Which cell structure is mainly responsible for releasing energy from food molecules in some single-celled organisms?

Sickle cell amelia is a condition condition where the red blood cells are deformed which is affected by sickle cell amenia

As the earth formed, the force of gravity increased due to increased mass. what effect did this increased gravity have on the forming planet?

Which statements explains what the fossil records indicates? check all that apply. a) earth is 4.5 billion years old b) many organisms have become extinct c) mammals have always existed on earth d) mass extinctions have occurred several times on earth e) the amount of water on earth has decreased over time?