Answer:
The skin is an organ of protection
Explanation:
The primary function of the skin is to act as a barrier. The skin provides protection from: mechanical impacts and pressure, variations in temperature, micro-organisms, radiation and chemicals.
Answer: Atmospheric Nitrogen is unreactive
Explanation:
The atmosphere is made up of about 80% Nitrogen, 16% oxygen, about 4% carbon dioxide, rare gases etc.
However, the 80% Nitrogen is highly unreactive, and needs to be trapped by competent micro organisms known as nitrogen-fixing bacteria in the root nodules of legumes.
Then, it is converted to several forms like nitrites, nitrates (easily absorbed by plants), ammonia and finally escape to the atmosphere again.
This brief illustration explains the NITROGEN CYCLE, and it is the only means by which plants and animals can use the highly unreactive nitrogen
Carbon 14 has a half life of 5,730 years. Scientists measure how much carbon 14 the rock has. For objects older than 50,000 years, scientists will test the age of the things surrounding it.
B) The atria only recieve blood and the Ventricles have to pump the blood
1. is the sun
2. is is waters the plants and help things grow