Type specimen of class enteropneusta, Biology

Assignment Help:

Q. Type specimen of class enteropneusta?

Examine the specimen and note the following features:

1. Balanoglossus has a soft, elongated, worm-like body which has a ciliated surface.

2. Body length reaches 10-50 cms and is divided into short conical proboscis, , collar and long trunk.

3. Proboscis is cylindrical, tapering and muscular. Near the base is a proboscis pore which is the opening of the coelom (present within the proboscis) to the exterior.

4: Collar is a short, cylindrical, muscular band enclosing a pair of coelomic cavities (collar coelom). The collar opens by a pair of collar pores on the dorsal ; surface. The rim of the collar encloses the mouth which is permanently open. ,

5. The trunk is superficially ringed and divided into 3 parts (a) anterior branchiogenital part containing genital ridge that carry gonads. This part can , be demarcated from the outside as it has gill-slits but the contents cannot be seen without dissection. (b) hepatic region. (c) the posterior end which is the trunk region.

6. The mouth lies at the base of proboscis and is encircled by the edge of the collar.

7. In the hepatic region are present double rows of hepatic caeca.

8. Alimentary canal is straight and anus is at the end of the trunk. (Sexes are separate and fertilization is external. Development includes a free swimming pelagic larva called tornaria larva.)


Related Discussions:- Type specimen of class enteropneusta

Determine the term - coupling factors, Determine the term - coupling factor...

Determine the term - coupling factors The coupling factors, also called the F l ATPase, present on the inner mitochondrial membrane facing the matrix side, are a very complex a

Removal of impurities in water, Many common methods are employed for the re...

Many common methods are employed for the removal of impurities from water. Some of them are: Sedimentation Filtration Reverse osmosis Electro dialysis Aeration

Aerotolerant anaerobes, Aerotolerant anaerobes are incapable of aerobic res...

Aerotolerant anaerobes are incapable of aerobic respiration, but can nevertheless grow in the presence of air. Many lactic acid bacteria fall into this category. They can only gene

What is the basic structure of the hiv virus, What is the basic structure o...

What is the basic structure of the HIV virus? What is the function of the glycoproteins of its envelope? HIV is an RNA virus. In its core there are two strands of RNA and reve

Agro-industrial -cereal and gram by-products, Cereal and Gram By-Products ...

Cereal and Gram By-Products Agro-processing is now regarded as the sun rise sector in view of its large potential in maintaining the nutritional quality of processed feed resource

Explain electrocardiography, Explain electrocardiography? What is mean...

Explain electrocardiography? What is meant by P-Q interval and S -T interval in electrocardiography? Mention two medical applications of this method.

Phases divided photosynthesis, Q. What are the phases into which photosynth...

Q. What are the phases into which photosynthesis is divided? Photosynthesis is divided into the photochemical phase or light reactions and the chemical stage.

Light scattering, how does measurement of light scattering allows the growt...

how does measurement of light scattering allows the growth of cells to be monitored.

Why humans good epithelial surfaces for respiration, Why is the skin on wor...

Why is the skin on worms, the gills in fish, and the lungs in humans good epithelial surfaces for respiration. Be specific.

Bovine spongiform encephalopathy (bse), B o vi n e spongiform encephalo...

B o vi n e spongiform encephalopathy (BSE) Bovine spongiform encephalopathy (BSE) is a transmissible, neurodegenerative, fatal brain disease of cattle characterized by post

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