That question, this incomplete. The full question is:
3. Three redwood trees are kept at different humidity levels inside a greenhouse for 12 weeks. One tree is left outside in normal conditions. The heights of the trees are measured once a week. What are the dependent variables, independent and the controlled variable of this experiment?
Answer:
- Independent variable: different humidity levels
- Dependent variable: the heights of the trees
- controlled variable: the types of trees
Explanation:
An independent variable is one that exerts an influence within the experiment and can be measured, acting on other elements to promote the observation of a result. As the experiment seeks to observe the influence of humidity on the height of the tree, we can say that humidity is the independent variable.
Dependent variable is that which is influenced by the independent variable to generate a result that can be observed, can also be measured. As the experiment wishes to analyze how the height of the trees was affected by the level of humidity, we can say that the height of the trees is the dependent variable.
Controlled variable is that which is present in the experiment in a constant and equal way, cannot be measured. This variable is the type of trees.
The first reason was that his theory of continental drift was just too weak for most geologists to accept. Even though he believed the supercontinent that broke up into different continents moved, he did not have a clear explanation to how the continents moved. The other reason is that some of his explanation clashed with ideas that were widely accepted in the science communities. He used similar fossils from different continents to back up his theory of continental drift. However, at that time, many scientists that had observed similarities in fossils in places like South America and Africa believed there were similar fossils in different continents because of a land bridge that were formed by two continents.
Many science communities believe that land bridges allowed migration of many different species and even people to one place to another by large bodies of water frozen by low temperature known as ice age.
Answer: C. is your answer