What is the difference between Hydrozoa and scyphozoa?
Hydrozoans have a sexual medusa stage and a nonsexual polyp stage, whereas scyphozoans have a shortened asexual polyp stage. Hydrozoans have velum at the medusa that aids in propulsion, but scyphozoan polyps lack this velum.
What are some differences between scyphozoans and Cubozoans?
Key Points. Cubozoans differ from Scyphozoans in their arrangement of tentacles; they are also known for their box-shaped medusa. Out of all cnidarians, cubozoans are the most venomous.
What are the characteristics of Hydrozoa?
Main attributes:
- Internal space for digestion is the gastrovascular cavity.
- Gastrovascular cavity has one opening, the mouth.
- Exoskeleton of chitin.
- Are almoust entirely marine and predators.
- Sexual reproduction produces the planula larvae.
- Two body forms, a polyp and medusea.
- Presence of stinging cells called Cnidocytes.
What are the characteristics of scyphozoa?
Scyphozoans exhibit the main characteristics of cnidarians. They have radial symmetry and are diploblastic, meaning that their body wall consists of the outer epidermis (ectoderm) and the inner gastrodermis (endoderm), which are separated by mesoglea. They have nematocysts, which are characteristic of the phylum.
What makes a Hydrozoa a Hydrozoa?
The Hydrozoa is a subgroup of cnidarians containging approximately 3700 species. It is a diverse group with a variety of life cycles, growth forms, and specialized structures. Like many cnidarians, hydrozoans have both polyp and medusa stages in their life cycle.
How medusae and polyps are different from one another?
Polyps have a tubular shape and are fixed at their base. Their mouth is present at the other end of the tube, and is surrounded with tentacles forming the “head”. Mouth and tentacles face the water. In contrast, medusa have the shape of a contracting muscular bell enabling it to swim.
What is autonomy?
English Language Learners Definition of autonomy : the state of existing or acting separately from others : the power or right of a country, group, etc., to govern itself : the quality or state of being self-governing especially : the right of self-government
Is autonomy an ideal status designation?
Autonomy as an ideal, on the other hand, may well be enjoyed by very few if any individuals, for it functions as a goal to be attained. The reason to construe basic autonomy broadly enough to include most adults is that autonomy connects with other status designators which apply (or, it is claimed, should apply) in this sweeping manner.
What are normatively substantive conditions of autonomy?
On the basis of such a judgment, they argue that normatively substantive conditions should be added to the requirements of autonomy, conditions such as the ability to recognize and follow certain moral or political norms (See Benson 1987, Wolf 1980; for criticism, see Berofsky 1995, ch. 7).
What is autonomy in paternalism?
Autonomy is the ability to so decide, so for the autonomous subject of such interventions paternalism involves a lack of respect for autonomy. See also Paternalism. But as our discussion of the nature of autonomy indicated, it is often unclear exactly what that characteristic involves.
