Wednesday, April 17, 2013

CBSE Class 9 - Science Practical - Experiment: To study temporary mount of onion peel.

Experiment: To study Temporary Mount of Onion Peel

Experiment: To study Temporary Mount of Onion Peel
image credits:openclipart
MCQs

Q1: Which cells can we see while observing the slide of onion peel?

(a) Epithelial cells
(b) Epidermal cells
(c) Parenchymatous cells
(d) nerve cells


Q2: Which stain is used while observing onion cells?

(a) Safranin
(b) Iodine solution
(c) Methylene blue
(d) Alician blue


Q3: Shape of onion cells is

(a) square
(b) circular
(c) elliptical
(d) rectangular



Q4: Some characteristics of onion peel cells are:
(a) Cell wall is present
(b) only one nucleus is present
(c) intercellular spaces are not there
(d) All of these


Q5: Coverslip should be gently placed on the slide to avoid:
(a) crushing of the material
(b) entry of air bubbles
(c) avoid oozing of stain
(d) breaking,as it is made of glass


Q6: The shape of nucleus in plant cells(onion peel) is generally:
(a) cylindrical
(b) spherical
(c) elliptical
(d) rectangular


Q7: The colour given by safranin to onion peel cell wall is:
(a) green
(b) black
(c) orange
(d) pinkish-red


Q8: To study onion peel cells,we take:
(a) green leaves of onion 
(b) crushed pulp of onion
(c) dry scale leaf of onion
(d) thin transparent peel from the ventral side of piece of onion


Q9: In the preparation of temporary mount of onion peel which of the following is not used :
(a) water
(b) glycerine
(c) safranin
(d) alcohol


Q10: The outermost layer in an onion cell as observed in the temporary mount of an onion peel is the
(a) plasma membrane
(b) cellulose
(c) cell wall
(d) cytoplasm



Watch the you tube video by ScienceProfOnline showing how to prepare wet mount microscope slide:



Answers:
1) (b) Epidermal cells
2) (a) Safranin
3) (d) rectangular
4) (d) All of these
5) (b) entry of air bubbles
6) (c) elliptical
7) (d) pinkish-red
8) (d) thin transparent peel from the ventral side of piece of onion
9) (d) alcohol
10) (c) cell wall

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