It depends on the case, but usually two variables should be in a controlled experiment.
Photosynthesis releases oxygen as a product.
<span>The organisms in an ecosystem fills the energy role of producer, consumer, or decomposer.</span>
Answer:
Uncontrolled cell division can lead to the formation of masses of cells that can remain in a place called <u>primary </u>tumors or ones that can move called <u>metastatic </u>tumors.
Explanation:
The term primary tumor refers to the original tumor, a place where the tumor first appeared.
Metastatic tumors are tumors that appear in other organs and originate from the primary tumor. Tumor cells can break away from the primary tumor and travel to other locations in the body through the blood or lymph system and form new tumors. This is how metastatic tumors appear.
For example, a brain tumor is a primary tumor if it first appeared in the brain. A metastatic brain tumor is a tumor that appeared in another organ and then spread to the brain.
Danish scientist Hans Christian Gram devised a method to differentiate two types of bacteria based on the structural differences in their cell walls. In his test, bacteria that retain the crystal violet dye do so because of a thick layer of peptidoglycan and are called Gram-positive bacteria. In contrast, Gram-negative bacteria do not retain the violet dye and are colored red or pink. Compared with Gram-positive bacteria, Gram-negative bacteria are more resistant against antibodies because of their impenetrable cell wall. These bacteria have a wide variety of applications ranging from medical treatment to industrial use and Swiss cheese production.
