There Are Cases,particularly in Fruit Flies,in Which a Normal Body

question 46

Multiple Choice

There are cases,particularly in fruit flies,in which a normal body part grows in the wrong spot.For instance,legs on the head growing instead of antennae,or a second set of wings behind the normal pair.What can explain this?

• A)These are due to the reappearance of stem cells,which are totipotent.
• B)These are due to misregulation of hormones from environmental contamination with pesticides.
• C)These occur as a result of mutations in homeotic genes,which normally act to direct development along the anterior-posterior axis.
• D)These naturally occur sometimes in animals that have metamorphic development,due to different organization of homeotic gene expression in larvae versus adults.

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Definitions:

Cardiopulmonary Resuscitation

An emergency procedure combining chest compressions with artificial ventilation in an effort to manually preserve brain function until further measures are taken to restore spontaneous blood circulation and breathing in a person in cardiac arrest.

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A position where the individual is lying flat, facing downwards.

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The maintenance and upkeep practices required for a cast that is used to support and protect a broken bone as it heals.

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A change in color of a body part, typically indicative of injury or disease.