皮皮学，免费搜题
登录
搜题
【单选题】
执行下列代码后,结果的值是?A.
VOLTS DC +2
B.
VOLTS DC +
C.
50
D.
250
拍照语音搜题，微信中搜索"皮皮学"使用
参考答案：
参考解析：
知识点：
皮皮学刷刷变学霸
举一反三
【多选题】What is the role of carotenoids as accesspry pigments in photosynthesis?
A.
In addition to chlorophylls, thylakoid membranes contain secondary lightabsorbing pigments, or accessory pigments, called carotenoids.
B.
Carotenoids may be yellow, red, or purple. The most important are β-carotene, which is a red-orange isoprenoid, and the yellow carotenoid lutein.
C.
The carotenoids absorb light at wavelengths not absorbed by the chlorophylls and thus are supplementary light receptors.
D.
They also protect downstream components from a highly reactive form of oxygen (singlet oxygen) that is formed when intense light exceeds the system’s capacity to accept electrons.