A Few Decades Ago, Knudsen and Colleagues Proposed a Theory

question 39

Multiple Choice

A few decades ago, Knudsen and colleagues proposed a theory that, for a normal cell to become a cancer cell, a minimum of two genetic changes had to occur in that cell. Knudsen was studying retinoblastoma, a childhood cancer of the eye.
-One of the human leukemias, called CML (chronic myelogenous leukemia) , is associated with a chromosomal translocation between chromosomes 9 and 22 in somatic cells of bone marrow. Which of the following allows CML to provide further evidence of this multistep nature of cancer?

• A) CML usually occurs in more elderly persons (late age of onset).
• B) The resulting chromosome 22 is abnormally short; it is then known as the Philadelphia chromosome.
• C) The translocation requires breaks in both chromosomes 9 and 22, followed by fusion between the reciprocal pieces.
• D) CML involves a proto-oncogene known as abl.
• E) CML can usually be treated by chemotherapy.

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Definitions:

Retrieval Cue

Stimuli or signals that can trigger the memory of a previous experience, making it easier to recall information.

Encoding Specificity Principle

The theory that memory is improved when information available at encoding is also present at retrieval.

Sensory Store

A very short-term form of memory that allows individuals to retain impressions of sensory information after the original stimuli have ended.

Retrieval Cue

A trigger or stimulus that aids the recall of information from memory.