Answer to Question 1
Descriptive studies are designed primarily to document what is going on or what exists. Public opinion polls that seek to describe the proportion of people who hold various opinions are primarily descriptive in nature. For instance, if you want to know what percentage of the population would vote for a Democrat or a Republican in the next presidential election, you are simply interested in describing something.
Relational studies look at the relationships between two or more variables. A public opinion poll that compares the proportion of males and females who say they would vote for a Democratic or a Republican candidate in the next presidential election is essentially studying the relationship between gender and voting preference.
Causal studies are designed to determine whether one or more variables (for example, a program or treatment variable) causes or affects one or more outcome variables. If you performed a public opinion poll to try to determine whether a recent political advertising campaign changed voter preferences, you would essentially be studying whether the campaign (cause) changed the proportion of voters who would vote Democratic or Republican (effect).
Answer to Question 2
a
Examples of Minor Physical Abnormalities Associated with Schizophrenia
Infant monkey is shown with cloth mother from Harlow’s studies.
Examples of specimen collection containers for stool, urine, and swabs for wounds or secretions.
buffers commonly employed for biochemical studies
Farmers’ markets provide fresh, local produce to consumers
Two examples of a single crossover between two nonsister chromatids