Answer:
(a)-Rills, and arroyos or gullies develop mainly during prolonged droughts.
Explanation:
Soil erosion is the process of erosion, transport and sedimentation of soil, subsoils and rocks as an effect of the action of erosive agents such as water, winds and living things. The process of disintegration of rock particles (called sediments) is caused by the action of weathering (a set of chemical, physical and biological processes that cause soil and rock wear).
About soil erosion, we can confirm that the following information is true:
- Grasses and other vegetation, windbreaks, and contour cropping will help reduce soil loss from cultivated lands.
- Soils form naturally by weathering; if protected from erosion, sound management can maintain or enhance their nutrient levels and textural characteristics.
Answer:
Smaller the size of the DNA fragment, farther it moves during electrophoresis. The sketch of the position of the fragments has been drawn in the figure below.
Explanation:
As we know DNA is a negatively charged molecule. So during electrophoresis the fragments move towards the positive electrode because opposite charges attract each other.
Different fragment move different distances according to their size during the electrophoresis. Smallest segment travels the largest distance in the gel medium while the largest one travels least distance.
In the question there are four DNA fragments with base pairs 4000, 2500, 2000 and 400 so the smallest segment with 400bp will be farthest from the starting point and the largest fragment with 4000bp will travel least distance in the gel medium. Their respective positions are shown in the figure below. The starting point is near the negative electrode.
Answer:
Angiosperms evolved during the late Cretaceous Period, about 125-100 million years ago.
hope it helps.
Yes\.............................................