Bemisia tabaci, also known as silverleaf whiteflies, are agricultural pests that pose a threat to a wide-range of crops. Tomato plants are particularly susceptible to the flies. A team of researchers led by Dr. Xiao-Ping Yu found when silverleaf whiteflies attack tomato plants, the plants release an odor which indicates to nearby tomato plants that the plant is under attack from a fungus or bacteria. Dr. Yu and his colleagues hypothesize that this warning suppresses the plants' ability to resist the insects, since they are focusing on protecting themselves from pathogens rather than insects. Which finding, if true, would most directly support the researchers' hypothesis?Silverleaf whiteflies are particularly dangerous to plants because they are transmitters of bacterial pathogens.eliminateWhen exposed to silverleaf whiteflies, the likelihood of a tomato plant surviving a growing season decreases by nearly 50%.eliminateIsolated tomato plants prove more resistant to silverleaf whitefly attacks than ones found in groups of tomato plants.eliminateTomato plants thrive more readily in areas with low silverleaf whitefly populations.

Insects can be both useful and harmful to crop plants. Insects such as bees pollinate or cross pollinate flowers. Some insects eat crops and other insects eat the insects that eat crops.Corn borers are insects that eat maize plants. A toxin produced by the bacterium Bacillus thuringiensis kills insects. Scientists grow Bacillus thuringiensis in large containers. The toxin is collected from the containers and is sprayed over maize crops to kill corn borers.A company has developed genetically modified (GM) maize plants. GM maize plants contain a gene from Bacillus thuringiensis. This gene changes the GM maize plants so that they produce the toxin.How did the scientists transfer the gene from Bacillus thuringiensis to maize plants?Genes are added only once the plant is developed by injecting enzymes are used to both remove unwanted and insert desired genes.Genes are added early on in the development process by gene splicing. Enzymes are used to both remove unwanted and insert desired genes.The genes of Bt toxin can only be added to certain plants, by spraying them with the Bt toxin gene.Genes are added only in the late development process by gene splicing. Enzymes are used to both remove and inserted genes.I DON'T KNOWSUBMIT ANSWER

All-Natural Pest PreventionLee Washington1As the weather becomes warmer and people travel outside more often, daring pests creep indoors to explore kitchens and pantries. It is important to know that insects and mice can contribute to the spread of germs and diseases. At the very least, these pests can damage food supplies or cause itchy bug bites. From the largest mice to the tiniest fleas, these creatures can turn a peaceful home into a crawling nightmare!2Many people, however, hesitate to use commercial sprays near children and pets or in places where they store food. The harsh chemicals in these sprays can cause serious injuries if they aren’t used properly. Luckily, there is now another choice for people who want to avoid these dangerous chemicals. The experts at Growing Garden Supply are happy to help you discover all-natural ways of keeping these creatures outdoors, where they belong.3This week, pots of peppermint and lavender plants are on sale. These herbs not only let off fragrant scents, but they also can be used to keep pests out of your home. Place a pot of lavender in the kitchen to ward off mice and use mint as an all-purpose pest remover. The scent of crushed mint leaves is unpleasant for mice, ants, and fleas. Sprinkle a few along the edge of your home to discourage pests from entering. Happily, mint leaves are completely safe for humans to eat. Try some in a cup of tea, or use them to add flavor to baked goods.4After seeing the great results from the mint and lavender plants, why not start an entire garden of plants that are unappealing to pests? Growing Garden Supply has an excellent selection of bitter cucumber seeds and garlic bulbs. Slices of cucumbers and garlic can help chase away ugly roaches and mosquitoes, and the leftovers taste wonderful in summer salads and pasta dishes.5People who are eager for an immediate fix to their pest problems might prefer a liquid spray. Fortunately, we have many plant oils and spray bottles in stock! Some of these essential oils can be combined for an even greater effect. Remember, essential oils cannot be stored in plastic or metal for long periods—the oils will eat away at the container. Instead, check out Growing Garden Supply’s impressive collection of beautiful glass jars, available in a variety of shapes and sizes. This will solve all of your oil storage problems.6Once the house is free of pests, consider natural ways of keeping wildlife from attacking your garden and yard. Choosing the right plants to grow together can be a natural way of keeping hungry caterpillars and rabbits away. Ask our specially trained employees for more helpful suggestions on pest prevention both in and outside the home.Question 1Which best describes the point of view of the author in this passage?ResponsesA The author believes that essential oils are essentially a scam.The author believes that essential oils are essentially a scam.B The author believes that pests can be prevented using all natural methods.The author believes that pests can be prevented using all natural methods.C The author believes that all natural pest prevention is not as effective as chemical preventatives.The author believes that all natural pest prevention is not as effective as chemical preventatives.D The author believes that a mix of chemical and all-natural pest preventatives is most effective for garden care.The author believes that a mix of chemical and all-natural pest preventatives is most effective for garden care.Question 2Which two quotations from the passage best support the idea that all-natural pest preventatives can be effective?ResponsesA Happily, mint leaves are completely safe for humans to eat.Happily, mint leaves are completely safe for humans to eat.B This week, pots of peppermint and lavender plants are on sale.This week, pots of peppermint and lavender plants are on sale.C The scent of crushed mint leaves is unpleasant for mice, ants, and fleas.The scent of crushed mint leaves is unpleasant for mice, ants, and fleas.D People who are eager for an immediate fix to their pest problems might prefer a liquid spray.People who are eager for an immediate fix to their pest problems might prefer a liquid spray.E Place a pot of lavender in the kitchen to ward off mice and use mint as an all-purpose pest remover.

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Which of the following is not a function of the waxy cuticle that coats plant leaves?Prevents water loss from the leafPrevents fungal spore germination on the leafProtects the leaf from infectionAllows water to be absorbed through the leaf2Which of the following statements about chemical defences in plants is not true?Mint produces antibacterial chemicalsCyanide, produced by some plants, is used in medicinesCitronella is a pest repellent released by lemongrassCaffeine has the ability to kill fungi3Which of these is not a mechanical adaptation in plants to deter herbivores?MimicryDrooping leavesPoisonsThorns4Why do passion flower leaves have spots that mimic butterfly eggs?To prevent fungal spores from germinatingTo prevent pathogens from attacking themTo prevent butterflies from laying their eggs on themTo prevent herbivores from eating them