Why is it sometimes difficult for ecologists to design controlled experiments?

I don't know if this is classified as Biology, but: What does PSI mean, when it is used for water pressure? Is it a) Pressure per Square Inch? Or, b) Pounds per Square Inch?

Discuss the role that these three figures played in the development and spread of rastafarianism: (a) marcus garvey; (b) haile selassie; (c) bob marley

The names of muscles often indicate the action of the muscle. what does the term levator mean?

True or false: the ability for an animal to use nitrogen in the air depends on the decomposition of animals by nitrogen fixing bacteria

In which part of the body is glycogen stored? liver blood pancreas exoskeleton

Which finding would the nurse most expect to find in a neonate born at 28 weeks' gestation who is diagnosed with intraventricular hemorrhage (ivh) ?

If the germs in a vaccine we're not dead or deactivated then the vaccine would

Water is formed when two hydrogen atoms bond to an oxygen atom. When a substance is made of two or more atoms like this, we call it A) a mixture. B) a complex. C) a compound. D) an element.

Which genotype is homozygous? a. XxTt b. XXTt c. xxTT d. Xxtt

In what organelle does the process of respiration occur