Which of the following animals display radial symmetry?

Animals in the phylum Echinodermata (such as sea stars, sand dollars, and sea urchins) display radial symmetry as adults, but their larval stages exhibit bilateral symmetry. This is termed secondary radial symmetry.

Which of the following is considered a likely explanation for the events of the Cambrian explosion?

Which of the following is considered a likely explanation for the events of the Cambrian explosion? Complex predator-prey relationships and increased atmospheric oxygen levels promoted animal diversification.

Which of the following periods is the earliest during which animals may have appeared?

The most rapid diversification and evolution of animal species in all of history occurred during the Cambrian period of the Paleozoic Era, a phenomenon known as the Cambrian explosion. Until recently, scientists believed that there were only very few tiny and simplistic animal species in existence before this period.

Which of the following correctly lists organisms from least complex in overall development to most complex?

The biological levels of organization of living things arranged from the simplest to most complex are: organelle, cells, tissues, organs, organ systems, organisms, populations, communities, ecosystem, and biosphere.

Which of the following animals displays bilateral symmetry?

Examples of animals that possess bilateral symmetry are: flatworms, common worms (ribbon worms), clams, snails, octopuses, crustaceans, insects, spiders, brachiopods, sea stars, sea urchins, and vertebrates. The symmetry of an animal generally fits its lifestyle.

Which animal phyla has bilateral symmetry?

The vast majority of animals display bilateral symmetry; also known as plane symmetry, this is a trait that applies to 99% of all animals, in the majority of phyla: Chordata, Annelida, Arthropoda, Platyzoa, Nematoda, and most Mollusca.

Which animal phyla appear in the Cambrian explosion?

Echinoderms It is believed that most of the animal phyla in existence today had their origins during this time, often referred to as the Cambrian explosion. Echinoderms, mollusks, worms, arthropods, and chordates arose during this period.

What animals appeared during the Cambrian explosion?

This period lasted about 53 million years and marked a dramatic burst of evolutionary changes in life on Earth, known as the Cambrian Explosion. Among the animals that evolved during this period were the chordates — animals with a dorsal nerve cord; hard-bodied brachiopods, which resembled clams; and arthropods — …

What does the Cambrian explosion tell us about evolution?

All animal evolution for the last half billion years has come from tinkering with these Cambrian body plans. The Cambrian Explosion: For most of the nearly 4 billion years that life has existed on Earth, evolution produced little beyond bacteria, plankton, and multi-celled algae.

What is the evolutionary history of the animal?

Genetic data suggest that multicellular animals evolved around 1000 million years ago; this is supported by fossil embryos from rocks in China that date back 600 million years.

What came first in evolution?

These clusters of specialized, cooperating cells eventually became the first animals, which DNA evidence suggests evolved around 800 million years ago. Sponges were among the earliest animals.

When did the animal kingdom first appear?

This article’s tone or style may not reflect the encyclopedic tone used on Wikipedia.

Location Walt Disney World Resort, Bay Lake, Florida, United States
Operated by Walt Disney World
Opened April 22, 1998
Operating season Year-round
Website Official website

What is the correct order from the lowest to the highest organizational level?

The levels, from smallest to largest, are: molecule, cell, tissue, organ, organ system, organism, population, community, ecosystem, biosphere.

Which of the following is correctly ordered from simplest to most complex?

Summarizing: The major levels of organization in the body, from the simplest to the most complex are: atoms, molecules, organelles, cells, tissues, organs, organ systems, and the human organism.

Which of these molluscs commonly have a hinged shell?

Bivalves are mollusks that have two shells hinged together, held by strong muscles. Clams, oysters, scallops, and mussels are bivalves. This type of mollusk does not have a radula. They are mostly filter-feeders.

Are annelids radial or bilateral?

Morphology. Annelids display bilateral symmetry and are worm-like in overall morphology.

Which of the following animal phyla exhibit radial body symmetry?

Cnidaria Animals in the phyla Cnidaria and Echinodermata generally show radial symmetry, although many sea anemones and some corals within the Cnidaria have bilateral symmetry defined by a single structure, the siphonoglyph.

Is snail bilaterally symmetrical?

The snail has an unsegmented body with bilateral symmetry, and a ventral muscular foot that provides locomotion (Castro and Huber, 2003).

What animals have asymmetry?

Some of the animals that exhibit external asymmetry include:

Why are animals bilaterally symmetrical?

Having bilaterally symmetrical bodies (the same on both sides along an axis) permit them to propel forward in a straight line. In evolutionary history, animals that moved quickly and efficiently from point A to point B would have been more successful and selected for than those who were ineffective at locomoting.

Which of following phyla of animals does not exhibit segmentation?

On the other hand, some animals, such as planarians (phylum Platyhelminthes) or jellyfish (phylum Cnidaria) are not segmented at all. Aside from sponges, all animal phyla have a digestive tract, or gut. Cnidaria and flatworms have a gastrovascular cavity, a digestive tract with a single opening.

What animals belong to phylum porifera?

Sponges (Phylum Porifera) are a group of simple aquatic invertebrates that include three groups – Glass sponges, Demosponges and Calcareous sponges.

How many phyla appear in the Cambrian explosion?

The event was characterized by the appearance of many of the major phyla (between 20 and 35) that make up modern animal life.

Which animal group was a major part of the explosion?

The Cambrian period, part of the Paleozoic era, produced the most intense burst of evolution ever known. The Cambrian Explosion saw an incredible diversity of life emerge, including many major animal groups alive today. Among them were the chordates, to which vertebrates (animals with backbones) such as humans belong.

What caused Cambrian explosion?

Oxygen fluctuations stalled life on Earth Given the importance of oxygen for animals, researchers suspected that a sudden increase in the gas to near-modern levels in the ocean could have spurred the Cambrian explosion.

During what era did the first vertebrates evolve?

First vertebrates Vertebrates originated about 525 million years ago during the Cambrian explosion, which saw rise in organism diversity. The earliest known vertebrate is believed to be Myllokunmingia.

What does Cambrian mean in English?

1 : welsh. 2 : of, relating to, or being the earliest geologic period of the Paleozoic era or the corresponding system of rocks marked by fossils of nearly every major invertebrate animal group — see Geologic Time Table.

What is the Cambrian explosion and how does it relate to both geological and biological evolution?

The Cambrian explosion refers to a period when dramatic biological evolution produced a dramatic increase in biological diversification between 530 and 570 million years ago, with the eventual appearance of almost all living animals today.

What development in animals created fossils that mark the Cambrian explosion?

What development in animals created fossils that mark the Cambrian explosion? Hard, mineralized skeletons. What is preserved in the Burgess Shale?

What important event in animal evolution occurred at the beginning of the Cambrian period?

The Cambrian explosion or Cambrian radiation was an event approximately 541 million years ago in the Cambrian period when practically all major animal phyla started appearing in the fossil record. It lasted for about 13 – 25 million years and resulted in the divergence of most modern metazoan phyla.