Question

Enclosed within axons are ____, which are hollow spheres containing ____.

a.
peroxisomes; myelin
b.
vesicles; myelin
c.
peroxisomes; chemical messengers
d.
vesicles; chemical messengers

Answer 1

The correct answer is (b) vesicles; myelin

Step-by-step explanation:

because axons, the long projections of neurons, contain vesicles, which are membrane-bound sacs responsible for transporting and releasing neurotransmitters. Myelin, on the other hand, is a fatty substance that surrounds and insulates axons, facilitating faster nerve impulse transmission. Therefore, vesicles within axons are involved in neurotransmitter release, while myelin is associated with insulation and faster conduction of nerve impulses.

Answer 2

Enclosed within axons are vesicles, which contain chemical messengers, not peroxisomes or myelin. The myelin sheath is composed of tightly wrapped glial cell membranes around the axon.option d is correct answer.

Step-by-step explanation:

Enclosed within axons are vesicles, which are hollow spheres containing chemical messengers. Vesicles in neurons are used to store neurotransmitters that are released at the synapse during neural communication. The other option, peroxisomes, is not what is found within axons for the transmission of nerve impulses. Peroxisomes are specialized compartments within cells that break down fatty acids and detoxify certain chemicals.

The myelin sheath is not enclosed within axons but rather is a layer that wraps around the axon. This sheath is composed of the tightly wrapped plasma membrane of glial cells—Schwann cells in the Peripheral Nervous System (PNS) and oligodendrocytes in the Central Nervous System (CNS)—which allows for faster transmission of electrical signals.

The myelin sheath appears as deep, dark, black color when stained in an electron micrograph due to its lipid-rich composition, which includes not only phospholipids but also important proteins that help to hold the layers of the membrane closely together.