You need to know if the parents trait are dominant or recessive
Answer:
I'll inform them that the possibility of all their future children/offspring being phenotypically sickle-celled is very high.
Explanation:
Sickle cell is an inherited disease condition in which the red blood cells of the blood loses its shape and hence, dies or gets broken down. It has to do with the blood genotype of an individual. There are three major types of blood genotypes in humans namely: AA, AS, and SS. SS is the recessive genotype that codes for the sickle cell trait.
Hence, a human with the sickle cell trait has a genotype- SS. Therefore, according to this question, a man and a woman, each with sickle-cell trait (SS), were planning to marry, This will mean that both the man and the woman will always produce a gamete with S allele, which will combine to form an SS offspring. In other words, all of the offsprings of this man and woman will be sickle-celled.
Striated muscles contain repeating sarcomeres of overlapping arrays of long, thin actin and thicker myosin filaments. Myosin filaments contains the myosin heads, which are enzymes that can bind to actin, split and make use of the energy from ATP. When muscle contraction starts, myosin heads bind to actin, change their configuration on actin, liberating the products of ATP hydrolysis and causing slide of the actin and myosin filaments. The action of the proteins troponin and tropomyosin on the actin filaments regulates vertebrae striated muscle contraction. The release of calcium ions from the sarcoplasmic reticulum is triggered by the nervous stimulation which causes depolarization of muscle membrane. Calcium ions bind to troponin and thus cause or allow the tropomyosin strands on the actin filament to move so that the part of the actin surface where myosin heads need to bind is uncovered. Contraction then occurs and only stops when the sarcoplasmic reticulum pumps calcium out of the muscle interior.
So basically, what triggers the uncovering of the myosin binding site on actin is the calcium ions binding to troponin and changing configuration.
