Tuesday, July 23, 2024
03:58 PM (GMT +5)

Go Back   CSS Forums > CSS Optional subjects > Group V > Zoology

Reply Share Thread: Submit Thread to Facebook Facebook     Submit Thread to Twitter Twitter     Submit Thread to Google+ Google+    
 
LinkBack Thread Tools Search this Thread
  #21  
Old Saturday, April 25, 2009
37th Common
Medal of Appreciation: Awarded to appreciate member's contribution on forum. (Academic and professional achievements do not make you eligible for this medal) - Issue reason: CSP Medal: Awarded to those Members of the forum who are serving CSP Officers - Issue reason: Diligent Service Medal: Awarded upon completion of 5 years of dedicated services and contribution to the community. - Issue reason:
 
Join Date: Mar 2006
Posts: 1,514
Thanks: 1,053
Thanked 1,681 Times in 873 Posts
AFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud of
Default Protozoan reproduction.

Protozoan reproduction.
Although i have given a link of rep in protozoa its not comprehensive.
the link i am mentioning now has both detailed description and diagrams of asexual and sexual reproduction.

Clich here

regards
Reply With Quote
The Following User Says Thank You to AFRMS For This Useful Post:
Shali (Thursday, October 08, 2009)
  #22  
Old Sunday, April 26, 2009
Senior Member
Medal of Appreciation: Awarded to appreciate member's contribution on forum. (Academic and professional achievements do not make you eligible for this medal) - Issue reason: Qualifier: Awarded to those Members who cleared css written examination - Issue reason: Css 2010
 
Join Date: Feb 2009
Location: Islamabad
Posts: 850
Thanks: 902
Thanked 1,291 Times in 524 Posts
Viceroy is a splendid one to beholdViceroy is a splendid one to beholdViceroy is a splendid one to beholdViceroy is a splendid one to beholdViceroy is a splendid one to beholdViceroy is a splendid one to behold
Default Zoology Glossary

A glossary of Zoology Terms, Click here

Hope it helps !
__________________
When you have to shoot, shoot. Don't talk. ~ The Good, The Bad, and the Ugly

Last edited by Viceroy; Sunday, April 26, 2009 at 10:25 AM.
Reply With Quote
The Following User Says Thank You to Viceroy For This Useful Post:
AFRMS (Sunday, April 26, 2009)
  #23  
Old Sunday, April 26, 2009
37th Common
Medal of Appreciation: Awarded to appreciate member's contribution on forum. (Academic and professional achievements do not make you eligible for this medal) - Issue reason: CSP Medal: Awarded to those Members of the forum who are serving CSP Officers - Issue reason: Diligent Service Medal: Awarded upon completion of 5 years of dedicated services and contribution to the community. - Issue reason:
 
Join Date: Mar 2006
Posts: 1,514
Thanks: 1,053
Thanked 1,681 Times in 873 Posts
AFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud of
Default Diagrams

Figures of Invertebrate phylums
you can also check the glossory.

Click here

Regards
Reply With Quote
The Following User Says Thank You to AFRMS For This Useful Post:
Viceroy (Sunday, April 26, 2009)
  #24  
Old Sunday, April 26, 2009
37th Common
Medal of Appreciation: Awarded to appreciate member's contribution on forum. (Academic and professional achievements do not make you eligible for this medal) - Issue reason: CSP Medal: Awarded to those Members of the forum who are serving CSP Officers - Issue reason: Diligent Service Medal: Awarded upon completion of 5 years of dedicated services and contribution to the community. - Issue reason:
 
Join Date: Mar 2006
Posts: 1,514
Thanks: 1,053
Thanked 1,681 Times in 873 Posts
AFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud of
Default Porifera.

All about Porifera.Its a 17 page presentation and easily downloaded.
And in the end the classification is also given.
With this most of the phylum porifera is complete now.

