Why is rare to find fossils of animals from before the Cambrian period?

How do the structure of a prokaryotic chromosome differ from that of a eukaryotic chromosome

There are many ethical issues associated with cloning. Which of the following is NOT a concern? A. that the creation of a human clone is in itself an unethical use of science B. that the rights of the human clone will be respected C.

In the following food chain, which organism is the primary consumer? Grass ⇒ mouse ⇒ snake ⇒ hawk

A patient is brought to the emergency department. he is restless, has dilated pupils, is sweating, has a runny nose and tearing eyes, and complains of muscle and joint pains.

How are sponges alive and living?

The atmosphere of Earth contains primarily which gas? A.) Carbon dioxide B.) Methane C.) Oxygen D.) Nitrogen

Which organism is the primary consumer in this food chain? Oak tree squirrel owl and eagle

Which of the following is NOT caused by gravitational force? A. Gas and dust come together and form a planet. B. Stars cluster together to form a galaxy C. Planetes orbit a star D. Two atoms come together to form a molecule

What are two ways that a flood can negatively impact an ecosystem? A. increasing groundwater levels and depositing sediment B. spreading pollutants over a large area and depositing sediment C.

Which process describes nitrogen fixation? Question 19 options: animals eat plants containing nitrogen and return it to the soil through urination bacteria take nitrogen from the air and convert it to a form usable by plants organisms die and are