What nervous system structure is used by sea star?

The sea star has no brain, but a nerve ring in its center, like a relay station that coordinates the movement of its arms. This nervous system relays impulses from light, touch and chemical sensors around its body. Five arms mean a different way of moving through the world.

What organisms have nematocysts?

nematocyst, minute, elongated, or spherical capsule produced exclusively by members of the phylum Cnidaria (e.g., jellyfish, corals, sea anemones).

What organisms have neurons?

Diversity of Nervous Systems All animals have a true nervous system except sea sponges. Cnidarians, such as jellyfish, lack a true brain but have a system of separate but connected neurons called a nerve net. Echinoderms, such as sea stars, have neurons that are bundled into fibers called nerves.

What type of nervous system do chordata have?

In chordates, the central nervous system is based on a hollow nerve tube that runs dorsal to the notochord along the length of the animal. In vertebrates, the anterior end of the nerve tube expands and differentiates into three brain vesicles.

What type of nervous system do you think echinoderms have evolved?

In the echinoderm lineage, the nerve cord evolved into the circumoral nerve ring and radial nerves. These two nervous systems remained separate in hemichordates, but united in chordates.

Which animal brain has the most neurons?

Dogs Have the Most Neurons, Though Not the Largest Brain: Trade-Off between Body Mass and Number of Neurons in the Cerebral Cortex of Large Carnivoran Species.

Which animal brain is closest to a human’s?

The studies were recently published in eLife. The chimpanzee is often thought of as the animal most similar to humans. Our DNA is 98% similar to that of chimpanzees, so you’d think that people resemble this species of monkeys.

Which animal has most neurons?

Lo and behold, the African elephant brain had more neurons than the human brain. And not just a few more: a full three times the number of neurons, 257 billion to our 86 billion neurons.

Which animal has the most neurons?

The largest number of cortical neurons in non-primate mammals is found in the false killer whale with 10 500 million and the African elephant with 11 000 million, which is less than the number found in humans, despite the much larger brains of the former two. Herculano-Houzel et al.

Which animals have the most neurons?

The largest number of cortical neurons in non-primate mammals is found in the false killer whale with 10 500 million and the African elephant with 11 000 million, which is less than the number found in humans, despite the much larger brains of the former two. Herculano-Houzel et al.

Which class of flatworms are not parasitic?

The majority of members of the phylum Platyhelminthes (the flatworms—a phylum that includes the notorious tapeworms and flukes) are parasitic; planarians are labeled the only free-living (non-parasitic) flatworms in the bunch. Planarians are easily overlooked, but amazing, critters.

Which group of cnidarians have a symbiosis with algae?

The symbiotic association between the invertebrate phylum Cnidaria (Coelenterate) and the unicellular dinoflagellate algae, called zooxanthellae, is very common. The most well-known relationship is between zooxanthellae and hermatypic, or reef-forming, corals.

Which organism does not have nervous system?

The only multicellular animals that have no nervous system at all are sponges and microscopic bloblike organisms called placozoans and mesozoans.

Which part of the nervous system is located on the dorsal side in earthworm?

Question Describe nervous system of earthworm
Chapter Name Structural Organisation In Animals
Subject Biology (more Questions)
Class 11th
Type of Answer Video

Which type of flatworm is a planarian?

planarian, (class Turbellaria), any of a group of widely distributed, mostly free-living flatworms of the class Turbellaria (phylum Platyhelminthes). Planaria is the name of one genus, but the name planarian is used to designate any member of the family Planariidae and related families.

Which type of nervous system is found in flatworms?

Summary. The flatworms occupy a position at the base of the metazoan phylogenetic tree; they have a bilateral symmetric nervous system and an archaic brain.

Why are neurons only found in animals?

Why are neurons only found in animals? Based on what this article says about neuron function, why wouldn’t they be helpful for plants or microorganisms? Neurons enable thought, perception, and movement. Plants do not move, so they do not need this type of tissue.

Does sea anemone sting?

We house various types of anemones in our home aquariums. The most common of which is the bubble tip anemone Entacmaea quadricolor. Other anemones like the long tentacle and carpet anemones are also kept, but the species of the anemone is useless for this conversation. Anemones possess stinging cells called nematocysts. As soon as a fish, invertebrate, or careless hand grazes the surface of an anemone, thousands of these stinging cells pierce the victim’s outer coverings. For most fish, this is life threatening, but for humans it usually goes unnoticed…or at the very least it just appears that the anemone is sticking to you.

Do snails eat sea anemone?

Several types of snails and sea slugs make meals out of anemones and are able to eat both the body and the tentacles by advancing on the anemone several times despite being stung and then taking bites out of their prey.

How do anemone live?

The largest and most diverse varieties live in shallow tropical waters. Though some are free swimming, most adult anemones stay in one place. They anchor themselves to surfaces or sand with a sticky foot called a pedal disc.

Is dory a boy or a girl?

Dory is the third female protagonist in a Pixar film, the first two being Merida and Joy. She is also Pixar’s third titular character, the first two being Nemo and WALL-E, and the second titular character to be a protagonist overall, the first one being WALL-E.

Is nemo’s dad dead?

They suggest that Nemo was actually dead from the beginning of the film, suggesting that Marlin’s entire family, including Nemo’s mom, Nemo, and all of their other children, were killed by the fish — Meaning there were no survivors.