Distinguish between radial and bilateral symmetry.?

Question

Describe with the aid of examples and suitable diagrams.

Answer 1

Bilateral basically means that one side is a mirror image of another (e.g. humans). Radial means that if you spin it around a point it looks the same. NB It does not have to be the same whatever angle you turn it through. It could require a certain angle. e.g. For a starfish if you turn it through a multiple of 72 degrees it will look the same.

Of course, in nature, this is all approximate.

Answer 2

bilateral symmetry --> a perfect heart shape, something that if you place a mirror at the line of symmetry you'll get the full pattern

radial symmetry-->when you cut an orange into 8 equal pieces with 4 cuts, and let them lie outwards like a sunflower, the pattern (each piece) is repeated along a Point of symmetry

Answer 3

radial symmetry: more than one axis of symmetry. star fish and coral are the only ones that come to mind. alot of plants exhibit radial symmetry. radial symmetry is ideal for stationary or very slow moving organisms, as it allows for more awareness in all 360 degrees. bilateral symmetry: only one axis of symmetry. most animals exhibit this and it is suited to organisms that move a lot because it allows much more focused sensory awareness.

Answer 4

Symmetry in biology is the balanced distribution of duplicate body parts or shapes. The body plans of most multicellular organisms exhibit some form of symmetry, either radial symmetry or bilateral symmetry. A small minority exhibit no symmetry (are asymmetric).

In nature and biology, symmetry is approximate. For example, plant leaves, while considered symmetric, will rarely match up exactly when folded in half.

[edit] Radial symmetry
Radial symmetry
These organisms resemble a pie where several cutting planes produce roughly identical pieces. An organism with radial symmetry exhibits no left or right sides. They have a top and a bottom (dorsal and ventral surface) only.


[edit] Animals
Most radially symmetric animals are symmetrical about an axis extending from the center of the oral surface, which contains the mouth, to the center of the opposite, or aboral, end. This type of symmetry is especially suitable for sessile animals such as the sea anemone, floating animals such as jellyfish, and slow moving organisms such as sea stars (see special forms of radial symmetry). Animals in the phyla cnidaria and echinodermata exhibit radial symmetry.


[edit] Plants
Many flowers, such as buttercupss and daffodils, are radially symmetric (also known as actinomorphic). Roughly identical petals, sepals, and stamen occur at regular intervals around the center of the flower.





[edit] Special forms of radial symmetry

[edit] Tetramerism
Many jellyfish have four radial canals and thus exhibit tetramerous radial symmetry


[edit] Pentamerism
This variant of radial symmetry (also called pentaradial and pentagonal symmetry) arranges roughly equal parts around a central axis at orientations of 72° apart.

Animals
Members of the phyla echinodermata (like starfish) arrange parts around the axis of theforms. Examples include the Pentaspheridae, the Pentinastrum group of general in the Euchitoniidae, and Cicorrhegma (Circoporidae).

Plants
Flowering plants demonstrate symmetry of five more frequently than any other form.

Around 1510–1516 A.D., Leonardo da Vinci determined that in many plants a sixth leaf stands above the first. This arrangement later became known as 2/5 phyllotaxy, a system where repetitions of five leaves occur in two turns of the axis. This is the most common of all patterns of leaf arrangement.


[edit] Bilateral symmetry
Bilateral symmetryIn bilateral symmetry (also called plane symmetry), only one plane, called the sagittal plane, will divide an organism into roughly mirror image halves (with respect to external appearance only). Thus there is approximate reflection symmetry. Often the two halves can meaningfully be referred to as the right and left halves, e.g. in the case of an animal with a main direction of motion in the plane of symmetry.


[edit] Animals
Most animals are bilaterally symmetric, including humans (see also facial symmetry), and belong to the group Bilateria. The oldest known bilateral animal is the Vernanimalcula.

Bilateral symmetry permits streamlining, favors the formation of a central nerve center, contributes to cephalization, and promotes actively moving organisms. Bilateral symmetry is an aspect of both chordates and vertebrates.


[edit] Plants
Flowers such as orchids and sweet peas are bilaterally symmetrical (also known as zygomorphic). The leaves of most plants are also bilaterally symmetrical.


[edit] Asymmetry
The notable exception among animals are the Porifera (sponges) which have no symmetry

Answer 5

Threre is not way to place a diagram in these answers. Radial basically means Round. Bilateral means two sided.

Answer 6

I'm not going to completely do your homework for you but here is an idea: bi-lateral is like you, your left and right sides are symetric (like mirror images of each other (note: you are not exactly symetric but, close enough). Radial symetry is like a tire, if you put a point in the center of the tire (at it's axis), it is the same in any direction about that point (think of what it looks like if you spin the tire). Hope this helps.

Answer 7

In a bilaterally symmetrical form (a lobster or mammal), there is one specific line along which it can be cut to form two mirror image halves. In a radially symmetrical form (a jellyfish or sea urchin) there are an infinite number of lines along which it can be cut into two mirror image halves.

Answer 8

Radial symmetry means that an animal can be cut into 2 equal halves along any plane passing through their longitudinal body axis while a bilateraly symmetrical orga.can be cut into 2 halves only along their longitudinal body axis plane

Answer 9

no! draw your own diagrams.

Radial symmetry: you can spin it and it doesn't look any different. You could make it on a lathe.

Bilateral symmetry: you can flip it either way and it doesn't look any different. You could make it by folding the workpiece, cutting, and unfolding it. You can't make it on a lathe.

Answer 10

bilateral is the symetry of two halves, radial is the symetry of a cirlular area. E.G. Bilateral = human body, Radial = A car tire rim.