When a seed germinates, its root grows downward in response to gravity. this is called a. thigmotropism b. negative tropism c. gravitropism d. phototropism

advantage of using stem cells in medical research:

1.       it provides medical benefits in the fields of therapeutic cloning and regenerative medicine.

2. it provides great potential for discovering treatments and cures to a variety of diseases including parkinson disease, spinal cord injuries, diabetes, alzheimer’s disease and many more.

3. limbs and organ could be grown in lab from stem cells and then used in transplant or treat illness.

the darker peppered moth species were favored due to the fact that the industrial revolution had made all the nearby trees a darker color instead of white.

"a.) well–developed vascular system."

for example, no new evidence will demonstrate that the earth does not orbit around the sun (heliocentric theory), or that living things are not made of cells (cell theory), that matter is not composed of atoms, or that the surface of the earth is not divided into solid plates that have moved over geological timescales .