Tag: cell as structural and functional unit

Questions Related to cell as structural and functional unit

Peel should not be allowed to dry while observing under microscope beacuse

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

  1. It causes more stomata to open

  2. It causes closure of stomata

  3. It  results in increase in total number of stomata

  4. None of these

Show answer
Correct Option: D
Explanation:

The observation of the onion peel is to see the arrangement of the cells that are separated by the thin layer. In onion, the peel is taken out from the scaly leaves that do not perform photosynthesis. They perform the function of storage. So, they do not show the stomata or the chloroplast. After the removal, the peel is kept in water to avoid drying of the leaves.

Hence, the correct answer is 'None of the above'

Where do we generally mount the material on the slide?

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

  1. In the centre

  2. On left side of slide

  3. On right side of slide

  4. Both B and C

Show answer
Correct Option: A
Explanation:

The material which is mounted on the slide is usually of fluid consistency. So, to avoid its spilling from sides, it is mounted in the centre. Also, if it is mounted at left or right side, then under microscope the material is not seen clearly. Hence, usually material is mounted in the centre. 

Which of the following is the main difference between onion peel cells and human cheek cells?

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

  1. Presence of mitochondria in onion peel cells only

  2. Presence of cell wall in onion peel cells only

  3. Absence of plasma membrane in cheek cells

  4. Absence of endoplasmic reticulum

Show answer
Correct Option: B
Explanation:

All living things are composed of cells. They are the building blocks of all life. Cells come in many different shapes and have different functions. Plant and animal cells are different, too. The main difference between plant and animal cells is that plant cells have a cell wall on the outer layer, whereas animal cells only have a cell membrane. The cell wall is a protective layer outside the cell membrane that also provides support for the cell's structure.

Which material did you use in the laboratory to observe vacuoles?

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

  1. Rheo

  2. Betel

  3. Onion

  4. Torch cactus

Show answer
Correct Option: C
Explanation:

The onion peels were used to observe the vacuoles in the laboratory because the onion has scaly leaves that perform the function of storage of food and have a large vacuole present in their cells. 

Hence, the correct answer is 'Onion' 

Which of the following is not present in onion cell?

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

  1. Nucleus

  2. Chloroplast

  3. Cytoplasm

  4. Cell wall

Show answer
Correct Option: B
Explanation:

The clear epidermal cells exist in a single layer and do not contain chloroplasts, because the onion fruiting body (bulb) is used for storing energy, not photosynthesis. Each cell has a cell wall, cell membrane, cytoplasm, nucleus and a large vacuole. The nucleus is present at the periphery of the cytoplasm. The vacuole is prominent and present at the centre of the cell, surrounded by cytoplasm. 

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.