Answer:
d. secondary endosymbiosis.
Explanation:
- When a living cell acquires another organism that eventually becomes a part of this cell, this process is known as primary endosymbiosis.
- When an organism that has already undergone primary endosymbiosis engulfs another eukaryotic organism then this process is known as secondary endosymbiosis.
- Secondary endosymbiosis has been known to occur in plastids because of which they are surrounded by two membranes. This bilayer is present because one of the layers is the original outer membrane of the organism and the other membrane is that of the organism that has been engulfed.
Answer: Cystic Fibrosis
Explanation:
Cystic fibrosis (abbreviated CF) is an autosomal recessive genetic disease that mainly affects the lungs, and to a lesser extent the pancreas, liver and intestine, causing an abnormally thick, sticky mucus to build up in these areas. This mucus collects in the airways of the lungs and pancreas. The main cause of morbidity and mortality is pulmonary involvement, which accounts for 95% of deaths, mainly due to repeated infections caused by bronchial obstruction due to the secretion of very thick mucus.
This build up of mucus causes life-threatening lung infections and serious digestive problems. It is one of the most common types of chronic lung disease in children and young adults, and is a life-threatening disorder; patients often die from lung infections due to <em>Pseudomonas</em> or <em>Staphylococcus</em>.
<u>It is a hereditary disease produced by a mutation in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) protein. This protein is involved in the passage of chlorine ion through cell membranes and its deficiency alters the production of sweat, gastric juices and mucus. </u>The disease develops when neither allele is functional. Over 1500 mutations have been described for this disease, most of which are small deletions or point mutations; less than 1% are due to mutations in the promoter or chromosomal rearrangements. However, many people carry the CF gene, but do not have any symptoms. This is because a person with this disease must inherit 2 defective genes, 1 from each parent.
<u>There is no curative treatment, however there are treatments that allow the improvement of symptoms and extend life expectancy. In severe cases, the worsening of the disease may necessitate a lung transplant.</u>
ok yeah we know you know that bro I know it's fun right
The difference between an artery and a vein is that arteries are larger, more muscular and more elastic than veins; they carry blood that is under pressure from having been pumped out of the heart; veins are under much less pressure, so they are not as strong
