Which of these is not one of the primary gases found in Earth's atmosphere?

helium

nitrogen

oxygen

carbon dioxide

What is eutrophication? What can speed it up?

What is the significance of sporopollenin in bryophytes?

Which cell structure belong to fish embryo cell? Select all that apply. Cell membrane, cell wall, chloroplast, mitochondria, and nucleus.

This type of metabolic reaction gains electrons.

The Milky Way is held together by a black hole's gravitational force. Since the stars near this black hole move at a high speed, what can you infer about the black hole? A. Its location B. Its size C. Its depth D. Its speed

Which stage of the cell cycle involves cell growth and DNA replication? A) mitosis B) cytonesis C) interphase D) prophase

Approximately what percentage of a human's DNA is used for coding information for the synthesis of proteins?

Carbohydrates may form larger carbon-based macromolecules by combining with which elements? A.) sodium, potassium, nitrogenB.) nitrogen, sulfur, phosphorusC.) potassium, sodium, sulfurD.) silicon, phosphorus, sodium

What type of chemical reaction is used by liver cells when synthesizing glycogen from glucose?

Select the correct answer. How is a conductor different from an insulator? A. The free movement of electrons within a conductor permits the transfer of charge. B. The free movement of protons within a conductor permits the transfer of charge. C.