The Insect Body Plan Includes Many Groups of Serially Repeated

question 50

Multiple Choice

The insect body plan includes many groups of serially repeated units.For example,there are typically three pairs of legs,one on each of the three segments of the thorax.Which option best describes how these pairs of legs develop and evolve?

• A)The body parts develop in a modular fashion.Therefore,a genetic change could alter the development of one pair of limbs without noticeably changing the rest of the insect's body plan.
• B)A single gene controls the development of all six legs.Thus within a species,all three pairs of legs are identical.
• C)The leg pairs all influence each other during development.Gene products move by diffusion from one segment to the other.Therefore,it is impossible to alter the development and form of one pair of legs without causing similar changes in the other two pairs of legs.
• D)The leg pairs grow under the control of an ancient set of highly conserved genes.Therefore,all insects have more or less identical legs.Other parts of the insect body plan can evolve somewhat more freely.

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Definitions:

Object Permanence

is the cognitive understanding that objects continue to exist even when they cannot be seen, heard, or otherwise sensed, a fundamental concept in developmental psychology.

Sensory-Motor Stage

The earliest stage in Piaget's theory of cognitive development, where infants learn about the world primarily through their senses and motor activities.

Egocentrism

A cognitive trait that describes the inability to differentiate between one's own perspective and another person's perspective, often seen in early childhood development.

Attachment

A lasting emotional connection that ties one individual to another, regardless of distance and time.