Answer:
I and III only
Explanation:
Crop rotation is a farm practice that involves cultivating different species of crops on the same land at different seasons. In other words, the different crops are rotated. Crop rotation is done for various reasons including; improvement of soil fertility, pest and disease control etc.
In this case, a crop rotation of various grains and legumes would be an appropriate solution for the following problems:
- The nutrients in the soil on a farm are being depleted: Legumes are known to be rich in nitrogen and hence add nitrogen to the soil due to the nitrogen-fixing microbes in their roots. Hence, rotating between grains and legumes can help return the depleted nutrients (by grains) to the soil.
- A particular kind of pest is infesting the soil on a farm: Most pests are usually crop-specific, hence, planting only one type of crop can make that soil be infested with a particular kind of pest. However, rotating between crops such as grains and legumes can make a particular pests become scarce or less populated.
The enzyme responsible for that is DNA helicase.
A fixed allele is an allele that is the only variant that exists for that gene in all the population
Oxygen, carbon, and hydrogen
