Tag: caskets of life

Questions Related to caskets of life

Which is useful for the study of a typical plant cell?

biology caskets of life observation of cells observing cells cell as structural and functional unit

  1. Onion peel

  2. Onion leaves

  3. Onion root

  4. Onion fruit

Show answer
Correct Option: A
Explanation:

An onion is a multicellular (consisting of many cells) plant organism. As in all plant cells, the cell of an onion peel have all the key characteristics of the plant cells such as cell wall, nucleus towards the plasma membrane, prominent and large centrally located vacuole. The presence of a cell wall and a large vacuole are indicators that help identify plant cells, such as seen in the onion peel.

.......... is used as a colouring agent to colour the slide which is to be observed under the microscope.

biology caskets of life observation of cells observing cells cell as structural and functional unit

  1. Water

  2. Iodine solution

  3. Hydrogen peroxide

  4. Chlorine

Show answer
Correct Option: B
Explanation:
Gram staining is the method for the identification of bacteria in which iodine solution is used. Iodine solution is directly applied on specimens, or it can be diluted first. Iodine solution makes a complex with carbohydrate or starch in cell and thus become visible under the microscope due to dark colouration.

Onion cells and cheek cells are the examples of prokaryotic cell.

biology caskets of life observation of cells observing cells cell as structural and functional unit

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

Onion cell is a plant cell with a cell wall and a large vacuole. On the other hand, human cheek cell is an animal cell with a prominent nucleus. Onion cells are brick-like in shape while human cheek cells are rounded. Human cheek cells do not have a cell wall or a large vacuole. Onion cell is an example of plant eukaryotic cell and cheek cell is an example of an animal eukaryotic cell.

So, the correct answer is 'False'.

When a student observed a stomatal epidermal peel under the microscope, it appeared pinkish red.
The stain used was :

biology caskets of life observation of cells observing cells cell as structural and functional unit

  1. Iodine

  2. Methyl orange

  3. Safranin

  4. Methylene blue

Show answer
Correct Option: C
Explanation:

Safranin stains epidermal peel of leaf pinkish red in colour. Safranin is a biological stain used in histology and cytology. Safranin is used as a counterstain in some staining protocols, colouring all cell nuclei red. It can also be used for the detection of cartilage, mucin and mast cell granules.

Hence C is the correct option.

How is a bacterial cell different from an onion peel cell?

biology caskets of life observation of cells observing cells cell as structural and functional unit

  1. Bacterial cell- prokaryote, onion peel cell- eukaryote

  2. Onion peel cell- prokaryote, bacterial cell- eukaryote

  3. Bacterial cell- contains membranous organelles, onion peel cell- no membranous organelle

  4. None of these

Show answer
Correct Option: A
Explanation:

Bacterial cells are primitive cells hence, called as prokaryotic cells. They do not possess membrane bound organelles as mitochondria, lysosomes, etc. They also do not have well-defined membrane bound nucleus. 
Onion peel cell is an eukaryotic cell with well-defined membrane bound nucleus, membrane bound organelles as mitochondria, vacuole, etc. 

Temporary mount of a peel is made in :

biology caskets of life observation of cells observing cells cell as structural and functional unit

  1. Alcohol

  2. Water

  3. Glycerine

  4. Acetone

Show answer
Correct Option: C
Explanation:
Temporary mount of a leaf peel is used to observe stomata. Stomata are small openings found widely scattered on the epidermis of leaves and young stems.
Glycerine is a dehydrating agent. Once glycerine is added it forms a protective layer that keeps it moistened. It avoids the drying of the specimen. If staining is done after adding glycerine then the specimen will not be stained properly because the stain will be washed off with glycerine.
Hence C is the option. 

Temporary mount of a peel is made in :

biology caskets of life observation of cells observing cells cell as structural and functional unit

  1. Alcohol

  2. Water

  3. Glycerine

  4. Acetone

Show answer
Correct Option: C
Explanation:
Temporary mount of a leaf peel is used to observe stomata. Stomata are small openings found widely scattered on the epidermis of leaves and young stems.
Glycerine is a dehydrating agent. Once glycerine is added it forms a protective layer that keeps it moistened. It avoids the drying of the specimen. If staining is done after adding glycerine then the specimen will not be stained properly because the stain will be washed off with glycerine.

A well stained leaf peel preparation when focussed under high power of the microscope would
show :

biology caskets of life observation of cells observing cells cell as structural and functional unit

  1. epidermal cells, stomata and guard cells, each with one nucleus and many chloroplasts.

  2. epidermal cells, stomata and guard cells, each with many nuclei but one chloroplast.

  3. stomata and guard cells without nuclei or chloroplast.

  4. stomata but no guard cells or epidermal cells.

Show answer
Correct Option: A
Explanation:
A well-stained leaf peel shows nuclei in a high power microscope. The leaf peel possesses stomata, guard cells and epidermal cells. The nuclei are present in both epidermal and guard cells, but stomata do not possess any nucleus.
So A is the correct option. 

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

biology caskets of life observation of cells observing cells cell as structural and functional unit

  1. (a) (iii), (iv), (ii), (i)

  2. (b) (i), (ii), (iii), (iv)

  3. (c) (ii), (iii), (iv), (i)

  4. (d) (iii), (iv), (i), (ii)

Show answer
Correct Option: A

Which one of the following organisms is correctly matched with its three characteristics?

biology caskets of life observation of cells observing cells cell as structural and functional unit

  1. Onion: Bulb, Imbricate aestivation. Axile Placentation

  2. Maize, Closed vascular bundles, Scutellum

  3. Pea: $C _3$$ pathway, Endospermic, seed, Vexillary aestivation

  4. Tomato: Twisted aestivation, Axile placentation Berry

Show answer
Correct Option: A
Explanation:
Onion belongs to the family Liliaceae. It is a modified stem which is present in the underground, called bulb. It shows imbricate aestivation in perianth. The gynoecium is in axile placentation. The above characteristics are matched with the characteristics of onion. 

Hence, the correct answer is option A.