Light reactions of photosynthesis are carried out by four major protein complexes: Photosystem I (PSI), photosystem II (PSII), the cytochrome b6f complex and ATP synthase. The following are certain statements on PSII:

a. Red light absorbed by photosystem II (PSII) produces a strong oxidant and a weak reductant.

b. Far-red light absorbed by photosystem II (PSI) produces a weak oxidant and a strong reductant.

c. The strong oxidant generated by PSII oxidizes water,

d. The strong reductant generated by PSII oxidizes water

Which one of the following combinations of the above statements is correct?

#Question id: 24553

#Unit 9. Diversity of Life Forms

#Question id: 29101

#Unit 8. Inheritance Biology

A cross between two yellow heterozygous mice produces an initial genotypic ratio of 1/4 YY, 1/2 Yy, and 1/4 yy, the F1 progeny showing lethality in their ratio, if F1 yellow heterozygous mate with nonyellow mice what will be the ratio in F2 generation?

#Question id: 10797

#Unit 6. System Physiology – Plant

The colored pigments of plants are of two principal types: carotenoids and flavonoids. Given below some statements of about these pigments;

 a) Anthocyanins are colored flavonoids that attract animals

b) Flavonoids are phenolic compounds that include a wide range of colored substances

c) Carotenoids are coloured terpenoid compounds that also serve as accessory pigments in photosynthesis

d) most widespread group of pigmented carotenoids is the anthocyanins, these are glycosides that have sugars. Without their sugars, anthocyanins are known as anthocyanidins

Which of the following is incorrect statements of these pigments;

#Question id: 14690

#Unit 13. Methods in Biology

#Question id: 1935

#Unit 4. Cell Communication and Cell Signaling

Evidence for immune surveillance of tumors comes from a substantially increased incidence of certain cancers in patients with: