Consider statements about human diseases: 1. Cholera is caused by a bacterium. 2. Polio is caused by a virus. 3. Ringworm is caused by a fungus. Which are correct? MCQ with Answer and Explanation

Explanation:
Pollination is the mechanism of transferring pollen grains from the anther to the stigma of a flower. After fertilization, the ovule develops into a seed and the ovary into a fruit. Double fertilization, involving syngamy and triple fusion, is a unique characteristic of angiosperms, not gymnosperms. Therefore, statements 1 and 3 are correct.

Explanation:
The Red Data Book (or Red List) is a comprehensive document maintained by the International Union for Conservation of Nature (IUCN). It records the global conservation status of plant and animal species. It categorizes species based on their risk of extinction, using categories like Extinct, Extinct in the Wild, Critically Endangered, Endangered, Vulnerable, Near Threatened, and Least Concern. It serves as a critical tool for identifying species that require urgent conservation efforts.

Explanation:
The sinoatrial node spontaneously depolarizes, setting the rhythm of the heart. The reason correctly explains its role as pacemaker.