1.observation is made using one or more of the five senses. 2. An independent variable is a variable that's
changed in an experiment.
3. An explanation based on an observation is alan
4. There may be only one variable in an experiment.
5.observation is made using tools or measurement.
6. What's the difference between an observation and inference?

Below, the levels of organization in a multicellular organism are shown from least to most complex. which level of organization can be described as several different types of tissues working together to perform a common task?

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.

Climate like that in the sahara desert have the fastest rates of weathering