Allen Is 3 Years Old

question 109

Multiple Choice

Allen is 3 years old. He ignores people when they are in the room, and if people speak to him he does not make eye contact. He also will not initiate communication, but rather just repeats what someone has said. Finally, Allen plays with a spinning top for hours. He just spins it, watches it, and when it stops spins it again. Allen may be showing signs of _____.

• A) a learning disability
• B) ADHD
• C) autism
• D) bipolar disorder

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Definitions:

Cladograms

A diagram used in cladistics which shows relations among organisms.

Molecular Clocks

Methods used to estimate the time of evolutionary events based on the hypothesis that genetic mutations accumulate at a predictable rate over time.

Fishlike Vertebrates

Aquatic animals featuring a backbone, including both true fish and fish-shaped species with similar living habitats and structures.

Million Years

A time unit used in geology and astronomy to describe extremely long periods, typically used in the context of the age of the earth or the distance of cosmological objects.