Which structure on the sperm propels in toward the egg

Tail

Explanation: Sperms usually consists of two regions.One is head and other one is tail. The tail part of the sperm propels it towards the egg and helps it to burrow through the egg coat.

The head region of the sperm contain condensed form of haploid nucleus. The DNA is packed extremely tight inside the head.

flagellum is the answer! Hope this helps

poor water quality affects most estuarine organisms, including commercially important fish and shellfish. the pollutants that have the greatest impact on the health of estuaries include toxic substances like chemicals and heavy metals, nutrient pollution (or eutrophication), and pathogens such as bacteria or viruses.