Answer:
d. a second exposure to an allergen
Explanation:
An autoimmune disease is a condition that occurs when the immune system attacks and destroys healthy body tissues by mistake.
Normally, white blood cells (leukocytes), produced in the bone marrow and found in the blood, help to protect the body against invasive and harmful substances known as antigens. Examples are viruses, bacteria, toxins, cancer cells, etc. Leukocytes are a fundamental part of the immune system, whose main function is to produce antibodies that keep the human body protected from the action of these antigens by destroying them.
In the case of autoimmune diseases, the immune system cannot distinguish antigens from healthy body tissues and ends up attacking and destroying normal body cells.
The causes of autoimmune diseases are not yet known, although there are many mechanisms that trigger these diseases. However, we can confirm that these diseases are not caused by a second exposure to an allergen, which is a substance that can induce a hypersensitivity reaction in some people.
<h2>Postzygotic isolation </h2>
Explanation:
In the given information of edible frog both male and female hybrids exist, but when they mate among themselves, they cannot successfully produce offspring which defines that postzygotic isolation exists between the two frog species
- Postzygotic isolation prevents the formation of fertile offspring
- Before the postzygotic isolation can happen, there must be an offspring born from a male and female of two different species
- This means there were no prezygotic isolations, such as the fitting together of the sex organs or incompatibility of the gametes or differences in mating rituals or locations, that kept the species in reproductive isolation
- The offspring of two different species known as a hybrid is not always viable
- Sometimes, they will self-abort before being born and other times, they will be sickly or weak as they develop
True. Halophytes can be found anywhere with a concentration of five times greater than the salt concentration of the ocean.
Answer:
I think buying a car is not a waste of money because a car can get you to places that you need to go whether it near or far .
Explanation:
<h3>Question:-</h3>
When people run long distances, their muscles require increased amounts of oxygen. Which system is responsible for carrying this oxygen to the muscles?
<h3>Answer:-</h3>
Respiratory System.
Did you Know?
Haemoglobin is the pigment of our blood to give red color.
Hope it helps ☃️
