Answer:
See the answer below
Explanation:
For each heterozygous parent with the genotype BbRr, the possible gametes are: BR, Br, bR, and br. A set of these gametes from one of the parents will be lined up along the top of the Punnet's square while another set from the other parent will be lined up along the side of the square.
The result is shown in the attached image.
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.
Where are the answer choices?
Answer:
1 - Malaria
2- Typhoid fever and Tuberculosis
Explanation:
In case of malaria, the causal microorganism is Plasmodium falciparum, which target red blood cells of host. In humans who have defective sickle cell allele, have abnomral shaped red blood cells. So microorganism does not able to attach to abnormal shaped RBCs thus humans having sickle cell allele are more resistant to death caused by malaria.
In cystic fibrosis, mutation on that gene which encodes a protein known as cystic fibrosis transmembrane conductance regulator (CFTR).
Normally Salmonella typhi (bacteria responsible for typhoid fever) enters into intestinal cells by attaching with CFTR receptor. Carriers of cystic fibrosis mutant gene, have abnormal CFTR thus reduced rate of entry of bacteria into carriers.
Normally Mycobacterium tuberculosis (bacteria responsible for tuberculosis) adds sulfate in its cell walls. In carriers of cystic fibrosis, arylsulfatase B activity is reduced which incorporates sulfate. Thus reduced arylsulfatase activity makes bacteria unable to add sulfate in its cell walls thus decreases their virulence to carriers of cystic fibrosis.
