Comprehensive Biology: Reproduction, Cnidaria, Flatworms, and Mollusca

What is asexual reproduction?

A form of reproduction that does not involve the fusion of gametes.

What is the medusoid stage in cnidarians?

The free-swimming, jellyfish-like stage of the life cycle.

What is the significance of the zygote in reproduction?

The zygote is the fertilized egg that develops into a new organism.

What are the main classes of Cnidarians?

1. Anthozoa (sea anemones, corals) 2. Cubozoa (box jellies) 3. Hydrozoa (hydras, Portuguese Man o' war) 4. Scyphozoa (true jellyfish).

What is unique about the Cubozoa class?

They are strong swimmers and some species can be fatal to humans.

What is the primary characteristic of the Hydrozoa class?

They can exist in both polyp and medusa forms.

What distinguishes the Scyphozoa class?

Jellyfish in this class have a more conspicuous and complex medusa stage.

What are Acoelomates?

Animals that lack a coelom, characterized by bilateral symmetry and high levels of specialization.

What are Ecdysozoans?

Animals that molt their exoskeleton, including arthropods and nematodes.

What are the two large groups of Ecdysozoans?

Arthropods and Nematodes.

What is the significance of the Phylum Platyhelminthes?

It includes flatworms, many of which are parasitic.

What are the two groups of flatworms?

1. Free-living (Class Turbellaria) 2. Parasitic (Class Neodermata).

What is Schistosomiasis?

A disease caused by blood flukes that affects 5% of the world's population.

How do people get infected with Schistosomiasis?

By drinking contaminated water where the larvae penetrate the skin.

What are the characteristics of Phylum Rotifera?

They are bilaterally symmetrical, unsegmented pseudocoelomates with a complete digestive tract.

What is the economic significance of Phylum Mollusca?

Mollusks are an important source of human food and have significant economic value.

What are the main body parts of mollusks?

Mantle, foot, and visceral mass.

What is the role of the mantle in mollusks?

It secretes the shell and covers the body.

What is a tapeworm?

A parasitic flatworm that attaches to the intestinal wall of its host.

What is the life cycle of a tapeworm?

It often involves multiple hosts and can be acquired through ingestion of contaminated food.

What is the function of the suckers in parasitic flatworms?

They help the flatworm attach to the host's body.

What is the primary means of locomotion for many mollusks?

The muscular foot.