A Condition Caused by the Presence of an Extra Chromosome

question 272

Multiple Choice

A condition caused by the presence of an extra chromosome on the 21ˢᵗ pair and characterized by intellectual developmental disorder and various physical anomalies is ______.

• A) Down syndrome
• B) Klinefelter's syndrome
• C) fragile X syndrome
• D) Turner's syndrome

---

Definitions:

Parasympathetic

The part of the autonomic nervous system that is responsible for conserving energy and promoting a "rest and digest" response.

Neurotransmitters

Chemical messengers that transmit signals across a chemical synapse, from one neuron (nerve cell) to another target neuron, muscle cell, or gland cell.

Synaptic Vesicle

A small, spherical packet located within presynaptic terminals of neurons that stores neurotransmitters, which are released into the synaptic cleft during neurotransmission.

Synaptic Cleft

The narrow gap between the presynaptic neuron and postsynaptic cell where neurotransmitters are released to facilitate neuronal communication.