Biology · Science General

Cell Biology and Structure

3,062 Questions

Cell biology focuses on the structure and function of cellular organelles. Key topics include cellular respiration, DNA inheritance, and energy production. These fundamental biology concepts are crucial for medical entrance and state service examinations.

Cell organelles functionsCellular respiration sitesDNA and ribosomesAnimal cell structurePlant cell components

Cell Biology and Structure Questions

Multiple choice botany cell and cellular organization cell theory microscope cell and its discovery

Unstained living cells can be best studied by

  1. Phase contrast microscope

  2. Electron microscope

  3. Fluorescent microscope

  4. Polarising microscope
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Phase contrast microscopy is a type of microscopic technique which converts phase shifts in light passing through a transparent specimen to brightness changes in the image. This technique made possible to study living cells without staining.

Multiple choice botany cell and cellular organization cell theory microscope cell and its discovery

The distribution of two or more specific molecules within a cell can be studied by using

  1. Dark field microscope

  2. Fluorescent microscope

  3. Phase contrast microscope

  4. Interference contrast microscope
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The fluorescence microscope can localize and quantify specific molecules in the cells. It is the most versatile and powerful technique for localizing proteins within a cell by light microscopy, is fluorescent staining of cells and the observation in the fluorescence microscope.

Thus, the correct answer is option B.

Multiple choice botany cell and cellular organization cell theory microscope cell and its discovery

Which one of the following can be visualized under fluorescent microscope?

  1. Chloroplast

  2. Actin filaments

  3. Nucleus

  4. Both A and B
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Fluorescent microscope is a modification of ultraviolet microscope, which was made by Coons in 1945. The instrument uses long wave ultraviolet rays for illumination. It has complementary filters, which allow the viewer to observe directly with the eyes. The microscope is useful in detecting those components which show autofluorescence, e.g., chlorophylls, collagen fibrils, actin filaments, vitamin A, etc. Others can be made fluorescent by coating with fluorochrome dyes like acridine orange and coriphosphine and minerals, eg., proteins, lipids, starch, glycogen, cellulose, etc. The light emitted by them is red, orange, yellow, or green against dark field. It is called as secondary fluorescence. The technique is also useful in diagnosis of viruses, bacteria and protozoans. Immunofluorescent antibody labelling techniques is used in diagnosis of specific molecules like antigens and antibodies. it involves conjugating specific fluorochromes with specific antibodies.

Multiple choice botany cell and cellular organization cell theory microscope cell and its discovery

Fluorescent microscope is used

  1. To localize cell structure as chlorophyll stained with fluorochromes.

  2. To study living cells.

  3. To study smallest organelle.

  4. All of the above.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Fluorescent microscope is a modification of ultraviolet microscope which was made by Coons in 1945. The instrument uses long wave ultraviolet rays for illumination. It has complementary filters which allow the viewer to observe directly with the eyes. The microscope is useful in detecting those components which show autofluorescence eg. Chlorophylls, collagen fibrils, vitamin A etc.

So, the correct answer is 'To localize cell structure as chlorophyll stained with fluorochromes'.

Multiple choice botany cell and cellular organization cell theory microscope cell and its discovery

The distribution of two or more specific molecules within a cell can be studied by using 

  1. Dark field microscope

  2. Fluorescent microscope

  3. Phase contrast microscope

  4. Interference contrast microscope

  5. Bright field microscope
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Fluorescent microscope is useful in detecting those components which show autofluorescence, e.g., chlorophylls, collagen fibrils, vitamin A. Others can be made fluorescent by coating with fluorochrome dyes like acridine orange and coriphosphine. This is called as secondary fluorescence and is useful in detecting specific biomolecules.

Multiple choice botany cell and cellular organization cell theory microscope cell and its discovery

The part of a cell that can be seen with an electron microscope, but cannot with a light microscope is/are 

  1. Nucleus

  2. Golgi bodies

  3. Chloroplasts

  4. Membrane separating the nucleus from the cytoplasm
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Nucleus, Golgi bodies and chloroplasts are the organelles of the cell and hence can easily be visible under the compound microscope. The nuclear membrane is the membrane which separates the nucleus with the cytoplasm. It is a double lipid bilayer membrane which can only be visible under the electron microscope.
Thus, the correct answer is option (D), 'membrane separating the nucleus from the cytoplasm'.

