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……………………. Is a hair like projections sho...

……………………. Is a hair like projections shown by synergid, which guide the pollen tube towards the egg.

A

Egg Apparatus

B

Antipodal Cells

C

Filiform Apparatus

D

Secondary Nucleus

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Read the following paragraph and answer the following questions given below it : Construction of a compound microscope : (i) Acompound microscope consists of a metal tube fitted with two convex lenses at the two ends. These lenses are called the objective lens ( the lens directed towards the object ) and the eyepiece ( the lens directed towards the eye ). Both the lenses are small in size , but the cross section of the objective lens has a short focal length . the focal length of the eyepiece is more than that of the objective lens . (ii) The metal tube is mounted on a stand . thr principal axes of the objective lens and the eyepiece are along the same line . The distance between the object and objective lens can be changed with a screw . It is possible to change the distance between the objective lens and the eyepiece. Working : (i) The object to be observed is illuminated and placed in front of the objective lens. slightly beyond the focal length of the objective lens. it's real , inverted and enlarged image is formed by the objective lens on the other side. (ii) This intermediate image lies with in the focal length of the eyepiece. It serves as an object for the eyepiece. The eyepiece works as a simple microscope . the final image is virtual, highly enlarged and inverted with respect to the original object . It can be formed at the minimum distance of distinct vision from the eyepiece . The final image is observed by keeping the eye close to the eyepiece. Use: This microscope is used to observe blood cells , microorganisms , etc. State which distance is adjusted to observe the object with a compound microscope ?

Egg cell, Polar nuclei,Pollen tube, Antipodals

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Read the paragraph and answer the questions given below : Locomotion is considered as an important characteristics of the animals. However, animals belonging to Porifera are said to be sedentary. Every other phylum has typical locomotory organs. E.g. Nereis crawls with the help of parapodia, whereas earthworm buries in soil by setae. Spiders have four pairs of walking legs, crab has five while all insects have three pairs of walking legs. The walking legs are also called appendages. Starfish moves with the help of tube feet. Snails and bivalves use muscular foot for locomotion. Birds flying with their spread out wings and fish swimming with their fins, both have spindle-shaped body tapering at both the ends. While flying or swimming such body offers least resistance during locomotion. Mammals have two pairs of limbs while animals like snakes are limbless. Other animals belonging to the class of snakes also have very weak limbs.which make them creep on the ground. Answer the question: Which phylum has a characteristic of jointed appendages?

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Paragraph based Questions : Read the paragraph and answer the questions given below : Lady bug beetles are friends of farmers as the destroy harmful insects. It is a predatory insect which lives on biting worm, white fly worm, whit moth, flower insects and bread worms. It acts as natural insecticide for crops like maize, jawar, cotton, sugarcane, cereals, vegetables, fruit trees, etc. These are attractive red or yellow or grey coloured insects. Many species of this insect are, found in our farms. The lifecycle of this insect follows: eggs, larvae, cocoon & moth stages. The eggs , found in flutter. The larvae are grey in colour. Larvae and adults both live on sucking insects. Of which colour the lady bug beetles are?

CHETANA PUBLICATION-REPRODUCTION IN LOWER AND HIGHER PLANTS -Exercise
  1. How many mitotic divisions are required to produce a mature male gamet...

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  2. The stalk of the ovule is …………………

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  3. ……………………. Is a hair like projections shown by synergid, which guide th...

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  4. …………………….. Is a female gametophyle.

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  5. The type of pollination observed in Zostera and Vallisneria respective...

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  6. The bisexual flowers which do not open to favour autogamy are called …...

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  7. In Calotropis self-pollination is avoided by ……………

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  8. The number of meiotic divisions required to produce 200 seeds in a pea...

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  9. ……………. And ……… are two events of sexual reproduction in flowering plan...

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  10. Endosperm is ……………

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  11. Formation of fruit without fertilization is called ……….

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  12. In porogamy the pollen tube enters the ovule through ………….

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  13. Pollination through …………….. Is known as chiropterophily

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  14. Yeast propagates by ……………

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  15. The cross pollination within the same species is also called as …..

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  16. In Angiosperms free nuclear division compulsorily take place during ……...

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  17. In recently fertilized ovule the haploid, diploid and triploid conditi...

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  18. Describe the development of male gametophyte in Angiosperms.

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  19. Name the nuclei taking part in triple fusion.

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  20. State the type of endosperm found in Balsam seed.

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