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.
Answer:
y is there so much letters?
Answer:
False
Explanation:
Xrays show images of metallic/bone or plastic objects. It shows if there are any breaks or objects not supposed to be there.
Well for one the impact of age of course, is not limited to organisms. overtime your DNA accumulates damage.
<span>The random changes a mutation causes to an organisms genetic code causes either
1. A different protein to be produced or
2. none at all
Mutations can either have a positive, negative or neutral (the vast majority) effect on the organism. (many times whether they are harmful or helpful depends on the environment.)
When a mutation makes an organism better able to survive that organism is more likely to survive and pass the mutated gene onto the next generation.</span>