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[A] : Endomycorrhiza of forest trees con...

[A] : Endomycorrhiza of forest trees contribute to the efficient nutrient cycling in tropical test ecosystems .
[R] : The fungi that form endomycorrhizal association with plants store nutrient ions and make them available to the host plants .

A

If both A and R are true and R is the correct explanation of A

B

If both A and R are true but R is not the correct explanation of A

C

If A is true and R is false

D

If both A and R are false

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Assertion : Endomycorrhiza of forest trees contribute to the efficient nutrient cycling in tropical forest ecosystem. Reason : The fungi that form mycorrhizal associations with plants make nutrient ions available to them.

Assertion : Endomycorrhiza of forest trees contribute to the efficient nutrient cycling in tropical forest ecosystem. Reason : The fungi that form mycorrhizal associations with plants make nutrient ions available to them.

Knowledge Check

  • Honey bees are hosts to the pathogenic large ectoparasitic mite Varroa destructor (Varroa mites). These mites feed on bee hemolymph (blood) and can kill bees directly or by increasing their susceptibility line 5- to secondary infection with fungi, bacteria or viruses. Little is known about the natural defenses that keepthe mite infections under control. Pyrethrums are a group of flowering plants which include Chrysanthemum coccineum, Chrysanthemum line 10- cinerariifolium, Chrysanthemum marschalli, and related species. These plants produce potent insecticides with anti-mite activity. The naturally occurring insecticides are known as pyrethrums. A synonym for the naturally occurring pyrethrums is line 15- pyrethrin and synthetic analogues of pyrethrums are known as pyrethroids. In fact, the human mite infestation known as scabies (Sarcoptes scabiei) is treated with a topical pyrethrum cream. We suspect that the bees of commercial bee line 20- colonies which are fed mono-crops are nutritionally deficient. In particular, we postulate that the problem is a diet deficient in anti-mite toxins: pyrethrums, and possibly other nutrients which are inherent in such plants. without, at least, intermittent feeding on line 25- the pyrethrum producing plants, bee colonies are susceptible to mite infestations which can become fatal either directly or due to a secondary infection of immunocompromised or nutritionally deficient bees. This secondary infection can be viral, bacterial or line 30- fungal and may be due to one or more pathogens. In addition, immunocompromised or nutritionally deficient bees may be further weakened when commercially produced insecticides are introduced into their hives by bee keepers in an effort to fight line 35- mite infestation. We further postulate that the proper dosage necessary to prevent mite infestation may be better left to the bees, who may seek out or avoid pyrethrum containing plants depending on the amount necessary to defend against mites and the line 40- amount already consumed by the bees, which in higher doses could be potentially toxic to them. This hypothesis can best be tested by a trial wherein a small number of commercial honey bee colonies are offered a number of pyrethrum line 45- producing plants, as well as a typical bee food source such as clover, while controls are offered only the clover. Mites could then be introduced to each hive with note made as to the choice of the bees, and the effects of the mite parasites on the experimental line 50 - colonies versus control colonies. It might be beneficial to test wild-type honey bee colonies in this manner as well, in case there could be some genetic difference between them that affects the bees’ preferences for pyrethrum producing flowers. How do the words “can,” "may,” and “could” in the hird paragraph (lines 19-41) help establish the tone of the paragraph?

    A
    They create an optimistic tone that makes clear the authors are hopeful about the effects of their research on colony collapse disorder.
    B
    They create a dubious tone that makes clear the authors do not have confidence in the usefulness of the research described.
    C
    They create a tentative tone that makes clear the authors suspect but do not know that their hypothesis is correct
    D
    They create a critical tone that makes clear the authors are skeptical of claims that pyrethrums are inherent in mono-crops.

  • Honey bees are hosts to the pathogenic large ectoparasitic mite Varroa destructor (Varroa mites). These mites feed on bee hemolymph (blood) and can kill bees directly or by increasing their susceptibility line 5- to secondary infection with fungi, bacteria or viruses. Little is known about the natural defenses that keepthe mite infections under control. Pyrethrums are a group of flowering plants which include Chrysanthemum coccineum, Chrysanthemum line 10- cinerariifolium, Chrysanthemum marschalli, and related species. These plants produce potent insecticides with anti-mite activity. The naturally occurring insecticides are known as pyrethrums. A synonym for the naturally occurring pyrethrums is line 15- pyrethrin and synthetic analogues of pyrethrums are known as pyrethroids. In fact, the human mite infestation known as scabies (Sarcoptes scabiei) is treated with a topical pyrethrum cream. We suspect that the bees of commercial bee line 20- colonies which are fed mono-crops are nutritionally deficient. In particular, we postulate that the problem is a diet deficient in anti-mite toxins: pyrethrums, and possibly other nutrients which are inherent in such plants. without, at least, intermittent feeding on line 25- the pyrethrum producing plants, bee colonies are susceptible to mite infestations which can become fatal either directly or due to a secondary infection of immunocompromised or nutritionally deficient bees. This secondary infection can be viral, bacterial or line 30- fungal and may be due to one or more pathogens. In addition, immunocompromised or nutritionally deficient bees may be further weakened when commercially produced insecticides are introduced into their hives by bee keepers in an effort to fight line 35- mite infestation. We further postulate that the proper dosage necessary to prevent mite infestation may be better left to the bees, who may seek out or avoid pyrethrum containing plants depending on the amount necessary to defend against mites and the line 40- amount already consumed by the bees, which in higher doses could be potentially toxic to them. This hypothesis can best be tested by a trial wherein a small number of commercial honey bee colonies are offered a number of pyrethrum line 45- producing plants, as well as a typical bee food source such as clover, while controls are offered only the clover. Mites could then be introduced to each hive with note made as to the choice of the bees, and the effects of the mite parasites on the experimental line 50 - colonies versus control colonies. It might be beneficial to test wild-type honey bee colonies in this manner as well, in case there could be some genetic difference between them that affects the bees’ preferences for pyrethrum producing flowers. Which choice provides the best evidence for the answer to the previous question?

    A
    Lines 3-5 (“These mites... viruses”)
    B
    Lines 16-18 (“In fact... cream”)
    C
    Lines 19-21 (“We suspect... deficient”)
    D
    Lines 24-28 (“Without... bees”)

  • Honey bees are hosts to the pathogenic large ectoparasitic mite Varroa destructor (Varroa mites). These mites feed on bee hemolymph (blood) and can kill bees directly or by increasing their susceptibility line 5- to secondary infection with fungi, bacteria or viruses. Little is known about the natural defenses that keepthe mite infections under control. Pyrethrums are a group of flowering plants which include Chrysanthemum coccineum, Chrysanthemum line 10- cinerariifolium, Chrysanthemum marschalli, and related species. These plants produce potent insecticides with anti-mite activity. The naturally occurring insecticides are known as pyrethrums. A synonym for the naturally occurring pyrethrums is line 15- pyrethrin and synthetic analogues of pyrethrums are known as pyrethroids. In fact, the human mite infestation known as scabies (Sarcoptes scabiei) is treated with a topical pyrethrum cream. We suspect that the bees of commercial bee line 20- colonies which are fed mono-crops are nutritionally deficient. In particular, we postulate that the problem is a diet deficient in anti-mite toxins: pyrethrums, and possibly other nutrients which are inherent in such plants. without, at least, intermittent feeding on line 25- the pyrethrum producing plants, bee colonies are susceptible to mite infestations which can become fatal either directly or due to a secondary infection of immunocompromised or nutritionally deficient bees. This secondary infection can be viral, bacterial or line 30- fungal and may be due to one or more pathogens. In addition, immunocompromised or nutritionally deficient bees may be further weakened when commercially produced insecticides are introduced into their hives by bee keepers in an effort to fight line 35- mite infestation. We further postulate that the proper dosage necessary to prevent mite infestation may be better left to the bees, who may seek out or avoid pyrethrum containing plants depending on the amount necessary to defend against mites and the line 40- amount already consumed by the bees, which in higher doses could be potentially toxic to them. This hypothesis can best be tested by a trial wherein a small number of commercial honey bee colonies are offered a number of pyrethrum line 45- producing plants, as well as a typical bee food source such as clover, while controls are offered only the clover. Mites could then be introduced to each hive with note made as to the choice of the bees, and the effects of the mite parasites on the experimental line 50 - colonies versus control colonies. It might be beneficial to test wild-type honey bee colonies in this manner as well, in case there could be some genetic difference between them that affects the bees’ preferences for pyrethrum producing flowers. The passage most strongly suggests that beekeepers’ attempts to fight mite infestations with commercially produced insecticides have what unintentional effect?

