<span>Recombinant DNA if that is an option</span>
The thing that would mostly make the results of the experiment invalid would be the students themselves. No one is built the same, and the exact same food can have very different effects on different people.
Answer:
preparedness.
Preparedness is the tendency to learn some associations more easily, quickly and permanently than others.
Answer: alternative A.
Explanation: Fixism was a current theory during biology history, and it stated that species were always like they are at the present time, not being able to change during time. Darwin's evolutionary theory, developed at the 19th century, said the opposite: species were able to change and they still do it. One way to prove it was <u>studying fossils and its morfologycal characteristics in order to link them to more recent species</u>, and <u>establish a taxonomical connection between them</u>. The study of fossils is know as paleontology, and it this way it changed the naturalist's views.
The crabs are salt water organisms, so they'll have a higher concentration gradient than the distilled water. In other words, they're hypertonic to the distilled water. This will cause them to take on water and expand; their cells bursting.
