Answer:
I. evolved from ancestors that walked
Explanation:
Whales and pythons have vestigial structures, which are structures (hind legs) which are no longer useful to them since they have evolved. The ancestors of the whale and python did use the hind legs but over generations the whale and snake have adapted to new environments and they no longer need them.
you need to ask a hypothesis
Answer:
This question is asking to identify the following:
Independent variable: Different humidity levels
Dependent variable: Height of the plant
Control group: Tree left outside in normal conditions
Controlled variable: same time of measurements (once in a week), same types of trees
Explanation:
Independent variable is the variable that the experimenter changes or manipulates in an experiment. In this experiment, three redwood trees are kept at different humidity levels. Hence, the independent variable is the DIFFERENT HUMIDITY LEVELS the redwood trees were kept at.
Dependent variable is the variable that is measured in an experiment. It is the variable that responds to the changes made to the independent variable. In this case, the HEIGHTS of the trees measured is the dependent variable.
Controlled variable or constants are those variables that must be kept unchanged throughout the experiment for all groups. In this experiment, the constants are: same time of measurements (once in a week), same types of trees (redwood).
Control group is the the group in an experiment that does not receive experimental treatment. In this case, the group that does not receive treatment/control group is: Tree left outside in normal conditions.
Answer:
The respiration in amoeba occurs by simple diffusion, the oxygen gas dissolved in water or surrounding environment is diffused into the cell through the cell membrane. This oxygen is used for respiratory metabolic purposes. Carbon dioxide gas produced gets removed by simple diffusion into the surrounding environment.
