The earth's atmosphere consists mainly of nitrogen and oxygen with smaller proportions of other gases such as carbon dioxide. The amount of carbon dioxide in the atmosphere is maintained through a balance between processes such as photosynthesis, respiration and combustion. However this balance is being affected by human activities which are polluting the atmosphere.
The proportion of these gases in the atmosphere is as follows: nitrogen is the most abundant at 78%, oxygen is next at 21%, while others include carbon dioxide at 0.037% and argon at 0.9 % .
Answer:
The answer is double helix.
Explanation:
In its natural state, each DNA molecule is actually composed of two single strands held together along their length with hydrogen bonds between the bases. Watson and Crick proposed that the DNA is made up of two strands that are twisted around each other to form a right-handed helix, called a double helix.
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Explanation:
Winds are caused by low and high pressure zones, mainly due to temperature differences of atmospheric air in different regions. Air moves from high to low-pressure zones causing winds.
Local winds, as the name suggests, are winds due to regional temperature differences. An example is sea breeze caused by temperature differences over land and sea in the region.
Global winds, on the other hand, are caused by large pressure systems across the planet. These are mainly caused by differences in how the sunlight ‘hits’ the planet at different latitudes – due to earth’s spherical nature- causing differential heating of the earth. These winds travel great distances causing trade winds.
Explanation:
<em>Characteristics</em><em> </em><em>are</em><em> </em><em>as</em><em> </em><em>under:</em>
<em>1</em><em>.</em><em> </em><em>Living</em><em> </em><em>things</em><em> </em><em>respire.</em><em>.</em><em>.</em>
<em>2.</em><em> </em><em>Living </em><em>things</em><em> </em><em>can</em><em> </em><em>move</em><em>.</em><em>.</em>
<em>3</em><em>.</em><em> </em><em> </em><em>M</em><em>a</em><em>de </em><em>uo</em><em> </em><em>of</em><em> </em><em>cells</em><em>.</em><em>.</em>
<em>4</em><em>.</em><em> </em><em>Can</em><em> </em><em>Reproduce</em><em>.</em><em>.</em>
<em>5</em><em>.</em><em> </em><em>They</em><em> </em><em>carry</em><em> out</em><em> </em><em>various</em><em> </em><em>Life</em><em> </em><em>pr</em><em>o</em><em>cesses.</em><em>.</em><em>.</em>