Cycas

This plant is Cycas. It looks similar to a palm tree. These trees are very rare in number. However, they are available for sale in nearby plant nurseries. It grows very slowly. So the plant is costly to buy. 

Cycas is a gymnosperm. The gymnosperms are the plants in which ovules are not enclosed by an ovary wall. After fertilisation the seeds remain exposed and therefore these plants are called naked-seeded plants. The gymnosperms produce microspores and megaspores which are produced in microsporangia and megasporangia borne on the sporophylls. 

Experiment: To demonstrate endosmosis in raisins

This is an experiment to show endosmosis in raisins (or in gram seeds). It is a part of Class 12 Biology Practical work. It is one of the major experiments. It comes under Plant Physiology.  It is also a part of Class 11 minor experiment or for Spotting. A simplified version of the experiment for your Practical file is given below:                                                          

                                                     Experiment

Aim: To demonstrate endosmosis in raisins and find the percentage of water absorption. 

Principle: Water moves from its higher concentration to lower concentration. It can pass through a selectively permeable membrane like the plasma membrane of cells (osmosis).

Materials Required: A few raisins, digital weighing scale, beaker, water, blotting paper. 

Procedure:

1.     Take three or four raisins and weigh it on a digital weighing scale. Note the weight W₁.

2.     Soak them by putting them in a beaker filled with pure water.

3.     After two hours, take out the raisins and wipe them dry using a blotting paper.

4.     Weigh the raisins on the digital weighing scale. Note the weight W₂.

Observation:

After a period of time, the raisins absorb water and get swollen because of endosmosis.

Initial weight of raisins = W₁ = _________

Weight of swollen raisins = W₂ = _________

Weight of absorbed water = W₃ = W₂ – W₁ = __________

Percentage of water absorbed by raisins = (W₃/W₁)  x 100 = ________ %

Result:

Raisins exhibit endosmosis and absorb water when soaked in it.

The percentage of water absorption of the given sample of raisin = _______%

Biological Classification Worksheet

 

Class 11 Biology Classification, Worksheet              Name: ____________________

1. Arrange these groups in hierarchy:  [order, family, kingdom, domain, phylum, species, class, genus]

2. Name any one animal and its trinomial name.

    __________________________________

3. Write the zoological names of:

            1. Lion _____________________

            2. Tiger _____________________

            3. Leopard __________________

            4. Cat ______________________

4. Name two organisms that show:

    a. Asymmetry: _____________________

    b. Radial symmetry: ___________________

    c. Bilateral symmetry: _________________

    d: diplobasty : _______________________

    e. triploblasty: ______________________

    f. Segmentation: _____________________

 

5. Father of Biology: __________________

6. Father of Botany: __________________

7. Father of Zoology: _________________

8. Father of Modern Taxonomy __________

 

9. Match the columns A with B

 

 

 

 

                                           

PTO

1. Protozoans  are called unicellular as well as _____________________ organisms.

2. ________________ is a connecting link between plants and animals.

3. _________________ have porous body wall.

4. _______________ is a living fossil.

5. Who coined the term protozoa? __________________

 

6. Match columns A and B

	A 1.     Ascaris 2.     Balanoglossus 3.     Hydra 4.     Neris 5.     Pila 6.     Planaria 7.     Scorpion 8.     Spongilla 9.     Star Fish 10.            Trypnosoma		B 1.     Annelida 2.     Arthropoda 3.     Coelenterata 4.     Echinodermata 5.     Hemichordata 6.     Mollusca 7.     Nematheminthes 8.     Platyhelminthes 9.     Porifera 10.            Protozoa