Chordata and its characteristics, Biology

Assignment Help:

Phylum Chordata-

Chordata name given by Balfour.

Herst put hemichordata into separate phylum. Lamarck gave the word tunicata & vertebrata.

Pisces classified by Romer. Amphibia classified by G.K. Noble.

There are 65,000 species of chordata.

Pisces is largest class, having 33,000 species. Amphibia is smallest class having 2500 species.

CHARACTERS OF CHORDATA -

1.      Total animals are 3-5% of animal kingdom. Notochord or chorda dorsalis present in any stage of life cycle.

2.      Gill slits present in any stage of life cycle. Nervous system is dorsal, single & hollow. Post anal tail present.

3.      Mouth after first segment. Anus before last segment.

4.      Liver is present. Heart is ventrally placed.

5.      Flow of blood on dorsal side, anterior to posterior. Flow of blood on ventral side, posterior to anteriror.

6.      R.B.C. present. Circulatory system closed. Alimentary canal is placed ventral to nerve cord.

7.      Symmetry bilateral. Organ system grade. Triploblastic animals. True coelomate. Enterocoelic

8.      Unisexual. Sexual reproduction present. Larvae generally absent.

9.      Power of regeneration less. Cold blooded / warm blooded.

10.     Portal system present.

629_chordata.png Chordata is divided into 2 parts -

1. Protochordata              2. Vertebrata

 

S.No.

Character

Protochordata

Vertebrata

 

1

 

2

3

4

5

6

 

Notochord or chorda dorsalis

 

Habitat

Feeding

Evolution

Size

Endostyle

 

Present in original form

 

Marine

Cilliary

Early

Small

Present

 

Converted into vertebral column & cranium

 

All habitats

May be

Late

Large

Thyroid gland present


Related Discussions:- Chordata and its characteristics

Explain precautions for gram staining of bacterial cultures, Explain Precau...

Explain Precautions for Gram Staining of Bacterial Cultures? 1. Heat fix the smear, otherwise cells would be washed off. 2. Fresh 24 hrs old culture should be used. Gram var

Specific guidelines for maintaining records of patients, Specific Guideline...

Specific Guidelines Physician's orders Each order should have the date and time it was written.  Some way of indicating which orders have been carried out is nece

Salivary analyse works on foods, Explain how salivary amylase works on food...

Explain how salivary amylase works on foods like crackers

Explain methods for coliform detection in water, Explain Methods for Colifo...

Explain Methods for Coliform Detection in Water? Sanitary condition of drinking water can be determined by counting the coliform bacteria. It is a reliable and reproducible ind

Mathematical and statistical challenges, Progress on these biological issue...

Progress on these biological issues needs both that more mathematics and statistics be brought to bear on them and that new mathematical and statistical tools be prepared. All the

Fast response - biological responses, Fast Response - Biological Responses ...

Fast Response - Biological Responses Some of the fast responses are discussed below: It was found that when mung bean root tips were kept in a specific solution (contain

Lymph, Why lymph is also called middle man of body

Why lymph is also called middle man of body

Blood pressure with the phenomena of systole and diastole, Q. What is the r...

Q. What is the relation between the maximum and the minimum blood pressure with the phenomena of systole and diastole? A minimum blood pressure is the pressure on the wall of t

Spiral cleavage - metazoa, Spiral Cleavage - Metazoa In Spiral Cleavag...

Spiral Cleavage - Metazoa In Spiral Cleavage, however, the third and fourth cleavage planes are oblique to the polar axis and the resulting blastomeres do not lie on top of on

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