Answer:
<em>The labels <u>I-VII</u> represent the different stages of primary succession. I-bare rocks, II-pioneers (mosses, lichen, algae, fungi), III-annual herbaceous plants, IV-perennial herbaceous plants and grasses, V-shrubs, VI-shade intolerant trees, VII-shade tolerant trees.</em>
Recessive genetic disorders result from inheriting 2 defective recessive alleles of gene ( one from each parent ). The x - chromosome holds about 10% of all human genes. Sex chromosomes are: males XY, females XX. Y-traits occure in males only. Y-disorders are rare.
Answer: Most recessive disorders are on the Autosomal recessive gene, and thus not x-linked.
C: conducting an experiment
The situation is an example of negative reinforcement.
In the condition of negative reinforcement, a stimulus especially an unpleasant stimulus is removed due to a particular behavior of the person. In this case, the unpleasant behavior is the headache, and taking aspirin is a behavior of Nancy, which cut of the stimuli, that is pain relieving. In negative reinforcement a particular behavior is increased, in order to remove the unpleasant stimulus.
