Tag: cell as structural and functional unit

Questions Related to cell as structural and functional unit

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.

To distinguish microscopically between cheek cell and onion cell mount, one should look for the presence or absence of 

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

  1. Mitochondria

  2. Plastids

  3. Cell membrane

  4. Nucleus

Show answer
Correct Option: B
Explanation:

Plastids are double membrane bound organelles found inside plants and some algae, which are primarily responsible for activities related to making and storing food. Many plastids are photosynthetic but some are not.

Therefore, to differentiate between a plant and an animal cell under a microscope, one must look for the presence of plastids.

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.

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

  1. i, ii, iii, iv, v

  2. iv, v, iii, ii, i

  3. iv, v, i, iii, ii

  4. v, iv, i, iii, ii

Show answer
Correct Option: C
Explanation:

Initially, onion peel has to be taken out.
Then, keep the onion peel in water in a petridish. This will remove the impurities sticked to onion peel. 
Then, add a few drops of safranine stain and transfer to a slide.
Then, add a drop of glycerine on onion peel. This step prevents the peel from drying out. 
Then, cover it with a cover slip for observing it under the microscope and to study the cell pattern. 

Why is glycerine used for preparing a temporary mount?

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

  1. Glycerine is isotonic to the cell sap

  2. It avoids drying of the material

  3. Both A and B

  4. None of the above

Show answer
Correct Option: C
Explanation:

Glycerine is isotonic to the cell sap. Due to this, cells used for mount will not shrink or swell and can be seen in their natural form. Also, glycerine makes the mounted material moist and prevents it from drying out. 

Match the following.

Column I Column II
A. Bacteria 1. Synthesis and storage of lipids
B. Sphaerosomes   2. Idiogram
C. Chloroplasts 3. Glycocalyx
D. Karyotype 4. Thylakoids

biology cell and cell organelles cell membrane and cell wall cell wall cell division in embryo development component of the cell cell organelles cell: the unit of life cell as structural and functional unit basics of cell

  1. A-3, B-2, C-4, D-1

  2. A-3, B-1, C-2, D-4

  3. A-4, B-3, C-2, D-1

  4. A-1, B-2, C-3, D-4

  5. A-3, B-1, C-4, D-2

Show answer
Correct Option: E
Explanation:

Sphaerosomes are single half unit membrane covered small spherical organelles which synthesize and store fats. The cell wall of bacteria is made up of glycocalyx (carbohydrate and amino acids). Chloroplasts are eukaryotic plant cell organelles which have an internal thylakoid membrane system. The thylakoid membranes carry out the light reactions part of photosynthesis. The chromosomes of a eukaryotic cells are called its karyotype. The diagrammatic representation of a cells karyotype is called an idiogram.

Plant cells can usually be distinguished from animals cells because only plant cells possess 

component of the cell cell and cell organelles cell organelles cell: the unit of life biology cell as structural and functional unit basics of cell

  1. Mitochondria and lysosomes

  2. Chromosomes and lysosomes

  3. Chloroplast and cell wall

  4. Chloroplast and Golgi complex

Show answer
Correct Option: C
Explanation:

Plants are autotrophic organisms which manufacture their own food. Plant cells have chlorophyll containing chloroplasts which are involved in the process of photosynthesis. A plant cell is surrounded by cellulosic cell wall which is dead at maturity. Chloroplasts and cellulosic cell wall are characteristics of plant cells only.