X-shaped chromosomes are linked together at the

Centromere

Explanation:

Centromers are regions of the primary constriction of the chromosome. In this place, the kinetochore is located, a structure formed by proteins that guarantee the connection of sister chromatids (X-shaped chromosomes) in the mitotic spindle. The centromere allows the chromosome to be divided into arms, which may have different sizes depending on the position of the centromere. When we observe an unduplicated chromosome, it is possible to notice the presence of a centromere and two arms. From this we can conclude that the X-shaped chromosomes are linked through the centromere.

parasites can detrimentally affect their host, but also must not allow their host to die before they can complete their life cycle. some parasites have complex life cycles with many different hosts, and have had to find ways of persisting in many different environments during the change from one host to another. ectoparasites live outside the body of the host, and can more easily  disperse, but are  more exposed to predators, parasites, parasitoids. endoparasites live inside the body of the host, and are therefore protected from the outside environment. but they can be  attacked by the host's immune system. they have therefore developed  mechanisms for dispersal such as  complex life cycles.

the answer is a) a shiprock was formed by igneous process