A scientist performs an experiment to see how plants respond to acid rain. He places the water plants in water of varying pH measurements. The pH levels are 2.5, 6.0, 7.0, and 9.0. Each day, he measures the health of the plants by counting the number of leaves on the plant. The plants used in this experiment typically grow in water at a neutral pH. Why was only one variable tested in this experiment?

The scientist tested one variable to determine what caused the number of leaves to change.
It just happened that way; you can test as many variables as you want.
The scientist ran out of materials so he tested only one variable.
The scientist tested two variables.

i think it's c

small, big, or no change could occur in the phenotype. it could cause something as simple as a cats ears to curl backwards or something as frighting as death. it could also occur in the protien-coding area and have an effect on that but no effect on the amino acids. what has to occur is a changing in the hox gene or the control gene.

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands

answer:

the water molecules are transferred from the roots to the stem or top parts of the tall tree because of important properties of water which are adhesion, cohesion and capillary action. cohesion is the property of water molecules keeps water molecules in a combined state by sharing of bonds between them at the atomic level. adhesion allows the interaction of water molecules with other substances or substrate. adhesion will cause the attachment of water molecules to the wall of the vessel (xylem) of the plant. capillary action occurs when the adhesive force to the vessel wall is stronger than the cohesive force between water molecules. capillary action mimics the transfer of water from a tube or pipe. in this way water utilizes its property to transfer water from down to top level of the plant.