What are two features all echinoderms have?

In your own words, describe the structure and function of the gastrointestinal tube?

A student has a microscope with a 10x eyepiece and 10x and 40x objectives.

How many dependent variables can be tested during any single experiment?

A Barr body is normally found in the nucleus of which kind of human cell? a. Somatic cells of a female only b. Somatic cells of a male only c. Sperm cells only d. Both male and female somatic cells e. Unfertilized egg cells only

Porque consideras que la cantidad de oxigeno en la atmosfera primitiva influyo en los primeros organismos

Scientists have debated the evolution of three life forms: reptiles, birds and dinosaurs. After many years of reviewing fossil records scientists proposed the evolutionary relationship seen above in the cladogram.

The PNS is divided into several subsystems. What two subsystems form the first major division of the PNS? sensory and motor somatic and autonomic parasympathetic and sympathetic CNS and brain

Consider the model of the food chain. Imagine there is a herbicide poison spill and all the grass is killed. How will this influence the food chain model? A) The grasshoppers will die out. B) All of the consumers will decrease.

A mutation in a dna strand is least likely to affect the cell when the mutation:

What macromolecule has the function of providing structure and catalyzing reactions (as enzymes) ?