Describe at least two advantages and at least two disadvantages of using embryonic stem cells to repair damaged tissue due to injury or disease. Be sure to use a topic sentence and conclude with a summary.

d. planting trees

the trees take in carbon to make oxygen.

what is this saying?

the nitrogen cycle provides nitrogen to the ecosystem from the atmosphere, ground and oceans. nitrogen is an important component of complex molecules such as amino acids and nucleotides, which lead to the creation of proteins and dna, the building blocks of all life. plants absorb nitrogen in the form of ammonium, nitrate ion and, on rare occasions, as amino acids. animals receive nitrogen necessary for biological processes from feeding on living or dead organic matter.

i think it is d. objects resist changes in their state of motion.