AP BIOLOGY

Detailed explanation-1: -Anther, contains pollen grains but pollen grains are produced in pollen sac. Pollen sac is the structure in seed plants in which pollen is produced. In angiosperms there are usually four pollen sacs in each anther; they contain the microspore mother cells. Therefore, it is the correct answer.

Detailed explanation-2: -In angiosperms, pollen is produced by the anthers of the stamens in flowers.

Detailed explanation-3: -Through the process of meiosis, pollen is formed in the pollen sacs (microsporangia) inside the anthers of a flower. The anther, while it is developing from anther primordium (undifferentiated cells), forms two clusters of cells.

Detailed explanation-4: -Pollen is produced by the anthers of the stamens in flowers in angiosperms. It is generated in the microsporophylls of the microstrobili of gymnosperms (male pollen cones). One or more vegetative cells and a reproductive cell make up pollen.

Detailed explanation-5: -At the two-celled stage, pollen grains are shed from the anther in Angiosperms.