In an investigation designed to determine the effect of the amount of water on plant growth, two groups of equal-sized bean plan
ts of the same species were grown under identical conditions, except for the amount of water they were given. One group was watered with 200 milliliters of water once a day, while the other group was watered with 400 milliliters of water once a day. After several days, the heights of the plants were measured. It was determined that the plants watered with 400 milliliters of water once a day showed more growth. The variable in this investigation is the
In an experimental design, there are two types of variables: independent and dependent variables. The dependent variable is modified by the independent one. In other words, researchers can change the independent variable to see the possible effect in the dependent one. In this example, the study wants to see the effect of the amount of water (independent variable) on plant growth (dependent variable). They evaluate the height of the plants (growth) exposed to different volumes of water. So, the variable of interest in this study is the height of the plants.
After two months of
development, the embryo is called a fetus. The endometrium is formed in part
from the inner lining of the uterus and in part from other membranes. It is
through the placenta that that the embryo/fetus is nourished while in the
umbilical cord and three blood vessels are carried away.
