Answer:
The correct answer is: Immunosenescence.
Explanation:
- Immunosenescence can be defined as a biological age-related phenomenon due to which the cells of the immune system are unable to function efficiently with increase in age.
- As a result of this the aged individuals becomes susceptible to various infections and diseases.
- This happens because of the following reasons:
- The immune cells are formed from the progenitor cells called the Hematopoetic Stem Cells (HSCs) which are abundantly found in the bone marrow. These cells have the capacity of self-renewal and also differentiation into various types of immune cells. Due to aging, these cells accumulate large number of Reactive Oxygen Species (ROS) that that causes oxidative damage to the DNA. Also, with age the telomere (the repititive DNA sequence located at the chromosome terminal that protects the end of the chromosome from undergoing recombination or fusion with other chromosomes) length shortens resulting in the generation of damage in DNA. All these reduces the self renewal and differentiation capacity of these cells.
- Other cells of the immune system like, the white blood cells, anti-body producing B-cells, cytotoxicity inducing T-cells, natural killer cells also accumulate similar DNA degrading components. This reduces their life time and also the efficiency of their activity.
<span>Histamine might be released for the blood vessels. This will cause them to constrict and stop the inflammation. When an allergen is taken in by the body, this causes the system to release the histamine as a way of helping those blood vessels dilate and lower a person's blood pressure.</span>
Answer:
In plants, light dependent reactions take place in the thylakoid membranes of the chloroplasts.
Answer:
Decrease
Explanation:
The carbon footprint is <u>the amount of carbon (in terms of greenhouse gases) being emitted by human activities</u>. In a situation where <u>social distancing is encouraged, human activity would reduce significantly</u>. Very few people will be outside and the causative agents of pollution (anthropogenic) will be significantly reduced. Further, nature would be able to minimize the impacts of pollution when human activities are less than the threshold capacity.
Let's take an example of coronavirus spread globally this year. The social distancing of 2 meters has significantly reduced the number of people going outside. Ultimately, there are fewer automobiles on the roads and a few industries are running. The result is that the air quality index has been significantly improved. For example, in India, people from 300 km away, can see the Himalayan mountain range very clearly (see image attached). This has not happened in decades after modern industrialization.
