Answer:
According to the “hygiene hypothesis,” the problem with extremely clean environments is that they fail to provide the necessary exposure to germs required to “educate” the immune system so it can learn to launch its defense responses to infectious organisms. Instead, its defense responses end up being so inadequate that they actually contribute to the development of asthma.
Explanation:
While both carbohydrates and lipids are made up of carbon, hydrogen and oxygen there are several differences:
1. Carbohydrates are chains of 2 or more carbon atoms. These can be very lengthy (like long cellulose chains of glucose units). They have many polar OH groups (e.g. glucose - C6H6O6). Most carbohydrates are hydrophilic and are soluble in water because of their polar OH groups. They are not necessarily sugars nor are they necessarily sweet. They are also important components of DNA, RNA and ATP.
2. Lipids are more diverse in their chemistry. They generally have a polar region at one end (this end attracts water) and a large non polar hydrocarbon region that repels water. Lipids don't dissolve in water and instead clump together with their hydrocarbon regions on the interior. Lipids include oils, fatty acids, waxes, steroids and hormones.
Answer:
Shelter and settlement forms in hot humid, hot dry and cold climatic zones have been described. Performance efficiency of passive climate control systems of vernacular buildings have been analysed and their relevance to contemporary design and planning of housing and new towns in selected regions are examined. A comment is also made on the role of climate in the interaction between settlements and their hinterland.
Explanation:
