Questions
1. an example of a plant’s use of chemicals in its reproductive process
Select
A. Adapted to life in the hot, desert inland, spinifex has developed tightly rolled leaves which reduce the effects of drought stress. The hairs, or trichomes, which are found on the inner surface of the rolled-up spinifex leaf are believed to assist in minimising water loss. Many plants, such as the sunflower, have hairy leaves which are rough to the touch. When the plant is bitten by a grazing animal, the sensation is unpleasant on the tongue and the animal normally moves on to find more palatable food. B. In other plants of the same family, the sacs contain a natural adhesive and the unsuspecting insect landing on such a leaf and rupturing a trichome sac is held onto the plant, unable to depart. In the leaves of the nettle plant these trichomes resemble miniature hypodermic syringes. An irritant chemical is stored at the base of the ‘syringe’. If an animal touches it, a shot of the chemical is discharged through the ‘needle’ and into the skin of the animal. The irritation the chemical causes is a deterrent against future threat. C. In agriculture, allelopathy has been identified particularly with weeds, which compete with desired crop or pasture species, such as wheat, oats and grass, for environmental chemicals which may poison a neighbouring plant. On the whole, weeds are far more physically and chemically aggressive than crop and pasture species. As an example, recent research on the common thorn apple, has found that two powerful chemicals are released from the seed during the early stages of germination. In fact, it is necessary for the chemicals to be released from the seed coat so that the seed can germinate. Once released, the chemicals then provide a barrier that inhibits the growth of any potential plant competitor near the thorn apple seedling. D. Enhancing allelopathic activity in crop and pasture plants could reduce this enormous bill. Developing and harvesting natural herbicides might also offer real advantages in addressing environmental concerns about the over-use of synthetic chemicals currently used in crop protection.
2. how some plants use a kind of glue to discourage attack
Select
A. Adapted to life in the hot, desert inland, spinifex has developed tightly rolled leaves which reduce the effects of drought stress. The hairs, or trichomes, which are found on the inner surface of the rolled-up spinifex leaf are believed to assist in minimising water loss. Many plants, such as the sunflower, have hairy leaves which are rough to the touch. When the plant is bitten by a grazing animal, the sensation is unpleasant on the tongue and the animal normally moves on to find more palatable food. B. In other plants of the same family, the sacs contain a natural adhesive and the unsuspecting insect landing on such a leaf and rupturing a trichome sac is held onto the plant, unable to depart. In the leaves of the nettle plant these trichomes resemble miniature hypodermic syringes. An irritant chemical is stored at the base of the ‘syringe’. If an animal touches it, a shot of the chemical is discharged through the ‘needle’ and into the skin of the animal. The irritation the chemical causes is a deterrent against future threat. C. In agriculture, allelopathy has been identified particularly with weeds, which compete with desired crop or pasture species, such as wheat, oats and grass, for environmental chemicals which may poison a neighbouring plant. On the whole, weeds are far more physically and chemically aggressive than crop and pasture species. As an example, recent research on the common thorn apple, has found that two powerful chemicals are released from the seed during the early stages of germination. In fact, it is necessary for the chemicals to be released from the seed coat so that the seed can germinate. Once released, the chemicals then provide a barrier that inhibits the growth of any potential plant competitor near the thorn apple seedling. D. Enhancing allelopathic activity in crop and pasture plants could reduce this enormous bill. Developing and harvesting natural herbicides might also offer real advantages in addressing environmental concerns about the over-use of synthetic chemicals currently used in crop protection.
