Plant Physiology 36) Plant trichomes can function in A) Physical defenses agains
ID: 268305 • Letter: P
Question
Plant Physiology
36) Plant trichomes can function in A) Physical defenses against herbivores B) Chemical defenses against herbivores C) Either A or B, separately A volatile secondary metabolite that deters herbivory would most likely be concentrated in A) leaf palisade cells B) phloem cells C) glandular trichomes Provide two or more characteristics that can be used to define secondary metabolites. (2 pts) D) Either A or B, separately or together E) None of the above 37) D) brightly colored flowers E) all cells equally 38) 39) The "modern era" of medicine, when people started isolating and characterizing compounds with medicinal benefits from plants A) initiated with the evolution of Homo sapiens B) was recorded in the earliest writings and thus initiated more than 4000 years ago C) started toward the end of the Roman Empire, but this knowledge was lost for about 1000 years D) started about 200 years ago E) started about 100 years ago 40) More people in the world now turn to pharmaceutical medicines rather than plant-based herbal medicines. FALSE 41) Capsaicin is the compound that makes hot peppers hot, and evolved to provide defense against A) mammals B) birds C) insects D) all of the above B) A and Conly F) A and B only 42) During a hypersensitive response A) Chewing insects damage tissues and promote the synthesis and transport of systemin. death C) Reactive oxygen species help contain the pathogen and promote other defense responses D) All of the above E) B and C onlyExplanation / Answer
Ans. 36. Correct option is (D). Plant trichomes are short outgrowths or hair like structure called as appendages. It can be prickles that are epidermal outgrowths and hair which can be uni or multicellular, branched or unbranched. These trichomes can be used as chemical means of defense against herbivores, for example, plant Urtica has stinging hairs that releases histamines. Trichomes on bean leaves captures the insect by piercing their feet, this is a physical means of protecting itself from herbivores. Also plant gland excudes sticky substances that makes the insect stick to the plant and hence plant uses glandular trichomes as chemical method of protection. Both chemical and physical means of barrier can be present and functional in plants at once.
Ans. 37. Correct option is (C). Glandular trichomes are known to secrete flavonoids, alkaloids, terpenoids, which acts as a repellent or poisonous while trapping or killing the insect.
Ans. 38. Secondary metabolites can be defined if found to have these characters:
1. These are secreted by glandular trichomes and can act as a chemical method of defense system for plants against herbivory.
2. It can be inactive or can be induced by the attack of herbivores.
3. It doesnot affect the normal growth of the plant but can affect the appetizing or pleasant nature of the plant.
Ans. 39. Correct option os (C). The recordings about use of plants as medicines were found from the Sumerian clay near Nagpur which was dated more than 5000 years ago and it had a list of recipes of drugs originated from plants. Likewise, Chinese book Pen T Sao dates back to 2500 BC having details of more than 365 drugs. Also Vedas from India shows the writings of use of various plants parts for their medicinal value. Charles the Great, in his book Capitularis reported use of more than 100 plants for their medicinal use (742-814 AD).
Ans. 40. The answer is TRUE because plant based medicines are natural hence chemists must identify, isolate and purify these plant based chemicals which can act as natural medicine instead of synthesized chemicals.
Ans. 41. Correct option is (E). Capsaicin is produced when either mammals who have teeth and insects who have piercing power chews chilli pepper. But birds dont have teeth so they cannot chew the seeds of pepper hence let the seeds to disperse and help in reproduction of plants. But mammals and insects can chew the seeds and not let the plant produce new plants from their seeds thus this is a protection mechanism of plants of saving their offsprings from predators. The hotness of chilli gives an unpleasant taste to mammals and insects so that they donot eat anymore chiilli and the seeds can be protected.
Ans. 42. Correect option is (D). When plant leaves are chewed by caterpillars or insects Systemins are produced which are small peptides of 18 amino acids. The processed peptide is transported to the apoplast where interaction with membrane receptor occurs and leads to early or late defense responses in plants.
Also in tomoato plants affected by insects are shown to produce prosystemin which activates the accumulation of Proteinase inhibitors that might kill the insect by inhibiting the digestive enzymes in the insect's gut.
Herbivory by vhewing insects releases Hydrogen peroxide which acts as a source of oxidative burst which too induces systemin promote various plant defenses.