Answer:
A. sexual reproduction
Explanation:
Sexual reproduction produces a new combination of genes in the offspring that may better enable them to survive changes in the environment and assist in the survival of the species.
Develop diseases because they have little genetic variation.
Answer:
The wechsler intelligence scale for children (WISC) is a good indicator of innate "genetic" ability for children of six to sixteen years old.
Explanation:
Wechsler Intelligence Scale for Children (WISC) is basically a system of testing IQ of children from six to sixteen years old. This testing was created by David Wechsler, who stated that intelligence is a global quality and it should be reflected in children's verbal as well as non-verbal abilities.
This testing system is used by schools for several purposes:
• To evaluate the performance of kids during placement process.
• It is also used to evaluate abilities of dis-abled children or deferentially able children.
• IQ scores from WISC can be used to diagnose the problems of the children such as mental re-tardation or some specific learning dis-ability. It can also be used to determine the problems of the children who face hyperactivity or attention deficiency.
• In addition, the test can also diagnose brain related and neuro-psychological disorder.
Point to remember:
The WISC system is not useful to determine the extreme form of intelligence like IQ below 40 and above 160. Wechsler himself focused on this point many times that test is not adequate for children with IQs of below 70 or above 130. Despite of this fact, people use this test to determine the intelligence of deferentially able children who usually have IQ above 130 that is not very appropriate thing.
<em>Note:</em><em> This answer is very generic based on the statement of the question. If you have some specific options of the questions, please post it again with them or comment. Thank you.</em>
Gram staining
Gram-positive turns pink or red
Gram negative turns dark blue or purple
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: