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

Explain the dark adaptation of vitamin a, Explain the Dark Adaptation of Vi...

Explain the Dark Adaptation of Vitamin A? In the early stages of VAD, the individual cannot see objects in dim light. This' phenomenon is used as a criterion for assessment in

List the major chemical changes occurring in food, Q. List the major chemic...

Q. List the major chemical changes occurring in food? The major chemical changes occurring in food are lipid oxidation leading to rancidity, loss of vitamins and degradation

Where can rna are found within cells, Q. Where can RNA are found within cel...

Q. Where can RNA are found within cells? In the eukaryote cell nucleus the RNA can be found to dispersed in the nuclear fluid, along with the DNA, and as the main constituent o

Compound feed prepration, Compound feed prepration The compounding of anim...

Compound feed prepration The compounding of animal feed involves processing and blending of raw feed ingredients of wide ranging physical, chemical and nutritional composition int

What are the symptoms of diabetes, What are the symptoms of diabetes H...

What are the symptoms of diabetes Healthy Person P takes a drug that produces a strong effect on the epithelial cells of the kidney collecting duct within one hour and lasts f

Explain about the forces acting on a gravity retaining wall, Explain about ...

Explain about the forces acting on a gravity retaining wall. Forces Acting on a Gravity Retaining Wall: In a general way the forces that act on a gravity retaining wall. The

Characterstics of cleavage, CHARACTERSTICS OF CLEAVAGE - In cleavage...

CHARACTERSTICS OF CLEAVAGE - In cleavage involve the series of mitotic division, so daughter cells are genetically similar to the parental cell. The resulting cells are c

MOVE MENT.., difference btn massflow and pressure law

difference btn massflow and pressure law

What is specific defence mechanism, What is Specific defence mechanism ...

What is Specific defence mechanism Specific:  These relate to specialized cells located throughout the  body which respond to invasion of foreign materials/microorganisms  su

Why meat and poultry are important for human body, Why Meat and Poultry are...

Why Meat and Poultry are important for human body? Meat and poultry are rich sources of proteins of high biological value. They do not contain carbohydrates. All

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