Let 'C' denote the dominant trait of eye-crossing and 'c' denote the recessive trait of not being able to cross the eyes. The genotype of the father is heterozygous dominant for the trait of eye-crossing. This is denoted by 'Cc'. The mother is homozygous recessive for the trait of eye-crossing, denoted by 'cc'. The mating between the two will result in following genotypes: two of 'Cc' and two of 'cc'. Therefore the probability that the child will be able to cross his or her eyes is 0.5 or 50%.
The answer is d) it encloses specific structures
Endoplasmic reticulum is the answer.
