托福聽(tīng)力涉及不少知識(shí)，出國(guó)留學(xué)網(wǎng)托福欄目小編整理了相關(guān)的資料，希望可以幫助考生度過(guò)考試的難關(guān)，下面是小編搜集的托福聽(tīng)力背景知識(shí)：紅光和遠(yuǎn)紅光的相關(guān)資訊，歡迎參考!
托福聽(tīng)力背景知識(shí)：紅光和遠(yuǎn)紅光
Introduction：
Red and Far-red
光環(huán)境是植物生長(zhǎng)發(fā)育不可缺少的重要物理環(huán)境因素之一,通過(guò)光質(zhì)調(diào)節(jié),控制植株形態(tài)建成是設(shè)施栽培領(lǐng)域的一項(xiàng)重要技術(shù)。紅光和遠(yuǎn)紅光的吸收比率對(duì)植物的生長(zhǎng)有重要影響。
Background information：
Light isan important environmental factor in most ecosystems. Photosynthetic organismsin particular must sense and respond to light cues to optimize their growth andmetabolism. The quantity, direction and spectral make-up (the color or'quality') of the light sensed by an organism conveys information regarding theabiotic and biotic environment and can be used to control adaptive responses.One superfamily of photosensory receptors comprises the phytochromes ('plantcolor'), which absorb in the red/far-red part of the spectrum. These receptorswere first discovered in plants in the 1950s, but have more recently beenidentified in a broad spectrum of eukaryotic and prokaryotic phyla.
Far-redlight is light at the extreme red end of the visible spectrum, between red andinfra- red light. Usually regarded as the region between 710 and 850 nmwavelength, it is dimly visible to some eyes. It is largely reflected ortransmitted byplantsbecause of the absorbance spectrum of chlorophyll, and itis perceived by the plant photoreceptor phytochrome. However, some organismscan use it as a source of energy in photosynthesis. Far-red light also is usedfor vision by certain organisms such as some species of deep-sea fishes.
Knowledge points：
1. 生態(tài)系統(tǒng)中光是十分重要的一個(gè)元素。特別是光合生物必須感知和響應(yīng)光來(lái)優(yōu)化它們的生長(zhǎng)和代謝。
2. 光感接收器中間的一部分由光敏色素組成,它吸收光譜中的紅光和遠(yuǎn)紅光。
3. 遠(yuǎn)紅光大部分都被植物反射掉了。然而,有些植物在光合作用中用遠(yuǎn)紅光作為能量來(lái)源。一些深海魚(yú)類(lèi)用遠(yuǎn)紅光來(lái)辨別視野。
Vocabulary prediction：
Infrared 紅外線
Photoreceptor 感光器
Ratio 比率
Simulate 模擬
Test Point – TPO28L3
Plants are also able to distinguish betweenspecific wavelengths of light that the human eye cannot even see! Specificallythere’s a wavelength called far-red. Although why they call it far- red ... Imean, it is not red at all. It lies in the infrared range of the spectrum. Wecan’t see it, but plants can sense it as a different wavelength.
OK. Now I need to mention another thingabout photosynthesis. I didn’t explain how different wavelengths of light affectphotosynthesis. When a plant absorbs light for performing photosynthesis, itonly absorbs some wavelengths of light and reflects others.
Plants absorb most of the red light thathits them, but plants only absorb some of the far-red light that hits them.They reflect the rest. Remember this, because it’s going to be relevant in anexperiment I want to discuss.
This fascinating experiment showed thatplants not only detect and react to specific wavelengths of light, plants canalso detect and react to changes in the ratio of one wavelength to another.This experiment was called the Pampas experiment.
Knowledge points
1.遠(yuǎn)紅外線并不是紅色的。只是它位于光譜中紅外線的頻譜。人類(lèi)不能看見(jiàn),但是植物能夠感知它。
2.當(dāng)植物吸收光線用作光合作用,植物僅僅吸收一些特定波長(zhǎng)的光線,反射另一些。
3.植物吸收大部分的投射到的紅光,但是植物只吸收一部分遠(yuǎn)紅光。
4.植物也可以就不同波長(zhǎng)的比率做反應(yīng)。
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