    A
    They increase certain mite populations.
    B
    They kill some beneficial forms of bacteria
    C
    They destroy bees’ primary food source.
    D
    They further harm the health of some bees.

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    Honey bees are hosts to the pathogenic large ectoparasitic mite Varroa destructor (Varroa mites). These mites feed on bee hemolymph (blood) and can kill bees directly or by increasing their susceptibility line 5- to secondary infection with fungi, bacteria or viruses. Little is known about the natural defenses that keepthe mite infections under control. Pyrethrums are a group of flowering plants which include Chrysanthemum coccineum, Chrysanthemum line 10- cinerariifolium, Chrysanthemum marschalli, and related species. These plants produce potent insecticides with anti-mite activity. The naturally occurring insecticides are known as pyrethrums. A synonym for the naturally occurring pyrethrums is line 15- pyrethrin and synthetic analogues of pyrethrums are known as pyrethroids. In fact, the human mite infestation known as scabies (Sarcoptes scabiei) is treated with a topical pyrethrum cream. We suspect that the bees of commercial bee line 20- colonies which are fed mono-crops are nutritionally deficient. In particular, we postulate that the problem is a diet deficient in anti-mite toxins: pyrethrums, and possibly other nutrients which are inherent in such plants. without, at least, intermittent feeding on line 25- the pyrethrum producing plants, bee colonies are susceptible to mite infestations which can become fatal either directly or due to a secondary infection of immunocompromised or nutritionally deficient bees. This secondary infection can be viral, bacterial or line 30- fungal and may be due to one or more pathogens. In addition, immunocompromised or nutritionally deficient bees may be further weakened when commercially produced insecticides are introduced into their hives by bee keepers in an effort to fight line 35- mite infestation. We further postulate that the proper dosage necessary to prevent mite infestation may be better left to the bees, who may seek out or avoid pyrethrum containing plants depending on the amount necessary to defend against mites and the line 40- amount already consumed by the bees, which in higher doses could be potentially toxic to them. This hypothesis can best be tested by a trial wherein a small number of commercial honey bee colonies are offered a number of pyrethrum line 45- producing plants, as well as a typical bee food source such as clover, while controls are offered only the clover. Mites could then be introduced to each hive with note made as to the choice of the bees, and the effects of the mite parasites on the experimental line 50 - colonies versus control colonies. It might be beneficial to test wild-type honey bee colonies in this manner as well, in case there could be some genetic difference between them that affects the bees’ preferences for pyrethrum producing flowers. Which choice provides the best evidence for the answer to the previous question?

    Honey bees are hosts to the pathogenic large ectoparasitic mite Varroa destructor (Varroa mites). These mites feed on bee hemolymph (blood) and can kill bees directly or by increasing their susceptibility line 5- to secondary infection with fungi, bacteria or viruses. Little is known about the natural defenses that keepthe mite infections under control. Pyrethrums are a group of flowering plants which include Chrysanthemum coccineum, Chrysanthemum line 10- cinerariifolium, Chrysanthemum marschalli, and related species. These plants produce potent insecticides with anti-mite activity. The naturally occurring insecticides are known as pyrethrums. A synonym for the naturally occurring pyrethrums is line 15- pyrethrin and synthetic analogues of pyrethrums are known as pyrethroids. In fact, the human mite infestation known as scabies (Sarcoptes scabiei) is treated with a topical pyrethrum cream. We suspect that the bees of commercial bee line 20- colonies which are fed mono-crops are nutritionally deficient. In particular, we postulate that the problem is a diet deficient in anti-mite toxins: pyrethrums, and possibly other nutrients which are inherent in such plants. without, at least, intermittent feeding on line 25- the pyrethrum producing plants, bee colonies are susceptible to mite infestations which can become fatal either directly or due to a secondary infection of immunocompromised or nutritionally deficient bees. This secondary infection can be viral, bacterial or line 30- fungal and may be due to one or more pathogens. In addition, immunocompromised or nutritionally deficient bees may be further weakened when commercially produced insecticides are introduced into their hives by bee keepers in an effort to fight line 35- mite infestation. We further postulate that the proper dosage necessary to prevent mite infestation may be better left to the bees, who may seek out or avoid pyrethrum containing plants depending on the amount necessary to defend against mites and the line 40- amount already consumed by the bees, which in higher doses could be potentially toxic to them. This hypothesis can best be tested by a trial wherein a small number of commercial honey bee colonies are offered a number of pyrethrum line 45- producing plants, as well as a typical bee food source such as clover, while controls are offered only the clover. Mites could then be introduced to each hive with note made as to the choice of the bees, and the effects of the mite parasites on the experimental line 50 - colonies versus control colonies. It might be beneficial to test wild-type honey bee colonies in this manner as well, in case there could be some genetic difference between them that affects the bees’ preferences for pyrethrum producing flowers. As used in line 35, “postulate” most nearly means to

