Rank the following epidemiologic study designs in order from increasing to decreasing validity (1 being highest validity and 4 being lowest validity): a. Cross-sectional studies b. Cohort studies c. Randomized Controlled Trials (RCTs) d. Case-control studies

the sphincter muscles at the end of the digestive tract is the anus.

correct answer: understand the different control methods available

integrated pest management is an strategy that is based on the ecosystem and try to prevent the pest and the damage caused by them by applying combination of technique like habitat manipulation, biological control and use of resistant varieties.

the main aim of the integrated pest management is not to completely eliminate the pest but to strengthen the ecosystem so that conditions are favorable for plants and unfavorable for pests.

not necessarily. higher fitness requires the organism to be reproductive successful. for example, an organism at age 10 with 15 offspring is much more fit than an organism at age 15 with only 5 offspring.