Observing cells - class-VI
Laboratory techniques for observing cells under microscope, including slide preparation, staining, and comparing plant and animal cell structures
Questions
Peel should not be allowed to dry while observing under microscope beacuse
- It causes more stomata to open
- It causes closure of stomata
- It results in increase in total number of stomata
- None of these
Where do we generally mount the material on the slide?
- In the centre
- On left side of slide
- On right side of slide
- Both B and C
Which of the following is the main difference between onion peel cells and human cheek cells?
- Presence of mitochondria in onion peel cells only
- Presence of cell wall in onion peel cells only
- Absence of plasma membrane in cheek cells
- Absence of endoplasmic reticulum
Which material did you use in the laboratory to observe vacuoles?
- Rheo
- Betel
- Onion
- Torch cactus
Which of the following is not present in onion cell?
- Nucleus
- Chloroplast
- Cytoplasm
- Cell wall
Which is useful for the study of a typical plant cell?
- Onion peel
- Onion leaves
- Onion root
- Onion fruit
.......... is used as a colouring agent to colour the slide which is to be observed under the microscope.
- Water
- Iodine solution
- Hydrogen peroxide
- Chlorine
Onion cells and cheek cells are the examples of prokaryotic cell.
- True
- False
When a student observed a stomatal epidermal peel under the microscope, it appeared pinkish red.
The stain used was :
- Iodine
- Methyl orange
- Safranin
- Methylene blue
How is a bacterial cell different from an onion peel cell?
- Bacterial cell- prokaryote, onion peel cell- eukaryote
- Onion peel cell- prokaryote, bacterial cell- eukaryote
- Bacterial cell- contains membranous organelles, onion peel cell- no membranous organelle
- None of these
Temporary mount of a peel is made in :
- Alcohol
- Water
- Glycerine
- Acetone
Temporary mount of a peel is made in :
- Alcohol
- Water
- Glycerine
- Acetone
A well stained leaf peel preparation when focussed under high power of the microscope would
show :
- epidermal cells, stomata and guard cells, each with one nucleus and many chloroplasts.
- epidermal cells, stomata and guard cells, each with many nuclei but one chloroplast.
- stomata and guard cells without nuclei or chloroplast.
- stomata but no guard cells or epidermal cells.
Given below are the steps in the preparation of a temporary mount of a stained leaf peel.
(i) Cover the material with the cover slip
(ii) Transfer the stained peel to a clean glass slide and add a drop of glycerine
(iii) Remove the peel from lower surface of leaf
(iv) Drop it in water in Petri dish and add a drop of safranin stain.
The correct sequence of the experiment steps is
- (a) (iii), (iv), (ii), (i)
- (b) (i), (ii), (iii), (iv)
- (c) (ii), (iii), (iv), (i)
- (d) (iii), (iv), (i), (ii)
To distinguish microscopically between cheek cell and onion cell mount, one should look for the presence or absence of
- Mitochondria
- Plastids
- Cell membrane
- Nucleus
Geeta was asked to prepare a temporary mount of onion peel and list the steps. While writing, she wrote the following steps, which may not be in proper sequence. The correct sequence would be
(i) Add a few drops of safranin stain and transfer to a slide.
(ii) Cover it with a coverslip.
(iii) Add a drop of glycerine.
(iv) Take out onion peel.
(v) Keep the peel in water in a petri dish.
- i, ii, iii, iv, v
- iv, v, iii, ii, i
- iv, v, i, iii, ii
- v, iv, i, iii, ii
Why is glycerine used for preparing a temporary mount?
- Glycerine is isotonic to the cell sap
- It avoids drying of the material
- Both A and B
- None of the above