Bilateral - metazoa, Biology

Assignment Help:

Bilateral - Metazoa

Bilaterally symmetrical animals have the major axis running from head (anterior) to tail (posterior). They have a ventral (lower) and dorsal (upper) surface that are different from each other. They have only two sides that look alike, the right and left. The animal can be divided into just two identical halves through a plane which passes from anterior to posterior end. Almost all animals including human beings except for sponges, ctenophores and cnidarians show bilateral symmetry.

Adult echinoderms, though radially symmetrical (pentamerous) have larvae that are bilateral. This is because they have evolved from bilaterally symmetrical ancestors. In general, bilateral animals that adopt a sessile existence commonly exhibit a shift towards radial symmetry. The shift may be slight as in acorn barnacles where only protective circular wall plates are arranged radially or the shift may be profound as in the case of sea stars or starfishes. Bilateral animals are called Bilateria.


Related Discussions:- Bilateral - metazoa

Discuss fatty acid with free radical, Discuss fatty acid with free radical ...

Discuss fatty acid with free radical The hydrogen is removed from the fatty acid chain to yield a free radical. The removal of hydrogen takes place at the carbon atom next to t

What is the importance of vitamin A, What is the importance of vitamin A ...

What is the importance of vitamin A The importance of vitamin A is undisputable. You may already be aware about the functions/role of vitamin A in our body.  Vitamin A is absol

Explain in details class hirudenia - leeches, Explain in details Class Hiru...

Explain in details Class Hirudenia - Leeches? This group includes the leeches. Most leeches grow in tropical freshwater habitats, and are familiar to most people as bloodsucker

Criteria to complete evolutionary branch of vertebrates, What are the six c...

What are the six criteria used to build a complete evolutionary branch of vertebrates? Dichotomy in each of the six following criteria builds the vertebrate evolutionary branch

Explain about the niacin (nicotinic acid) deficiency, Explain about the Nia...

Explain about the Niacin (nicotinic acid) deficiency? Niacin (nicotinic acid) deficiency classically results in pellagva, which is a chronic wasting disease associated with a c

What is folic acid, What is folic acid? Why is the anemia caused by deficie...

What is folic acid? Why is the anemia caused by deficiency of folic acid known as megaloblastic anemia? The folic acid (when ionized it is known as folate) is a coenzyme that

What are the terms used in sterilization, Q. What are the terms used in ste...

Q. What are the terms used in sterilization? Sterilization: It is defined as freeing the object or substance from all life of any kind. It is defined alternatively as the

What are enantiomers, Enantiomers: Select one: a. Have the same molec...

Enantiomers: Select one: a. Have the same molecular weight b. Have the same connectivity c. Are mirror images d. Are non-superimposable e. All of the above

State the law of independent assortment, (a)State the law of independent as...

(a)State the law of independent assortment. (b )Using punnett square demonstrate the law of independent assortment in a dihybrid cross including two heterozygous parents.

Find the magnitude and direction of the net electric force, Three point cha...

Three point charges are located at the corners of an equilateral triangle as in the figure below. Find the magnitude and direction of the net electric force on the 1.40 µC charge.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd