Answer: Mercury has been well known as an environmental pollutant for several decades. As early as the 1950's it was established that emissions of mercury to the environment could have serious effects on human health. These early studies demonstrated that fish and other wildlife from various ecosystems commonly attain mercury levels of toxicological concern when directly affected by mercury-containing emissions from human-related activities. Human health concerns arise when fish and wildlife from these ecosystems are consumed by humans.
During the past decade, a new trend has emerged with regard to mercury pollution. Investigations initiated in the late 1980's in the northern-tier states of the U.S., Canada, and Nordic countries found that fish, mainly from nutrient-poor lakes and often in very remote areas, commonly have high levels of mercury. More recent fish sampling surveys in other regions of the U.S. have shown widespread mercury contamination in streams, wet-lands, reservoirs, and lakes. To date, 33 states have issued fish consumption advisories because of mercury contamination.
These continental to global scale occurrences of mercury contamination cannot be linked to individual emissions of mercury, but instead are due to widespread air pollution. When scientists measure mercury levels in air and surface water, however, the observed levels are extraordinarily low.
Explanation:
Management because it is holding back how many can be sold.
Answer: Both are always edible.
Explanation:
Mushroom and flowers are use as food and are edible.
Mushroom are succulent and are used as food. They contain low calories, low carbohydrates and are rich in important nutrients like vitamin D, selenium, fibre, potassium,niacin and ribloflavin.
Flowers like marigold, alliums are rich in vitamin C and contain antioxidants that help reduce cholesterol and boost our health.
Answer:
The correct answer will be option-pollen.
Explanation:
The pollen are the male gametophyte which is produced in the seed plants.
The pollen produce male gametes after entering the female gametophyte. The male gametes fuse with the egg cell and form the embryo inside ovary which matures and forms seeds. The vascular seed plants lack these pollen but instead produces male gametes in gametangia which are replaced by the pollen in the seed plants.
Thus, option-pollen is the correct answer.
Answer:
Option A. they less severely affect the phenotype, so that individuals can reproduce and transmit them
Explanation:
Polymorphism is the genetic variation found within a population, which favors the process of natural selection. It prefer successful traits in population.
While, mutation is the alteration of DNA sequence of an organism. Mutation can cause loss of traits in the population.