3. examples of non-chemical methods of defence in plants
Select
A. Adapted to life in the hot, desert inland, spinifex has developed tightly rolled leaves which reduce the effects of drought stress. The hairs, or trichomes, which are found on the inner surface of the rolled-up spinifex leaf are believed to assist in minimising water loss. Many plants, such as the sunflower, have hairy leaves which are rough to the touch. When the plant is bitten by a grazing animal, the sensation is unpleasant on the tongue and the animal normally moves on to find more palatable food. B. In other plants of the same family, the sacs contain a natural adhesive and the unsuspecting insect landing on such a leaf and rupturing a trichome sac is held onto the plant, unable to depart. In the leaves of the nettle plant these trichomes resemble miniature hypodermic syringes. An irritant chemical is stored at the base of the ‘syringe’. If an animal touches it, a shot of the chemical is discharged through the ‘needle’ and into the skin of the animal. The irritation the chemical causes is a deterrent against future threat. C. In agriculture, allelopathy has been identified particularly with weeds, which compete with desired crop or pasture species, such as wheat, oats and grass, for environmental chemicals which may poison a neighbouring plant. On the whole, weeds are far more physically and chemically aggressive than crop and pasture species. As an example, recent research on the common thorn apple, has found that two powerful chemicals are released from the seed during the early stages of germination. In fact, it is necessary for the chemicals to be released from the seed coat so that the seed can germinate. Once released, the chemicals then provide a barrier that inhibits the growth of any potential plant competitor near the thorn apple seedling. D. Enhancing allelopathic activity in crop and pasture plants could reduce this enormous bill. Developing and harvesting natural herbicides might also offer real advantages in addressing environmental concerns about the over-use of synthetic chemicals currently used in crop protection.
4. descriptions of how plants use chemicals to discourage predators
Select
A. Adapted to life in the hot, desert inland, spinifex has developed tightly rolled leaves which reduce the effects of drought stress. The hairs, or trichomes, which are found on the inner surface of the rolled-up spinifex leaf are believed to assist in minimising water loss. Many plants, such as the sunflower, have hairy leaves which are rough to the touch. When the plant is bitten by a grazing animal, the sensation is unpleasant on the tongue and the animal normally moves on to find more palatable food. B. In other plants of the same family, the sacs contain a natural adhesive and the unsuspecting insect landing on such a leaf and rupturing a trichome sac is held onto the plant, unable to depart. In the leaves of the nettle plant these trichomes resemble miniature hypodermic syringes. An irritant chemical is stored at the base of the ‘syringe’. If an animal touches it, a shot of the chemical is discharged through the ‘needle’ and into the skin of the animal. The irritation the chemical causes is a deterrent against future threat. C. In agriculture, allelopathy has been identified particularly with weeds, which compete with desired crop or pasture species, such as wheat, oats and grass, for environmental chemicals which may poison a neighbouring plant. On the whole, weeds are far more physically and chemically aggressive than crop and pasture species. As an example, recent research on the common thorn apple, has found that two powerful chemicals are released from the seed during the early stages of germination. In fact, it is necessary for the chemicals to be released from the seed coat so that the seed can germinate. Once released, the chemicals then provide a barrier that inhibits the growth of any potential plant competitor near the thorn apple seedling. D. Enhancing allelopathic activity in crop and pasture plants could reduce this enormous bill. Developing and harvesting natural herbicides might also offer real advantages in addressing environmental concerns about the over-use of synthetic chemicals currently used in crop protection.
5. benefits of using plant-based chemicals to control weeds in agricultural areas
Select
A. Adapted to life in the hot, desert inland, spinifex has developed tightly rolled leaves which reduce the effects of drought stress. The hairs, or trichomes, which are found on the inner surface of the rolled-up spinifex leaf are believed to assist in minimising water loss. Many plants, such as the sunflower, have hairy leaves which are rough to the touch. When the plant is bitten by a grazing animal, the sensation is unpleasant on the tongue and the animal normally moves on to find more palatable food. B. In other plants of the same family, the sacs contain a natural adhesive and the unsuspecting insect landing on such a leaf and rupturing a trichome sac is held onto the plant, unable to depart. In the leaves of the nettle plant these trichomes resemble miniature hypodermic syringes. An irritant chemical is stored at the base of the ‘syringe’. If an animal touches it, a shot of the chemical is discharged through the ‘needle’ and into the skin of the animal. The irritation the chemical causes is a deterrent against future threat. C. In agriculture, allelopathy has been identified particularly with weeds, which compete with desired crop or pasture species, such as wheat, oats and grass, for environmental chemicals which may poison a neighbouring plant. On the whole, weeds are far more physically and chemically aggressive than crop and pasture species. As an example, recent research on the common thorn apple, has found that two powerful chemicals are released from the seed during the early stages of germination. In fact, it is necessary for the chemicals to be released from the seed coat so that the seed can germinate. Once released, the chemicals then provide a barrier that inhibits the growth of any potential plant competitor near the thorn apple seedling. D. Enhancing allelopathic activity in crop and pasture plants could reduce this enormous bill. Developing and harvesting natural herbicides might also offer real advantages in addressing environmental concerns about the over-use of synthetic chemicals currently used in crop protection.
