TO DETERMINE THE SPECIES AREA CURVE FOR SAMPLING OF POPULATION BY QUADRATE

Aim of the experiment: to determine species area curve for sampling of population by quadrate method.

Requirements: quadrate of definite size, graph sheet, pencil, scale.

Theory:The minimum size of the quadrate is equally determined by the species area curve method. The size of the quadrate is very important as too small or too large quadrate may not be representative of the community.

Procedure: the procedure is to lay a quadrate of small area in the sampling plot and the occurrence of the number of the species is observed. The plotting area is independent varieties (X-axis) and the occurrence of number of species, then plotting the area as the dependent variable (Y-axis)

The minimum quadrate size can be determined then the curve takes a horizontal shape indicating that the species number does not increase. The point where the curve flattens is joined with the X-axis. To find out the minimum area corresponding to the occurrence of maximum number of species. This method is very convenient for vegetation and analysis or plant analysis.

a.       A quadrate of definite size is thrown randomly in the area provided for sampling of the species composition at different sites, all the different types of the species and their quantity. It determines the different species concept.

b.      Calculate the total number of individuals of a species and total number of quadrate of occurrence of a species.

c.       Calculate the total species types on each quadrate i.e. quadrate no and the new types of the species to the previous no. of quadrate.

d.      Now plot the species area curve on a graph paper.

Result: the minimum of the two quadrate are required for complete sampling of the given areas curve.

Aim: estimation of protein.

Method: blank standard test.

Principle:

Protein + Cu^{2+        alkaline medium}         Cu-Protein complex

Requirements: three test tubes, micropipette-20 micro liter and 100 micro liter, calorimeter, beaker, micro pipette tips,

Reagents:

Burette reagent, protein, standard, serum, distilled water.

The reagents contain:

1.        Copper sulphate solution (12 mmol)

2.        Potassium iodide ( 20 mmol)

3.        NaOH (600 mmol)

4.        Sodium potassium tartarate (32 mmol)

Procedure:

a.        Calorimeter was switched ON and left ON for 1 hour before the experiment.

b.        Three test tubes were taken and marked as B (blank), T(test tube), S (standard).

c.        Calibration of calorimeter: calorimeter was set to zero i.e. 100% transmittance by the blank solution. Blank solution is prepared by taking 1000 micro liter burette reagent and 20 micro liter of distilled water in test tube.

d.        Now 1000 micro liter of burette reagent was taken in test tube S and T.

e.        Then 20 micro liter of protein standard was added to s marked test tube and 20 micro liter of serum was added in T marked test tube by the help of micropipette.

f.         After mixing the contents of test tube properly, the test tubes were incubated at room temperature for five minutes.

g.        Now the absorbance of T and S test tube solution was measured.

	B	S	T
BIURETE READING	1000 µl	1000 µl	1000 µl
PROTEIN STANDARD	------	20 µl	------
SERUM	------	------	20 µl
DISTILLED WATER	20 µl	------	------

Observation:

Serial number	Absorbance of S	Absorbance of T
1	0.26	0.22
2	0.29	0.27
3	0.12	0.09
4	0.21	0.19
5	0.23	0.21

Calculations:

                                                =

                                                =

                                                =4.4 mg/dl

food chain

Food chain  

Concept:

The transfer of food from plant sources through a series of organisms form a chain called food chain.

Ex: phytoplankton àzooplanktonà small fishà large fishà man

The above food chain is observed in the Indian rivers.

Ex:  grasshopperà melanopusà bufoà a rattle snake

This food chain occurs in Indian pasture

The above two examples clearly show that the base of the food chain is formed by plant( autotrophs) which are grazed by herbivore; which are predated by carnivores; which may be further predated by another higher carnivores.

Food chain relationships are very complex, as one organism may act as a food source of many other organisms and so on. For ex: grass may be eaten by cattle, grasshopper, rabbits, etc…….each of these may be eaten various other carnivores such as snake, toads, birds, or hyenas.

Thus instead of a simple food chain a complex web like structure called food web exists in the environment. Thus plant occupies the first trophic level called producers. The plant grazers occupy the second position called the primary consumers. The flesh eaters are at the third position called secondary consumers. The next trophic level is called tertiary consumer………the different trophic level are arranged in form of a pyramid.

Charles Elton the distinguished British ecologist realized in 1927 that there must be a limit to the number of links in any food chain. He surveyed many ecosystems and concluded that number of trophic levels very rarely exceeds five because during energy transfer loss of energy takes place in form of heat.

Charles Elton suggested that a small ecosystem cannot have many tertiary consumers because only a small amount of energy reaches the top trophic level.

Types of food chain:

In nature three types of food chain operates in general.

1.   Grazing food chain: the food chain which is herbivore based and the herbivores are considered important consumers is called grazing food chain. Ex: food chain found in the grasslands and the aquatic ecosystems. In grass land ecosystem or the aquatic ecosystem usually up to 50% of primary production is grazed upon by the herbivores and the remaining 50% are consumed by the decomposers as dead organic matter.

2.   Detritus food chain: in a forest ecosystem the insects are usually the dominant primary consumers but they consume less than 10% of the net primary production and the rest 90% of the total food is later on is fed by the small detritus feeding animals such as oligochaetes, and other micro organisms such as protozoa etc…….the animals consume the food by digesting it partially or fully making organic materials available for bacterial and fungal attack. The microorganisms also act as food for other animals. This type of food chain is called detritus food chain.

3.   Parasitic food chain: There must be a limit to he direst grazing of the producers. Because there out grazing may deplete or reduce their productivity therefore besides the food chain a parasitic food chain may also operate in many ecosystem, although the energy passing may be negligible. A parasitic food chain involves a HOST-PARASITE-HYPERPARASITE KINKS.