Click Here

Regards
Reply With Quote
  #25  
Old Monday, April 27, 2009
Lord AvaLon's Avatar
Senior Member
Medal of Appreciation: Awarded to appreciate member's contribution on forum. (Academic and professional achievements do not make you eligible for this medal) - Issue reason:
 
Join Date: Feb 2009
Location: Quetta
Posts: 277
Thanks: 169
Thanked 263 Times in 163 Posts
Lord AvaLon is a jewel in the roughLord AvaLon is a jewel in the roughLord AvaLon is a jewel in the rough
Default

@afrms

You mentioned in some of your post about a couple of articles published in Dawn. I tried to find that peculiar post but couldn't succeed. Would you please write again about the title and date on which they were printed?

Regards,
Reply With Quote
  #26  
Old Monday, April 27, 2009
Senior Member
Medal of Appreciation: Awarded to appreciate member's contribution on forum. (Academic and professional achievements do not make you eligible for this medal) - Issue reason: Qualifier: Awarded to those Members who cleared css written examination - Issue reason: Css 2010
 
Join Date: Feb 2009
Location: Islamabad
Posts: 850
Thanks: 902
Thanked 1,291 Times in 524 Posts
Viceroy is a splendid one to beholdViceroy is a splendid one to beholdViceroy is a splendid one to beholdViceroy is a splendid one to beholdViceroy is a splendid one to beholdViceroy is a splendid one to behold
Default

Quote:
Originally Posted by Lord AvaLon
@afrms

You mentioned in some of your post about a couple of articles published in Dawn. I tried to find that peculiar post but couldn't succeed. Would you please write again about the title and date on which they were printed?

Regards,

I think you are talking about post 3 in the thread linked here
__________________
When you have to shoot, shoot. Don't talk. ~ The Good, The Bad, and the Ugly
Reply With Quote
The Following 2 Users Say Thank You to Viceroy For This Useful Post:
AFRMS (Monday, April 27, 2009), Lord AvaLon (Monday, April 27, 2009)
  #27  
Old Monday, April 27, 2009
37th Common
Medal of Appreciation: Awarded to appreciate member's contribution on forum. (Academic and professional achievements do not make you eligible for this medal) - Issue reason: CSP Medal: Awarded to those Members of the forum who are serving CSP Officers - Issue reason: Diligent Service Medal: Awarded upon completion of 5 years of dedicated services and contribution to the community. - Issue reason:
 
Join Date: Mar 2006
Posts: 1,514
Thanks: 1,053
Thanked 1,681 Times in 873 Posts
AFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud of
Default

Quote:
Originally Posted by Lord AvaLon
@afrms

You mentioned in some of your post about a couple of articles published in Dawn. I tried to find that peculiar post but couldn't succeed. Would you please write again about the title and date on which they were printed?

Regards,
salam
Mohsin has mentioned the link.i was going through the Dawn news articles and found a good article on Irrigation System.
The title is "giving irrigation system a facelift" By bilal hassan.(economic and bsuiness reveiw,feb 16-22 P.III.
do check it might be helpful.
regards
Reply With Quote
The Following User Says Thank You to AFRMS For This Useful Post:
Lord AvaLon (Monday, April 27, 2009)
  #28  
Old Monday, April 27, 2009
Lord AvaLon's Avatar
Senior Member
Medal of Appreciation: Awarded to appreciate member's contribution on forum. (Academic and professional achievements do not make you eligible for this medal) - Issue reason:
 
Join Date: Feb 2009
Location: Quetta
Posts: 277
Thanks: 169
Thanked 263 Times in 163 Posts
Lord AvaLon is a jewel in the roughLord AvaLon is a jewel in the roughLord AvaLon is a jewel in the rough
Default

That was helpful afrms,
I request you to keep on pointing out the articles which appears important to you in anyway. Having the clippings would obviously help alot in the high times of exam.

