Normally conducted seven weeks into the pregnancy, is used to detect structural abnormalities in the fetus and when used later in the pregnancy can determine whether the baby is a boy or a girl.

Ultrasound

Explanation: Ultrasound through the use of Ultrasonic devices are used in medicine to detect objects and measure distances.

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.