One Would Expect That Defects in the Globin Genes Would $\beta$

question 27

Multiple Choice

One would expect that defects in the globin genes would be so serious as to cause death in utero. Which of the following explains how some thalassemias are found in living people?

• A)in \(\beta\)-thalassemia, the use of the \(\gamma\) subunit allows individuals to live a normal lifespan
• B)individuals who completely lack functional \(\alpha\) subunits can live if placed in a hypobaric chamber to induce hypoxia
• C)since humans have 4 copies of the \(\alpha\) chain gene, effects are only seen when at least 3 of the genes are nonfunctional
• D)individuals with nonfunctional \(\alpha\) chain genes can make \(\beta\)₂\(\gamma\)₂ tetramers that function normally
• E)none of the above

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Definitions:

Accounts Receivable

Unpaid customer debts to a company for goods or services that have been supplied.

Bad Debts Expense

An expense reported on the income statement reflecting the cost of estimated uncollectible accounts receivable.

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Sales made on credit minus any sales returns or allowances, reflecting the actual credit sales revenue.

Uncollectible Accounts

Debts owed to a company that are considered to be uncollectable and are therefore written off as a bad debt expense.