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

What is low - density lipoprotein receptor pathway, Q. What is low - densit...

Q. What is low - density lipoprotein receptor pathway? Ans. The increasing cellular free cholesterol generated regulates the activities of two enzymes that are of crucial

Phylum annilida, how we attempt a question of phylum annilida in exam?

how we attempt a question of phylum annilida in exam?

Examine multiple variation parameters for a genomic region , Determine SNP ...

Determine SNP variation among the aligned DNAs for a genomic region.   See below for how to count SNP variation.  The output file (Your_name_snp.txt) should have two

What are complementary genes, What are complementary genes? Does this inher...

What are complementary genes? Does this inheritance pattern obey Mendel's second law? Complementary genes are the different genes that act together to determine a given phenoty

Eggs of insect, EGG S OF INSECT This eggs is centrolecithal and it is ...

EGG S OF INSECT This eggs is centrolecithal and it is elliptical. It diameter is 2-3 mm. It has two eggs membrane i.e. vitelline membrane and chitinous capsule. The chit

Zoonotic diseases, Zoonotic Diseases The term zoonosis (zoonoses, plura...

Zoonotic Diseases The term zoonosis (zoonoses, plural) was coined by Rudolf Virchow to describe the disease transmitted from animal to man and vice versa. Zoonoses have been de

Phylum labyrinthomorpha - protozoan, Phylum Labyrinthomorpha - Protozoan ...

Phylum Labyrinthomorpha - Protozoan Trophic stage, ectoplasmic network with spindle shaped or spherical nonamoeboid cells. Small group living on algae; mostly marine or estuar

Concentration gradient and passive and active transport, Q. What is the rel...

Q. What is the relationship between concentration gradient and passive and active transport? Passive transport is the movement of substances across membranes in favour of their

Implant exposure - implant surgery, Describe Implant exposure ? Sound su...

Describe Implant exposure ? Sound surgical principles to minimize the surgical exposure based on the access required should be employed. A series of surgical approaches to achie

Evolutionary Biology-Genetic Drift, Imagine a population evolving by geneti...

Imagine a population evolving by genetic drift in which the frequency of allele K is 0.65. What is the probability that at some point in the future allele K will drift to a frequen

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