Report Abuse. In plants that undergo alternation of generations, a gametophyte is the structure, or phase of life, that contains only half of the total complement of chromosomes: The sporophyte produces spores, in a process called meiosis.
The life expectancy of cystic fibrosis patients has been increasing over the past 40 years. In the 1980s life expectancy of people with cystic fibrosis was 14 years. 10 years back, the life expectancy of a person with cystic fibrosis was around 18 years. Today it is 35 years. The median life expectancy of a newborn with cystic fibrosis has increased from 4 years to 32 years. It has been estimated that there has been more than 10 year increase in the average life expectancy of affected people in North America. Over 90% of the affected infants now survive beyond one year.
Overview of Cystic Fibrosis. Cystic fibrosis (CF) is the most common fatal, inherited disease in the United States (see Incidence). CF causes the body to produce abnormally thick and sticky mucus in several different parts of the body, most prominently in the lungs and other parts of the respiratory system.It also affects the pancreas, leading to serious digestive problems. Cystic fibrosis alters the mucus secretions of the body's epithelial cells.ust as the chromosomes come in pairs, so do the genes: one copy of the gene on one chromosome is from the mother, the other copy on the other chromosome from the father. The defective gene that is responsible for causing cystic fibrosis is on chromosome 7.