Q.Sponges are at cellular level of organization.Jusify the statement.
Ans:Sponges are multicellular but the cellular level of organization means they dont form organized tissues.Sponges do have specialized cells and there is cooperation and coordination among the cells but it is limited.
Sponges dont possess any structures that can be considered organs.For instance,stomachs,kidneys and so on.Instead,sponge cells of various types are responsible for bodily functions-the day to day activities that sustain life.
These cells are:
(here i just mention the names of cells bt in my notes i mentioned function of each briefly)
1.Pinacocytes
2.Choanocytes
3.Mesenchyme
4.Archaeocytes
5.Scleroblasts
6.Myocytes and porocytes.

Seniors,how many marks could i get out of 10marks?
Thanks.

Any body who is interested to participate in this???????

__________________
"Mind is everthing;what you think,you become". Budhha

Good but do add detail of their functions like you said.It seems short for 10 marks.
Those who are going for next attempt can participate in this thread especially discussing general questions,MCQs or anything that they may feel difficult.

Thanks a ton.
yeas dear i would add functions of each cell type.
And dear nobody is ready to participate.i dnt knw why????
Dear,i'll continue my exercise.you are requested to evaluate my answerz.
Thanks in anticipation.


Q.what is polymorphism?describe it with reference to coelentrates.

__________________
"Mind is everthing;what you think,you become". Budhha

The reason is that most of the aspirants are preparing from books/notes ,so its not possible to type that material here.


POLYMORPHISM IN COELENTERATES

Polymorphism in Coelenterate


POLYMORPHISM IN COELENTERATA

Q.Define polymorphism and explain it with reference to Coelentrata.
Ans:
Outline
1.polymorphism defined
2.phenomenon of polymorphism with in Coelentrates
3.Significance of polymorphism

1.Polymorphism defined:"polymorphism(poly=many and morph=form)may be defined as the representation of a single organism by more than one kind of individuals or zooids which differ in their anatomy and physiology"
2.Phenomenon of polymorphism in Coelentrates:
Coelentrates are noted for their polymorphism and the members in it perform different functions.Various degrees of polymorphism is found coelentrates bu Siphonophora show the highest degree of polymorphism which is not found in anywhere else in the animal kingdom.They may have three kinds of polypoid zooids and four types of medusiod zooids.
The polypoid zooids are as follows:
a.Gastrozooids:are tubular or saccular with a mouth and there may be one tentacle bearing a nuematcyst.They are for ingestion and digestion of liquid food.
b.Dactylozooids:are for defence and obtaining food.They are tubular with a long tentacle armed with batteries of nuematocysts.They are also called,palpons or feelers
c.Gonozooids:may be like gastrozooids.They are for reproduction purpose.
The medusoid zooids are as follows:
a.Pneumatophore:is a gas filled vesicle or bladder which functions as a float and helps in swimming.It shows great variation in its structure and size in different siphonophores.
b.Phyllozooids:are leaf life bracts or thick and gelatinous medusoids having a canal of the enteron.They are for protective and shield some zooids of a colony.
c.Nectophores:are bell shaped medusoids with a velum,radial canals and a circular canal.They have no mouth,manubrium and tentacles.It brings about locomotion of the colony by swimming.
d.Gonophores:occur singly or in clusters on blastostyles.They have a velum,canals and a manubrium which bears gonads.Gonophores are dioecious and produce germ cells for reproduction.
3.Significance of polymorphism:
Polymorphism is the combination of anatomically and physiologically different zooids in an invidividual.Therefore,this phenomenon is of great importance in many ways.But the important is that it is essentially phenomenon of division of labour in which different functions are performed by different members of the colony.
I'll draw the diagrams as well.

Dear KINDLY evalute and how many marks it deserves.

__________________
"Mind is everthing;what you think,you become". Budhha

i think most expected questions for css 2013:
Invertebrates
1:reproduction in protozoa
2:spicules in sponges
3:polymorphism in coelenterata
4:obelia life cycle with diagram
5:metamerism in annelids
6:arthropoda metamorphisis, repiratory sys, mouth parts of insect
7:parasitism in platyhelminthes: repeated every year...past paper trend
8:mollusca, shell, foot, torsion
9:echinodermata, watervascular sys and tube feet
i think preparin g these alll one can esaily attemp any two from invertebrate portion......my suggestions

Vertebrates
1:hemichordates characteristics and amphioxus
2:bird flight mechanism
3:types of eggs, types of cleavage
4:gastrulation in general, in frog and chick
5:scales in fishes
6:composition of blood, structure of bone
7:kidney and heat in vertebrates, comparative study
8:skin.... and other exoskeleton structures
may b i have left sum topics imp for 2013... so u can add more which didnt cum in 2012

section A of paper will be 4m these topics but section B is broad and ur suggested topics may not be enuf....well,good suggestion at all.

__________________
"Mind is everthing;what you think,you become". Budhha

for paper II
section A
all organelles in detail (one question must from dis section)
mitosis and meiosis
replication and translation...leave transcription coz it came last year
transport of carbon dioxide in blood...imp ..can be repeated
types of pigments..respiration process..
digestion , excretion


if u will do organelles at atleast ek question ho jaye ga ..thn for second question u can prepare other imp topics which didnt cum last year

Section B
fossils..evidences
law of segregation...law of independent inheritance
theory of darwin and theory of lamarck
speciation...variation
ecosystem ...pond ecosystem....every year question cums on it
biogeochemical cycles.....jo last year aye hain woh beshak na karna
mutation...
linkages

if u will prepare these topics atleast u will b able to attempt two questions easily