Answer:
Water erosion refers to the removal of the top most or surface layer of soil by the flow of water. The long term effect of water erosion can be because of drastic rain fall and may be because of flood. These two reasons can adversely effect the human life. The water erosion is responsible for the removal of fertile layer of soil, therefore, the region will not be appropriate to grow vegetation. The long term effect may result in stagnation of water, therefore, long time is required so that the region gets dried. The long term accumulation of water over an agricultural field can spoil the crop production.
Prevention that can be taken to reduce long term effect of water erosion:
1. Plantation of long root bearing trees over flood prone regions and around the agricultural field: This will allow the trees to tightly hold up soil and prevent it's erosion.
2. Add rocks over the soil: In an agricultural field or flood prone area, the rocks will act as barrier for the movement of run off water, hence, will prevent water erosion. It will increase the absorption of water by soil.
3. Building of walls: This will also act as a barrier in a flood prone region and will prevent the water being added up to the agricultural land.
4.Remove soil compaction: If the soil compaction of the effected region is removed, the water retention property of the soil can be improved. Machines, animals and humans can be used for this purpose to remove the compaction of upper layer of soil.
Explanation: hope this helps.
Answer:
e. spores
Explanation:
In the given question, the characteristics of a plant are mentioned which are the dominant sporophyte, cell wall and the Chl a or b.
It is mentioned that the plant has a dominant sporophyte therefore it produces the spores during its life cycle. The other features like the endosperm, seeds, flowers are the characteristics on the basis of which the plant can be characterised as they differ in the plants.
Since the production of spores is a characteristic feature of the sporophyte, therefore, it will be least considered by the botanist to discover a new species.
Thus, Option-E is the correct answer.
Answer:
Taking more samples from different parts of an acre.
Explanation:
Validity and accuracy of the data is crucial for any serious research. In this particular case, the most accurate data would be obtained if earthworms would be counted on the whole acre. Of course, this would consume lot of time, people, money etc. That's why methods for estimation are used. Estimation best works with large number of samples. Since one acre equals over 4000 square meters, taking only five samples from such a big area is simply not enough for obtaining valid data.
One of the possible ways to improve estimation is to take more samples per acre while avoiding taking adjacent samples because it could be possible that number of earthworms in one part of an acre is increased (or decreased) for any reason, which would lead us to wrong conclusion.
Number one is structural and 2 is behavior
Three is structural
Four is structural
The last one behavior
The stomata and their guard cells allows this happen.
Stomata is like a hole or gap on a leaf, most of them are present in a bottom side of the leaf, since waxy cuticle is not present over there. And 2 guard cells make up a stomata.
Guard cells are able to control the size of the stomata, depending on the situation. For example, the guard cells close up during day time because a lot of sunlight may cause more water loss.
In conclusion, guard cells and the stomata are the main structures that allow carbon dioxide and oxygen (water too) diffuse in and out of leaves.
