The controlled experiments are performed by the scientists, when they want to study the changes in the sample on changing a single variable. So, the correct answer is option (b).
In case, all variables are kept same, no changes would be observed in the experiment sample. A controlled experiment can be performed on living thing as well as non living. But, controlled experiment cannot be performed on the things which are influenced by a lot of variables, as they cannot create realistic results. So, the option (a), (c), and (d) are incorrect.
d. Sea Cucumber
Sea cucumbers are filter feeder. Sea cucumbers often find places that have strong currents to find food.
Answer:
The answer is B.
Explanation:
Genetic engineering involve the change of genetic material of an organism by removing, changing or inserting individual genes.
Answer:
because the blood in the heart gets what's left of oxygenated blood first. first come first serve concept. the heart cells survive longer because they have oxygenated blood longer and more frequently. if the person is not breathing the oxygen in the blood might run out by transferring to cardiovascular cells before it gets to the brain.
Explanation:
