Carbon and nitrogen and an important element of living things. Nitrogen is a major component of DNA and amino acids while carbon can be found in almost all biomolecules. These elements, therefore, need to be renewed and recycled as they are utilized by ecosystems that is ever dynamic.
The answers that best fit the blanks are MATERNAL BLOOD ANALYSIS and ULTRASOUND, respectively. In prenatal diagnosis, there are certain methods that should not be done routinely for the reason that these may injure the fetus, except for routine ultrasound, which checks the status of the fetus, and maternal blood analysis, which assesses the current status of the mother.
<span>There are many indicators for predator presence. Some of them are:
Being able to spot predator marks like scratches or fur.
Being able to feel predator movements.
</span><span>Echo-location </span>For example, moths respond to the echo-location calls from their bat predators; moths drop to the ground once they hear the sound pulse from the bat.
