Zoological parks and botanical gardens are examples of: MCQ with Answer and Explanation

Explanation:
Xenogamy is the type of cross-pollination where pollen grains are transferred from the anther of one plant to the stigma of a genetically different plant. This promotes genetic diversity. Autogamy is self-pollination within the same flower. Geitonogamy is the transfer of pollen between different flowers on the same plant (functionally cross-pollination but genetically self-pollination). Cleistogamy is closed, self-pollinating flowers.

Explanation:
Phytoplankton, including cyanobacteria, diatoms, and dinoflagellates, are microscopic photosynthetic organisms that drift in oceans and freshwaters. They are primary producers responsible for about half of global oxygen production. Brown, red, and green macroalgae also contribute but phytoplankton are the primary oxygen producers.

Explanation:
Schwann cells wrap around axons in the PNS to form myelin sheaths. Oligodendrocytes myelinate axons in the CNS. Astrocytes support neurons, microglia are immune cells.