Answer:
The two types of cells that never go through cell division once fully formed are nerve cells and muscle cells.
Explanation:
The nerve cells and the muscle cells not undergo cell division after formation, because they can never re grow or cannot be repaired once they are mature. We should take good care of it once they are matured. They just under division from being baby to teenagers after that they stop undergoing cell division. This is true for both elephants as well as human beings. This thing is also applicable in case of bones.
Answer:
Microtubules, like actin filaments, are dynamic structures: they can grow and shrink quickly by the addition or removal of tubulin proteins. Also similar to actin filaments, microtubules have directionality, meaning that they have two ends that are structurally different from one another. I hope this helps :)
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.
Answer:
Interrupt the long winter nights with a brief period of light.
Explanation:
Long day plants, also called short night plants, flower when the dark period is equal or less than the critical period specific for the species. These plants normally flower in summers when nights are short and days are longer. Winters have a long dark period and do not support flowering in shirt night plants.
A continuous dark period is critical for flowering. A short night plant can flower in winters (having longer dark periods) if the dark period is interrupted by exposing the plant with a flash of light. To make short night plants, such as iris to flower in winters, the plant should be given short period of light after completion of critical dark period.