Regards,
Reply With Quote
  #29  
Old Monday, April 27, 2009
37th Common
Medal of Appreciation: Awarded to appreciate member's contribution on forum. (Academic and professional achievements do not make you eligible for this medal) - Issue reason: CSP Medal: Awarded to those Members of the forum who are serving CSP Officers - Issue reason: Diligent Service Medal: Awarded upon completion of 5 years of dedicated services and contribution to the community. - Issue reason:
 
Join Date: Mar 2006
Posts: 1,514
Thanks: 1,053
Thanked 1,681 Times in 873 Posts
AFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud of
Default

Quote:
Originally Posted by Lord AvaLon
That was helpful afrms,
I request you to keep on pointing out the articles which appears important to you in anyway. Having the clippings would obviously help alot in the high times of exam.

Regards,
yes i will keep on doing that.so keep an eye.yes reading newspaper helps a lot i got 50 in current just by reading dawn and shahid books
Reply With Quote
  #30  
Old Monday, April 27, 2009
37th Common
Medal of Appreciation: Awarded to appreciate member's contribution on forum. (Academic and professional achievements do not make you eligible for this medal) - Issue reason: CSP Medal: Awarded to those Members of the forum who are serving CSP Officers - Issue reason: Diligent Service Medal: Awarded upon completion of 5 years of dedicated services and contribution to the community. - Issue reason:
 
Join Date: Mar 2006
Posts: 1,514
Thanks: 1,053
Thanked 1,681 Times in 873 Posts
AFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud ofAFRMS has much to be proud of
Default Phylum Coelenterata

Phylum Coelenterata

The radiate animals Phylum Coelenterata ( Cnidaria )


The Phylum Coelenterata includes the polyps, jellyfishes, sea anemones, and corals. All of these animals have a body wall consisting of two layers of cells, between which is a jellylike substance, the mesoglea. Within the body is a single gastrovascular cavity, or coelenteron. Because of the presence of two cellular layers, Coelenterates are side to have a tissue-level organization. They are also acoelomates; that is, they dont possess a second body cavity, the coelom .



Position in animal kingdom


Phylum Cnidaria are characterized by primary radial or biradial symmetry . Radial symmetry , in which the body parts are arranged concentrically around the oral-aboral axis , is particularly suitable for sessile or sedentary animals .

The phylum has not advanced generally beyond the tissue level of organization, although a few organs occur .


Biologic contributions



a. The phylum has developed two well-defined germ layers , ectoderm and endoderm ; a third , or mesodermal ,layer , which is derived embryologically from the ectoderm , is present in some . The body plan is saclike , and the body wall is composed of two distinct layers , epidermis and gastrodermis , derived from the ectoderm and endoderm , respectively . The gelatinous matrix , mesoglea , between these layers may be structureless , may contain a few cells and fibers , or may be composed largely of mesodermal connective tissue and muscle fibers .


b. An internal body cavity, the gastrovascular cavity , is lined by the gastrodermis and has a single opening , the mouth , which also serves as the anus .



c. Extracellular digestion occurs in the gastrovascular cavity , as does intracellular digestion in the gastrodermal cells .



d. Most radiates have tentacles , or extensible projections around the oral end , that aid in food capture .

e. The first true nerve cells ( protoneurons ) occur in the radiates , but the nerves are arranged as a nerve net , with no central nervous system .

f. Sense organs appear first in the radiates and include well-developed statocysts (organs of equilibrium ) and ocelli.

g. Locomotion in the free-moving forms is achieved either by muscular contractions . However the groups are still better adapted to floating or being carried by currents than to strong swimming .
h. Polymorphism (polyp stage and medusa stage ) in the cnidarians has widened their ecologic possibilities .

i. Some unique features are found in this phylum , such as nematocysts ( stinging organoids ) in Cnidarians .