6. a description of the characteristics of allelopathic chemicals
Select
A. Adapted to life in the hot, desert inland, spinifex has developed tightly rolled leaves which reduce the effects of drought stress. The hairs, or trichomes, which are found on the inner surface of the rolled-up spinifex leaf are believed to assist in minimising water loss. Many plants, such as the sunflower, have hairy leaves which are rough to the touch. When the plant is bitten by a grazing animal, the sensation is unpleasant on the tongue and the animal normally moves on to find more palatable food. B. In other plants of the same family, the sacs contain a natural adhesive and the unsuspecting insect landing on such a leaf and rupturing a trichome sac is held onto the plant, unable to depart. In the leaves of the nettle plant these trichomes resemble miniature hypodermic syringes. An irritant chemical is stored at the base of the ‘syringe’. If an animal touches it, a shot of the chemical is discharged through the ‘needle’ and into the skin of the animal. The irritation the chemical causes is a deterrent against future threat. C. In agriculture, allelopathy has been identified particularly with weeds, which compete with desired crop or pasture species, such as wheat, oats and grass, for environmental chemicals which may poison a neighbouring plant. On the whole, weeds are far more physically and chemically aggressive than crop and pasture species. As an example, recent research on the common thorn apple, has found that two powerful chemicals are released from the seed during the early stages of germination. In fact, it is necessary for the chemicals to be released from the seed coat so that the seed can germinate. Once released, the chemicals then provide a barrier that inhibits the growth of any potential plant competitor near the thorn apple seedling. D. Enhancing allelopathic activity in crop and pasture plants could reduce this enormous bill. Developing and harvesting natural herbicides might also offer real advantages in addressing environmental concerns about the over-use of synthetic chemicals currently used in crop protection.
7. an example of a physical characteristic that helps one plant conserve water
Select
A. Adapted to life in the hot, desert inland, spinifex has developed tightly rolled leaves which reduce the effects of drought stress. The hairs, or trichomes, which are found on the inner surface of the rolled-up spinifex leaf are believed to assist in minimising water loss. Many plants, such as the sunflower, have hairy leaves which are rough to the touch. When the plant is bitten by a grazing animal, the sensation is unpleasant on the tongue and the animal normally moves on to find more palatable food. B. In other plants of the same family, the sacs contain a natural adhesive and the unsuspecting insect landing on such a leaf and rupturing a trichome sac is held onto the plant, unable to depart. In the leaves of the nettle plant these trichomes resemble miniature hypodermic syringes. An irritant chemical is stored at the base of the ‘syringe’. If an animal touches it, a shot of the chemical is discharged through the ‘needle’ and into the skin of the animal. The irritation the chemical causes is a deterrent against future threat. C. In agriculture, allelopathy has been identified particularly with weeds, which compete with desired crop or pasture species, such as wheat, oats and grass, for environmental chemicals which may poison a neighbouring plant. On the whole, weeds are far more physically and chemically aggressive than crop and pasture species. As an example, recent research on the common thorn apple, has found that two powerful chemicals are released from the seed during the early stages of germination. In fact, it is necessary for the chemicals to be released from the seed coat so that the seed can germinate. Once released, the chemicals then provide a barrier that inhibits the growth of any potential plant competitor near the thorn apple seedling. D. Enhancing allelopathic activity in crop and pasture plants could reduce this enormous bill. Developing and harvesting natural herbicides might also offer real advantages in addressing environmental concerns about the over-use of synthetic chemicals currently used in crop protection.
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