Question

Match each animal with a description of its nervous system: Sea anemone grasshopper human a. paired ventral nerve cords b. nerve net c. brain, spinal cord, peripheral nerves

Short answer

Sea anemone: b; Grasshopper: a; Human: c.

Step-by-step solution

Identify the Animal Descriptions

The descriptions provided correspond to different types of nervous systems. Let's review them: a. Paired ventral nerve cords are typical of many arthropods, such as insects. b. A nerve net is a simple nervous system found in some invertebrates. c. A brain, spinal cord, and peripheral nerves describe the nervous system of vertebrates, such as humans.

Match Sea Anemone with Description

The sea anemone, being a cnidarian, has a simple nervous system. It is best described by a nerve net, which allows the animal to respond to stimuli in a diffuse manner. - Therefore, sea anemone matches with b. nerve net.

Match Grasshopper with Description

Grasshoppers are insects, falling under the category of arthropods. They have a more centralized and organized nervous system with paired ventral nerve cords. - Therefore, grasshopper matches with a. paired ventral nerve cords.

Match Human with Description

Humans, as vertebrates, have a complex nervous system. It is characterized by an intricate arrangement of a brain, spinal cord, and peripheral nerves. - Therefore, human matches with c. brain, spinal cord, peripheral nerves.

Key concepts

Invertebrate Nervous System

Invertebrates are animals that do not possess a vertebral column, or a backbone. They make up a vast majority of animal species, and their nervous systems can vary widely in complexity. Many invertebrates, such as arthropods and mollusks, have a somewhat centralized nervous system, but it is generally more primitive compared to vertebrates.

• In arthropods, such as insects like grasshoppers, the nervous system is characterized by paired ventral nerve cords running along the belly side and connecting to ganglia, which are clusters of nerve cell bodies serving as processing points.
• In others, such as simple flatworms, the nervous system may consist of just a few nerve cords and a less organized neural network.
• Certain invertebrates rely on more network-like structures, like the nerve net seen in cnidarians.

The diversity in invertebrate nervous systems reflects a variety of adaptations to their environments and lifestyles. Despite their simplicity relative to vertebrates, these systems effectively fulfill the basic functions required for survival.

Vertebrate Nervous System

Vertebrates, by definition, have a spinal column, which houses the spinal cord. This structure is part of a more complex nervous system. At its core, the vertebrate nervous system is divided into two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS).

• The CNS consists of the brain and spinal cord. These structures are responsible for processing sensory information, making decisions, and sending signals to the body.
• The PNS includes all the nerves that branch out from the brain and spinal cord, reaching various parts of the body to transmit signals from the CNS to muscles and organs.

Vertebrates, such as humans, have one of the most advanced nervous systems, allowing for complex thought, movement, and interaction with the environment. The complexity of their nervous systems aids in survival, from basic functions to highly sophisticated actions.

Cnidarian Nerve Net

Cnidarians, including animals like sea anemones and jellyfish, possess one of the most basic forms of a nervous system, known as a nerve net. This simple network lacks a central brain or spinal cord but performs essential functions for the organism.

• The nerve net in cnidarians is spread across the body, allowing these animals to respond to stimuli from any direction. It enables basic movements, such as contracting when touched or capturing prey with their tentacles.
• This decentralized form of a nervous system is ideal for organisms with radial symmetry, where symmetry and functionality are spread around a central point rather than one direction.

Despite its simplicity, the nerve net allows cnidarians to carry out essential life processes such as movement, feeding, and responding to their environment. The nerve net serves as a fundamental model of how nervous systems may have evolved over time, from simple to more complex forms in different species.