I think the correct answer is the first option. The key features of chordates would be notochord, dorsal tubular nerve cord, pharyngeal pouches, and a tail. These features appears in some period of their lives. They are deutorostomes where the anus would be formed first before the mouth.
Bilirubin is a byproduct of red blood cell destruction and are conjugated in the liver and excreted in bile.
The white blood cells attack the infection
Answer:
Something that can be tested, or rationalized.
Explanation:
You didn't give any statements to choose from, so I'll give you a rule of thumb. When finding a scientific statement, make sure it's something like "The tide is higher at noon than it was at 3 am." and not "Your dog is itchy, so that means a bad storm will arrive."
Heterotrophs depend on autotrophs for food (energy). Autotrophs don't neccessarily depend on heterotrophs. In some cases heterotrophs may spread their seeds, such as a bee spreading pollen, so in that case they would.
