. The main "research and development" activity of butterfly ranchers is discovering unknown host-plants through careful observation of egg-laying female butterflies. Once the host of a particular species is known, it can be cultivated in the garden near the edge of the rain forest to attract egg-laying females. If the natural concentration of a particular plant species is one per square mile of rain forest, and a farmer plants several dozen of the species, the result is a dense concentration of caterpillars in a short time. Butterfly ranching thus involves artificial manipulation of the natural density of caterpillar host-plants.
Additionally, flowering plants, such as Hibiscus and Lantana, attract female butterflies, which need the nectar to renew their energy reserves after a bout of egg-laying. After the caterpillars mature, they are harvested and removed to cages for pupation. The IFTA sends out advisors to instruct villagers in butterfly husbandry techniques. Many farmers have learned that they can sell butterflies to supplement their income if they protect the remnant patches of rain forest that form. a reservoir for this renewable resource.
Along with the studies of butterflies, ______ emerges.
A．academy's newest exhibit
B．a model organism
C．a farm
D．a new business
Part of the reason is technical. Understanding. and then altering, the genes of a big pine tree are more complex than creating a better tomato. While tomatoes sprout happily, and rapidly, in the laboratory, growing a whole tree from a single, genetically altered cell in a test tube is a tricky process that takes years, not months. Moreover. little is known about tree genes. Some trees, such as pine trees. have a lot of DNA-roughly ten times as much as human. And, whereas the Human Genome Project is more than half-way throughits task of isolating and sequencing the estimated 100,00 genes in human cells. similar efforts to analyzetree genes are still just saplings (幼苗).
Given the large number of tree genes and the little that is known about them, tree engineers are starting with a search for genetic "markers". The first step is to isolate DNA from trees with desirable propertiessuch as insect resistance. The next step is to find stretches of DNA that show the presence of a particular gene. Then, when you mate two trees with different desirable properties, it is simple to check which offspring contain them all by looking for the genetic markers. Henry Amerson, at North Carolina State University, is using genetic markers to breed fungal resistance into southern pines. Billions of these are grown across America for pulp and paper, and outbreaks of disease are expensive. But not all individual trees are susceptible. Dr. Amerson’s group has found markers that distinguish fungus-resistant stock from disease-prone trees.Using traditional breeding techniques, they are introducing the resistance genes into pines on test sites in America.
Using generic markers speeds up old-fashioned breeding methods becauseyou no longer have to wait for the tree to grow up to see if it has the desiredtraits. But it is more a sophisticated form. of selective breeding. Now. however.interest in genetic tinkering (基因修补) is also gaining ground. To this end, Dr.Amerson and his colleagues are taking part in the Pine Gene Discovery Project. an initiative to identify and sequence the 50,000-odd genes in the pine tree&39;s genome. Knowing which gene does what should make it easier to know what to alter.
测试题
Compared with genetic engineering of food crops, genetic engineering of trees____________________.
A.began much later
B.has developed more slowly
C.is less useful
D.was less controversial
A mate's receipt is issued by( )．
A．the mate/the master B．the shipowner
C．the shipper D．the consignee
警告：系统检测到您的账号存在安全风险
为了保护您的账号安全，请在“简答题”公众号进行验证，点击“官网服务”-“账号验证”后输入验证码“”完成验证，验证成功后方可继续查看答案！
