(lo4.16) a polygenic disease would be a bad target for gene therapy because

a. polygenic diseases cause symptoms in too many organs to be treated effectively by changing one gene.

b. many genes would have to be successfully changed to treat the disease.

c. in polygenic diseases the gene mutates each time the affected cells divide by mitosis.

d. the parents as well as the children would have to be treated with gene therapy to treat the disease.

B. many genes would have to be successfully changed to treat the disease.

Explanation:

Monogenic diseases are caused due to mutation in one gene and they usually follow Mendelian inheritance. Defective gene can be replaced with the functional variant to restore the normal phenotype.

In contrast, polygenic diseases are controlled by multiple genes. Knowledge of all the genes involved is important as mutation even at one loci can lead to diseased phenotype. Hence coming up with a successful gene therapy is difficult for polygenic diseases. Some polygenic diseases are type 2 diabetes, cerebral stroke and psychiatric disorders.

the unequal cytoplasmic division that  results  in  one egg  and three polar bodies ensures that a fertilized  egg has  ample nutrients  forits journey  to  the uterus.