SUB.: Zoology

  1. Very short questions: –                                        (7 x1 = 7)
  1. Define ex – flagellation.

Ans- Sudden & violently formation of flagella from microgametocyte of Plasmodium in stomach of mosquito is called ex- flagellation.

2. Name the infective stage of Plasmodium.

Ans- Sporozoite is infective stage of Plasmodium.

3. Define Histology.

Ans- The branch of biology which deals all aspects of tissue is called histology.

4. Who coined the term “Biology”?

Ans- The term “Biology” is coined by Aristotle & Treviranus.

5.Define cyclosis.

Ans- The streaming movement of endoplasm of eukaryotic cell is called cyclosis.

6. Name the structure responsible to maintain shape of Paramoecium.

Ans- Pellicle or, Periplast is responsible to maintain shape of Paramoecium.

7. Define digenetic parasite.

Ans- The Parasite which requires two hosts of two different species to complete its life cycle is called digenetic Parasite.

  1. Short answer questions: – (5×3=15)

   8. Explain external structure of Paramoecium.

Ans- Paramoecium is unicellular animal & it is slipper shaped. So, it is commonly called slipper animalcule. Its structure is explained as follows:-

Fig – Paramoecium
  1. The anterior end is broad & rounded while the posterior end is more or less pointed.
  2. The upper dorsal or aboral surface is convex while the ventral or oral surface is concave & thicker.
  3. It has greatest diameter just behind the center of the body.
  4. The ventral surface or,oral groove which posteriorly leads to a deeper conical vestibule which in turn communicates with a buccal cavity having a basal mouth or, hypostome.
  5. The ectoplasm secretes colourless, thin, firm, elastic & hard membrane which covered the body is called pellicle or, periplast which is responsible for a definite & constant shape of the paramecium
  6. The surface of pellicle has a great number of polygonal or hexagonal areas bearing the opening of trichocyst.
  7. Each hexagonal areas has a central depression or circum ciliary space from which a cilium comes out.
  8. All cilia are equal in size except those of the posterior end which are longer and called caudal tuft.
  9. The cilia originate from the basal granules or kinetesomes. [cilia in length and 0.27 & in diameter, 10,000 – 14,000 in number]

 2. Write down any three scopes of Zoology.

Ans:- There are so many advantages or, scope of Zoology. Some of them are explained below:-

  1. Study of microbiology has helped us to control and cure diseases and improve the quality of life.
  2. Zoology helps us to meet our needs by utilizing resources available to us. E.g. increase of food production, control of pollution, control of population etc.
  3. Advance in our knowledge of medicine, surgery, different types of culture of plants and animals for human welfare etc.

3. Write down the measures taken by you to conserve environment or, earth.

Ans:- The measures taken by me to conserve environment or, earth are as follows:-

  1. Many plantations done by me.
  2. I use the amount of energy which is my minimum requirement.
  3. I use to conserve water.
  4. I don’t waste paper which helps to decrease the rate of deforestation.

4. Define osmoregulation. How it is done by paramecium.

Ans-  Osmoregulation: –

The biological process by which Water amount & salt is maintained in the body of an individual is called Osmoregulation.

Paramoecium balance or, maintain the amount of water & salt by contractile vacuole. It has two contractile vacuoles with central vacuole & radial canal.

Water along with salt & excretory Product of cytoplasm is diffused in radial canal of contractile vacuole. Radial canal pumps it into central vacuole & finally outside by the systole of central vacuole of Contractile vacuole.

 

5. Explain the gamogony of Plasmodium.

Ans:- Gamogony stands for sexual reproduction by formation of gametes.

Gamogony of Malarial Parasite

It takes place in Anopheles mosquito. It can be studied as under following heading:-

Formation of male gamete:- As microgametocyte enters in gut or, stomach of mosquito it undergoes ex – flagellation. Each and every flagella gets nucleus and separate itself as male gamete.

Formation of female gamete:- In the stomach of Mosquito macrogametocyte undergoes unequal mitosis. As a result a polar body and female gamete is formed. Female gamete forms cone of reception to receive male gamete for fertilization.

Fertlization:- Fusion of male gamete and female gamete is called fertilization.

Male gamete enters inside the female gamete through cone of reception and performs fertilization. As a result it forms a single cell with single nucleus called zygote.

       Now it enters into sporogony to reproduce.

  1. Long questions: –
  2. Define Schizogony. Explain the life cycle of Plasmodium in human being.

Ans:- See the notes of aseual reproduction of plasmodium in zoolgy XI course.

[8] b. Define conjugation. Explain the conjugation in paramecium. (Explanation is not required) [7.5]

 Ans:- See the notes of Conjugation in Paramoecium in zoolgy XI course. (Only diagram)