Multiple choice botany cell and cellular organization cell theory microscope cell and its discovery

Study of cell structure under microscope is

  1. Cytology.

  2. Cell Biology.

  3. Cytochemistry.

  4. Microanatomy.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cell structure consists of the whole cell with the cell membrane, nucleus, ribosomes, Golgi bodies which are dispersed in the cytoplasm of a cell. So basically these are cytoplasmic structures which are so tiny that they can only be observed under the microscope. And study of these cells (both animal and plant) structures, functions and their chemistry under the microscope is called as cytology.

Multiple choice botany cell and cellular organization cell theory microscope cell and its discovery

Which one of the following microscopes can be used for studying unstained and dividing cells?

  1. Electron microscope

  2. Phase-contrast microscope

  3. Polarising microscope

  4. All the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Phase-contrast microscopy is specifically designed to visualize transparent specimens, such as unstained living cells, by converting phase shifts in light into brightness changes.

Multiple choice botany cell and cellular organization cell theory microscope cell and its discovery

A living cell can be best studied by the means of______________.

  1. Dark field microscope.

  2. Electron microscope.

  3. Phase-contrast microscope.

  4. Compound microscope.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Phase Contrast Microscope was developed by Zernike. The microscope has a phase plate and an annular diaphragm. They bring about changes in light rays passing through the specimen producing differences in light intensity. Denser parts alter path of light more than the thinner parts. This produces varying contrast for different regions. Hence, staining is not required and the difference between denser and lighter parts of the specimen is revealed by the phase difference. The microscope is useful in the study of small living organisms, living cells, constituents of living cells, effect of various factors over living structures, and study of various cellular events like behaviour of chromosomes during mitosis and meiosis, spindle formation, cytokinesis, pinocytosis, phagocytosis, cyclosis, glandular secretions, spermatogenesis, oogenesis etc.

So C is the correct option. 

Multiple choice botany cell and cellular organization cell theory microscope cell and its discovery

A living cell is to be studied without staining. A microcsope that can be used for this is

  1. Phase contrast microscope

  2. TEM

  3. SEM

  4. Fluorescent microscope
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Option $ -(A) $ Phase contrast microscope
It is an optical microscopy technique that converts phase shifts in light passing through a transparent specimen to brightness changes in the images.
Multiple choice botany cell and cellular organization cell theory microscope cell and its discovery

Distribution of two or more specific molecules within a cell is studied by _______________.

  1. Fluorescent microscope.

  2. Dark field microscope.

  3. Bright field microscope.

  4. Phase contrast microscope.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The fluorescence microscope can localize and quantify specific molecules in the cells. It is the most versatile and powerful technique for localizing proteins within a cell by light microscopy, is fluorescent staining of cells and the observation in the fluorescence microscope.
Thus, the correct answer is option A. 
Multiple choice

In normal plants cells there is a control center called the _____.

  1. Mitochondria

  2. Nucleus

  3. Vacuoles

  4. Cytoplasm
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The nucleus is the control center of the cell, housing the genetic material that directs cellular functions. Mitochondria produce energy, vacuoles store substances, and cytoplasm is the jelly-like substance filling the cell.

Multiple choice

Which is not a specialized parenchyma cell?

  1. Transfer Cell

  2. Sieve tube members

  3. Cholenchyma

  4. Vessel Members
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Vessel members are part of xylem tissue, not specialized parenchyma. Transfer cells are specialized parenchyma. Sieve tube members are phloem elements. Cholenchyma appears to be a misspelling but parenchyma-related.

Multiple choice

What is the equivalent to a companion cell in a pine tree?

  1. anchor cell

  2. albuminous cell

  3. who cell

  4. albumin cell
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In gymnosperms like pine trees, sieve cells are the equivalent of sieve tube members in angiosperms, and albuminous cells are the equivalent of companion cells.

Multiple choice

Tracheids are what kind of cells?

  1. Parenchyma

  2. Sclaryncyma

  3. Collenchyma
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Tracheids are elongated cells with thick lignified secondary walls that provide both structural support and water conduction in plants. They are a type of sclerenchyma tissue, which consists of dead cells with thick walls at maturity. Parenchyma cells are thin-walled and living, while collenchyma have unevenly thickened but unlignified walls.