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

Define the indications for root-end resection apicoectomy, Define the Indic...

Define the Indications for Root-End Resection Apicoectomy a) Persistent..... "Exactly the SAME of Curettage except the biopsy. b) When the apical portion of the root canal s

What is the rule for the pairing of nitrogen-containing base, Q. What is th...

Q. What is the rule for the pairing of nitrogen-containing bases in the DNA molecule? And in the RNA? Is this the last question appropriate? The rule for the pairing of nitroge

Explain the type I diabetes mellitus, What the difference is between type I...

What the difference is between type I diabetes mellitus and type II diabetes mellitus? Type I diabetes, also called as juvenile diabetes, or insulin-dependent diabetes (this na

What is an osteoporosis, In detail , how does the body maintains the blood ...

In detail , how does the body maintains the blood calcium ion homeostasis ( including the description of negative feedback system, organs and hormones involved) What is osteoporosi

Protozoans - regeneration in invertebrates, Protozoans - Regeneration i...

Protozoans - Regeneration in Invertebrates Most single celled animals such as protists, i.e. protozoans, regenerate very well. If part of the cytoplasm is removed from the

Agro industrial-copper, Copper Copper is an essential trace element re...

Copper Copper is an essential trace element required for enzyme systems, iron metabolism, connective tissue metabolism, integrity of the central nervous and immune systems. Co

Sketch cis-trans isomer of the first molecule, Please help with the followi...

Please help with the following: a) Draw a diagram (showing all the C and H atoms, and their bonds) for a hydrocarbon with 5 carbons with a double bond between carbons 2 and 3.

Modification of trna, Transfer RNA molecules are notable for having general...

Transfer RNA molecules are notable for having generally nucleotides shown in the figure such as 1-methylguanosine (m1G), pseudouridine   (Ψ), dihydrouridine   (D), inosine (I) and

How are mutagenic agents relates cancer to populations, How are mutagenic a...

How are mutagenic agents related to cancer incidence in a population? Is cancer a disease transmitted to the individual offspring? An exposition of a population to mutagenic ag

Explain phylum arthropoda, Phylum Arthropoda : (8,00,000 to 10,00,000 spec...

Phylum Arthropoda : (8,00,000 to 10,00,000 species) They are known as 'jointed footed' animals. The appendages are paired, and jointed with chitinous exoskeleton, varied and wi

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