a control helps to increase the reliability of the results. it allows a scientist to compare it to other group(s) in an experiment. if a scientist notices a significant different btwn the control and the other groups, he can logically conclude that the independent variable has an impact on the dependent variable.
a variable is any factor, trait or condition that can exist in differing amounts or types. there are usually three tpes of variables in experiments: the independent, dependent and contolled. the independent variable variable is the one that is changed by the scientists to figure it's affect on something.
These two organisms may have evolved by coevolution. The last option in the given question is the correct option. The Latin-American humming birds had to evolve as per their surroundings, otherwise they would have become extinct in that region. For that sole purpose they had to have the long and curved bills. The flowers needed the humming birds for their pollination. To attach with the legs of the humming birds in the region, the flowers had to become sharply curved. The humming birds had to come in contact with the flower while sucking the nectar. this helped the plants in their pollination process. so both became mutually beneficial to each other.
Answer:
Phagocytosis is the taking in of large food particles, while pinocytosis takes in liquid particles. Receptor-mediated endocytosis uses special receptor proteins to help carry large particles across the cell membrane.
Explanation:
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Intrusive is crystallized below the surface
<span>extrusive is when lava crystallizes on earths surface</span>
