Normal polarity
Explanation:
Earth's magnetic field used to be twice as strong 1.5 billion years ago as it is today and Earth's temperature other than what the geologists see from the 'normal' pattern. It has been noticed that some volcanic rocks were magnetized in opposite direction to the direction of the local Earth's field. It is clear that the Earth has experienced the normal polarity 1.5 years ago but at that time, the Earth's polarity was poorly understood.
Because of underdeveloped lungs the frog has to breathe through moist skin. Therefore for exchange of gases the skin is thin and moist
Answer:
Dust bowl resulted from extreme drying and loosening of the soil that resulted in soil erosion by wind. Thus, it can be related that poor agricultural practices like over plowing , over grazing and leaving the land barren are human activities that must have contributed to the dust bowl.
Explanation:
- Dust bowl is referred to a period in early twentieth century when the the American and Canadian prairies faced severe dust storms.
- These dust storms resulted from severe drought and failure of practices to prevent soil erosion.
- Several people and livestock died as a result of choking.
- Over plowing, removal of top soil and small grasses exposed the soil to eroding winds and caused the dust storms.
After mining, to reclaim the land, the depression is filled with rocks then the top is filled with loosely graded soil. Introduction of early succession plants is important before big trees can grow. The early succession plants help in the breaking down of the rocks into soil hence making the topsoil deeper to support trees.
Answer:
Peptide bonds and Amino Acids
Explanation:
Primary structure. The primary structure of a protein refers to the sequence of amino acids in the polypeptide chain. The primary structure is held together by peptide bonds that are made during the process of protein biosynthesis.