Biff and His Twin Brother Bernie, Were Part of a Twins

question 96

Multiple Choice

Biff and his twin brother Bernie, were part of a twins study. They were first observed by the researchers when they were 5 years old, and then again later when they were 10 years old. What type of a study were they in?

• A) case
• B) cross-sectional
• C) longitudinal
• D) periodical

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Definitions:

Compound

A substance formed from two or more elements chemically bonded together in a fixed ratio.

3-nitrophthalic Acid

An aromatic dicarboxylic acid compound with a nitro group substituted at the 3-position on the benzene ring.

Pentanedioic Acid

An organic compound also known as glutaric acid, with the formula C5H8O4, characterized by two carboxylic acid groups at each end of a five-carbon chain.

Trans-1,3-cyclohexanedicarboxylic Acid

A type of dicarboxylic acid where the carboxyl groups are located on the first and third carbon atoms of a cyclohexane ring, in a trans configuration.