Studies of Identical and Fraternal Twins Indicate That About ________

question 561

Multiple Choice

Studies of identical and fraternal twins indicate that about ________ percent of the difference among people's happiness ratings is heritable.

• A) 10
• B) 30
• C) 50
• D) 70

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Definitions:

Viral Infection

An illness caused by viruses, microscopic infectious agents that replicate inside living cells of organisms.

Saliva

A watery fluid secreted into the mouth by glands, providing lubrication for chewing and swallowing, and aiding in digestion.

Lymphoid Tissue

Tissues that form part of the immune system, including the lymph nodes, spleen, and tonsils, which produce and store cells that help fight infection and disease.

Lymphoid Tissue

Specialized connective tissue in the lymphatic system, containing large numbers of lymphocytes, that helps protect the body against infection.