Symmetry in Organisms

The video discusses how scientists classify the kingdom Animalia into different phyla based on symmetry. It explains the three types of symmetry: asymmetrical, radial, and bilateral. Examples of organisms with each type of symmetry are provided, such as Hydra for radial symmetry and crabs for bilateral symmetry. The video also highlights the unique case of Echinodermata, which exhibits both radial and bilateral symmetry at different life stages.

What is the term used for organisms that can be divided into two identical halves?

• Symmetrical

• Radial

• Bilateral

• Asymmetrical

Which type of symmetry allows multiple planes to divide an organism into identical halves?

• Radial symmetry

• Bilateral symmetry

• Asymmetry

• No symmetry

Hydra is an example of an organism with which type of symmetry?

• Bilateral symmetry

• Radial symmetry

• Asymmetry

• No symmetry

In bilateral symmetry, how many planes can divide the organism into two identical halves?

• None

• Multiple

• Two

• One

Which phylum does the crab belong to?

• Cnidaria

• Arthropoda

• Porifera

• Echinodermata

Which phylum is known for having asymmetrical organisms?

• Echinodermata

• Porifera

• Cnidaria

• Arthropoda

Which phyla are known for radial symmetry?

• Cnidaria and Ctenophora

• Mollusca and Annelida

• Echinodermata and Arthropoda

• Porifera and Arthropoda

What is unique about the symmetry of Echinodermata?

• Adults are bilaterally symmetrical, larvae are radially symmetrical

• Adults are radially symmetrical, larvae are bilaterally symmetrical

• Both adults and larvae are bilaterally symmetrical

• Both adults and larvae are asymmetrical

Which phylum includes organisms with bilateral symmetry?

• Ctenophora

• Porifera

• Cnidaria

• Arthropoda

Which of the following is NOT a characteristic of bilateral symmetry?

• One plane of symmetry

• Multiple planes of symmetry

• Two identical halves

• Common in advanced organisms