characteristics



a. Entirely aquatic , some in fresh water but mostly marine

b. Radial symmetry or biradial symmetry around a longitudinal axis with oral and aboral ends ; no definite head

c. Two basic types of individuals: polyps and medusae

d. Exoskeleton or endoskeleton of chitinous, calcareous , or protein components in some

g. Special stinging cell organoids called nematocysts in either or both epidermis and gastrodermis ; nematocysts abundant on tentacles , where they may form batteries or rings

h. Nerve net with symmetric and asymmetric synapses; with some sensory organs; diffuse conduction





e. Body with two layers, epidermis and gastrodermis, with mesoglea ( diploblastic ) ; mesoglea with cells and connective tissue ( ectomesoderm ) in some ( triploblastic )

f. Gastrovascular cavity (often branched or divided with septa ) with a single opening that serves as both mouth and anus; extensible tentacles usually encircling the mouth or oral region

i. Reproduction by asexual budding ( in polyps ) or sexual reproduction by gametes ( in all medusae and some polyps ) ; sexual forms monoecious or dioecious ; planula larva ; holoblastic cleavage .

j. No excretory or respiratory systems

k. No coelomic cavity


Classification



a. Class Hydrozoa

This class includes the freshwater polyps , the small jellyfishes , the hydroid zoophytes, and a few stony corals .

b. Class Scyphozoa

Most of the large jellyfishes are placed in this class .

c. Class Anthozoa

In this class are included the sea anemones , and most of the stony and horny corals .


Class Hydrozoa



(1) Characteristics


a. solitary or colonial ;

b. asexual polyps and sexual medusae , although one type may be suppressed ;

c. hydranths with no mesenteries.

d. medusae ( when present ) with a velum;

e. both fresh-water and marine .



(2) Typical animal


Hydra

a. The structure of hydra ;

b. The physiological function of hydra ;

c. The life cycle of hydra .





Class Scyphozoa



(1) Characteristics of Class Scyphozoa


a. solitary ;

b. polyp stage reduced or absent ;

c. bell-shaped medusae without velum ;

d. gelatinous mesoglea much enlarged ;

e. margin of bell or umbrella typically with eight notches that are provided with sense organs ;

f. all marine



Typical animal

Aurelia aurita

a. The structure of Aurelia aurita

b. The life cycle of Aurelia aurita





Class Anthozoa



(1) characteristics


a. all polyps, no medusae ;

b. solitary or colonial ;

c. enteron subdivided by at least 8 mesenteries or septa bearing nematocysts;

d. gonads endodermal ;

e. all marine .



(2) Typical animal

sea-anemones



Metamorphosis


Generally, after swimming for a few hours to many days the planula attaches and develops into a polyp or polypoid form , which in colonial species subsequently gives rise to the colony .

In some hydroids the planula remains in the gonophore, developing into the tentaculate actinula larva which is liberated and creeps about . After attachment, it develops into a polyp . In many hydrozoans with no polypoid phase the planula develops into an actinula and then a medusa .

In most scyphozoans, after attachment, the planula develops into a polypoid scyphistoma, with a stalked trumpet-shaped body . At maturity, the scyphistoma produces a free-swimming medusa stage, the ephyra larva, by transverse fission or strobilization. Ephyrae may be produced singly or several at a time, and develop to adult medusae .

In zoantharian anthozoans, the planula does not attach but develops into an anemone-like Edwardsia larva, then the Halcampoides larva. After attachment, tentacles develop and the adult polyp form is attained.


Reproduction


There are both dioecious and hermaphroditic species .



Sexual reproduction



Asexual reproduction


Asexual reproduction is common, it may occur by :

a. budding ;

b. pedal laceration, e.g. in sea anemones ;

c. transverse fission, e.g. in the production of ephyrae by scyphistomae

d. longitudinal fission , e.g. in many sea anemones .



Polymorphism


In many cnidarians the life-cycle contains two morphologically dissimilar individuals , the pulp and the medusa . In colonial species, each of these types may occur in a number of different morphological forms , specialized to perform a particular function .