    Honey bees are hosts to the pathogenic large ectoparasitic mite Varroa destructor (Varroa mites). These mites feed on bee hemolymph (blood) and can kill bees directly or by increasing their susceptibility line 5- to secondary infection with fungi, bacteria or viruses. Little is known about the natural defenses that keepthe mite infections under control. Pyrethrums are a group of flowering plants which include Chrysanthemum coccineum, Chrysanthemum line 10- cinerariifolium, Chrysanthemum marschalli, and related species. These plants produce potent insecticides with anti-mite activity. The naturally occurring insecticides are known as pyrethrums. A synonym for the naturally occurring pyrethrums is line 15- pyrethrin and synthetic analogues of pyrethrums are known as pyrethroids. In fact, the human mite infestation known as scabies (Sarcoptes scabiei) is treated with a topical pyrethrum cream. We suspect that the bees of commercial bee line 20- colonies which are fed mono-crops are nutritionally deficient. In particular, we postulate that the problem is a diet deficient in anti-mite toxins: pyrethrums, and possibly other nutrients which are inherent in such plants. without, at least, intermittent feeding on line 25- the pyrethrum producing plants, bee colonies are susceptible to mite infestations which can become fatal either directly or due to a secondary infection of immunocompromised or nutritionally deficient bees. This secondary infection can be viral, bacterial or line 30- fungal and may be due to one or more pathogens. In addition, immunocompromised or nutritionally deficient bees may be further weakened when commercially produced insecticides are introduced into their hives by bee keepers in an effort to fight line 35- mite infestation. We further postulate that the proper dosage necessary to prevent mite infestation may be better left to the bees, who may seek out or avoid pyrethrum containing plants depending on the amount necessary to defend against mites and the line 40- amount already consumed by the bees, which in higher doses could be potentially toxic to them. This hypothesis can best be tested by a trial wherein a small number of commercial honey bee colonies are offered a number of pyrethrum line 45- producing plants, as well as a typical bee food source such as clover, while controls are offered only the clover. Mites could then be introduced to each hive with note made as to the choice of the bees, and the effects of the mite parasites on the experimental line 50 - colonies versus control colonies. It might be beneficial to test wild-type honey bee colonies in this manner as well, in case there could be some genetic difference between them that affects the bees’ preferences for pyrethrum producing flowers. The main purpose of the fourth paragraph (lines 42-50) is to

