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.
Answer:
a. Ligase
b. Ligase (
it's repeated)
Explanation:
DNA synthesis begins, therefore, by synthesizing a short segment of RNA called a primer, which primer is synthesized by an enzyme called Primasa. Primasa is an RNA polymerase that uses DNA as a template. All fragments of Okazaki begin with a Primer. Subsequently, the DNA polymerase III Holoenzyme performs the synthesis of the corresponding DNA fragment until it reaches the next primer. At that time, DNA polymerase Ia replaces the DNA polymerase Holoenzyme III. The DNA polymerase I is responsible for removing the RNA primer through its 5'P-3'OH exonueotic activity and at the same time fills the hole by synthesizing DNA.
Finally, the two Okazaki fragments have to be joined, it is necessary to link the 3'OH end of a fragment with the 5'P of the next fragment. This work of sealing and joining the successive fragments is done by Ligase.
Answer:
1: Burning of fossil fuel
2: Deforestation
3: Waste disposal in landfills
Explanation:
Burning of fossil fuel is the one of the primary cause of increased level of carbon dioxide in air. Deforestation refers to uncontrolled cutting down of trees which in turn increases the level of carbon dioxide in air. Plants are the natural resources that remove the carbon dioxide from air through the process of photosynthesis. Waste disposals in landfills emits methane which is one of the greenhouse gas.