The main types of modified polyp are :

a. the gastrozooid ---- feeding polyp

b. the gonozooid ---- reproductive polyp

c. the dactylozooid ---- protective polyp , or tentaculozooid

a, b and c are found in hydrozoan colonies

d. the autozooid ---- feeding and reproductive polyp

e. the siphonozooid ---- current producing polyp

d, and e are found in some authozoan colonies

A colony may also bear medusoid forms in different stages of formation or degeneration, which may or may not be freed . Medusae may become modified as swimming bells, floats , protective bracts or phyllozooids, or gonophores which serve only for reproduction .





Phylum Ctenophora


About 100 species known . Ovoid forms measure up to about 5 cm , flattened forms may be up to 1 meter or more in length .


(1) Characteristics



a. symmetry biradial ; arrangement of internal canals and the position of the paired tentacles change the radial symmetry into a combination of the two ( radial + bilateral )

b. usually ellipsoidal or spherical in shape , with radially arranged rows of comb plates for swimming

c. Ectoderm , endoderm , and a mesoglea ( ectomesoderm ) with scattered cells and muscle fibers ; may be considered tripoblastic

d. Nematocysts absent ( except in one species ) , but adhesive cells ( colloblasts ) present

e. Digestive system consisting of mouth, pharynx , stomach , and a serious of canals

f. Nervous system consisting of a subepidermal plexus concentrated around the

mouth and beneath the comb plate rows; an aboral sense organ ( statocyst )

g. No polymorphism or attached stages

h. Reproduction monoecious, gonads ( endodermal origin ) on the walls of the digestive canals , which are under the rows of comb plates ; determinate cleavage ; cydippid larva

i. Luminescence common


Comparison with Cnidaria


A. Ctenophores resemble the cnidarians in the following ways:


a. Form of radial symmetry ; together with the cnidarians , they form the group Radiata

b. Aboral - oral axis around which the parts are arranged

c. Well - developed gelatinous ectomesoderm

d. No coelomic cavity

e. Diffuse nerve plexus

f. Lack of organ systems



B. They differ from the cnidarians in the following ways:


a. No nematocysts except in Euchlora

b. Development of muscle cells from mesenchyme

c. Presence of comb plates and colloblasts

d. Mosaic, or determinate type of development

e. Presence of pharynx generally

f. No polymorphism


Classification


Class Tentaculata



With tentacles. Tentacles may or may not have sheaths into which they retract . Some types flattened for creeping ; other compressed to a bandlike form . In some the comb plates may be confined to the larval form.

Class Nuda



Without tentacles; conical form; wide mouth and pharynx; gastrovascular canals much branched .









Reply With Quote
The Following 2 Users Say Thank You to AFRMS For This Useful Post:
dr.atifrana (Thursday, April 30, 2009), Shali (Thursday, October 08, 2009)
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Very Important : How to Prepare Study Notes Shaa-Baaz Tips and Experience Sharing 5 Sunday, May 21, 2017 08:30 PM
Effective Study Skills Sureshlasi Tips and Experience Sharing 1 Friday, November 16, 2007 09:28 AM
Regarding Notes Anonymous84 Tips and Experience Sharing 1 Wednesday, August 15, 2007 06:56 PM


CSS Forum on Facebook Follow CSS Forum on Twitter

Disclaimer: All messages made available as part of this discussion group (including any bulletin boards and chat rooms) and any opinions, advice, statements or other information contained in any messages posted or transmitted by any third party are the responsibility of the author of that message and not of CSSForum.com.pk (unless CSSForum.com.pk is specifically identified as the author of the message). The fact that a particular message is posted on or transmitted using this web site does not mean that CSSForum has endorsed that message in any way or verified the accuracy, completeness or usefulness of any message. We encourage visitors to the forum to report any objectionable message in site feedback. This forum is not monitored 24/7.

Sponsors: ArgusVision   vBulletin, Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.