    Honey bees are hosts to the pathogenic large ectoparasitic mite Varroa destructor (Varroa mites). These mites feed on bee hemolymph (blood) and can kill bees directly or by increasing their susceptibility line 5- to secondary infection with fungi, bacteria or viruses. Little is known about the natural defenses that keepthe mite infections under control. Pyrethrums are a group of flowering plants which include Chrysanthemum coccineum, Chrysanthemum line 10- cinerariifolium, Chrysanthemum marschalli, and related species. These plants produce potent insecticides with anti-mite activity. The naturally occurring insecticides are known as pyrethrums. A synonym for the naturally occurring pyrethrums is line 15- pyrethrin and synthetic analogues of pyrethrums are known as pyrethroids. In fact, the human mite infestation known as scabies (Sarcoptes scabiei) is treated with a topical pyrethrum cream. We suspect that the bees of commercial bee line 20- colonies which are fed mono-crops are nutritionally deficient. In particular, we postulate that the problem is a diet deficient in anti-mite toxins: pyrethrums, and possibly other nutrients which are inherent in such plants. without, at least, intermittent feeding on line 25- the pyrethrum producing plants, bee colonies are susceptible to mite infestations which can become fatal either directly or due to a secondary infection of immunocompromised or nutritionally deficient bees. This secondary infection can be viral, bacterial or line 30- fungal and may be due to one or more pathogens. In addition, immunocompromised or nutritionally deficient bees may be further weakened when commercially produced insecticides are introduced into their hives by bee keepers in an effort to fight line 35- mite infestation. We further postulate that the proper dosage necessary to prevent mite infestation may be better left to the bees, who may seek out or avoid pyrethrum containing plants depending on the amount necessary to defend against mites and the line 40- amount already consumed by the bees, which in higher doses could be potentially toxic to them. This hypothesis can best be tested by a trial wherein a small number of commercial honey bee colonies are offered a number of pyrethrum line 45- producing plants, as well as a typical bee food source such as clover, while controls are offered only the clover. Mites could then be introduced to each hive with note made as to the choice of the bees, and the effects of the mite parasites on the experimental line 50 - colonies versus control colonies. It might be beneficial to test wild-type honey bee colonies in this manner as well, in case there could be some genetic difference between them that affects the bees’ preferences for pyrethrum producing flowers. An unstated assumption made by the authors about clover is that the plants

    Honey bees are hosts to the pathogenic large ectoparasitic mite Varroa destructor (Varroa mites). These mites feed on bee hemolymph (blood) and can kill bees directly or by increasing their susceptibility line 5- to secondary infection with fungi, bacteria or viruses. Little is known about the natural defenses that keepthe mite infections under control. Pyrethrums are a group of flowering plants which include Chrysanthemum coccineum, Chrysanthemum line 10- cinerariifolium, Chrysanthemum marschalli, and related species. These plants produce potent insecticides with anti-mite activity. The naturally occurring insecticides are known as pyrethrums. A synonym for the naturally occurring pyrethrums is line 15- pyrethrin and synthetic analogues of pyrethrums are known as pyrethroids. In fact, the human mite infestation known as scabies (Sarcoptes scabiei) is treated with a topical pyrethrum cream. We suspect that the bees of commercial bee line 20- colonies which are fed mono-crops are nutritionally deficient. In particular, we postulate that the problem is a diet deficient in anti-mite toxins: pyrethrums, and possibly other nutrients which are inherent in such plants. without, at least, intermittent feeding on line 25- the pyrethrum producing plants, bee colonies are susceptible to mite infestations which can become fatal either directly or due to a secondary infection of immunocompromised or nutritionally deficient bees. This secondary infection can be viral, bacterial or line 30- fungal and may be due to one or more pathogens. In addition, immunocompromised or nutritionally deficient bees may be further weakened when commercially produced insecticides are introduced into their hives by bee keepers in an effort to fight line 35- mite infestation. We further postulate that the proper dosage necessary to prevent mite infestation may be better left to the bees, who may seek out or avoid pyrethrum containing plants depending on the amount necessary to defend against mites and the line 40- amount already consumed by the bees, which in higher doses could be potentially toxic to them. This hypothesis can best be tested by a trial wherein a small number of commercial honey bee colonies are offered a number of pyrethrum line 45- producing plants, as well as a typical bee food source such as clover, while controls are offered only the clover. Mites could then be introduced to each hive with note made as to the choice of the bees, and the effects of the mite parasites on the experimental line 50 - colonies versus control colonies. It might be beneficial to test wild-type honey bee colonies in this manner as well, in case there could be some genetic difference between them that affects the bees’ preferences for pyrethrum producing flowers. Based on data in the table, in what percent of colonies with colony collapse disorder were the honeybees infected by all four pathogens?

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