Phylum Cnidaria Part 1: Introduction and Broad Characteristics

The video tutorial provides an in-depth look at the phylum Nidaria, covering their evolutionary history, unique stinging cells called nidocytes, and the mechanism of nematocysts. It explains the anatomy and physiology of Nidarians, including their diploblastic structure, nerve net, and radial symmetry. The tutorial also explores the polymorphic nature of Nidarians, their diverse habitats, and symbiotic relationships. Finally, it discusses their reproductive strategies, including both sexual and asexual reproduction, and their ability to regenerate, with some species being biologically immortal.

What is the primary characteristic that distinguishes Nidaria from other phyla?

• Presence of a backbone

• Ability to fly

• Unique stinging cells called nidocytes

• Photosynthetic capabilities

How do nematocysts release their venom?

• By electrocution

• By releasing venom-filled harpoons

• By secreting a toxic gas

• By biting

What prevents a nidarian from stinging itself?

• A special type of mucus

• Confirmation from surrounding cells

• A thick layer of skin

• A protective outer shell

What type of symmetry do nidarians exhibit?

• Bilateral symmetry

• Radial symmetry

• Asymmetry

• Spiral symmetry

Which layer in nidarians contains most of the sensory cells?

• Endoderm

• Mesoderm

• Ectoderm

• Mesoglea

What is the primary function of the gastrovascular cavity in nidarians?

• Locomotion

• Photosynthesis

• Gas exchange and digestion

• Sound production

Which form of nidarian is adapted for a sedentary lifestyle?

• Polyp

• Zooplankton

• Hydra

• Medusa

What type of relationship do clownfish have with sea anemones?

• Competitive

• Parasitic

• Mutualistic

• Commensal

How do nidarians typically reproduce asexually?

• By laying eggs

• By fragmentation

• By binary fission

• By budding

What is a unique feature of some biologically immortal nidarians?

• They have bones

• They can fly

• They do not age

• They can photosynthesize