Tag: cell parameters

Questions Related to cell parameters

A cell weighing 1 mg grows to double its initial mass before dividing into two daughter cells of equal mass. Assuming no death, at the end of 100 divisions what will be the ratio of the mass of the entire populations of these cells to that of the mass of the Earth? Assume that mass of the Earth is $10^{24}Kg$ and $2^{10}$ is approximately equal to $1000$.

  1. $10^{-28}$

  2. $10^{-3}$

  3. $1$

  4. $10^3$


Correct Option: D

Hybridoma cells are

  1. nervous cells of frog

  2. hybrid cells resulting from myeloma cells

  3. only cells having oncogenes

  4. product of spore formation in bacteria.


Correct Option: B

Efficient large-sized cells are

  1. Elongated

  2. Elongated or branched

  3. With large surface area

  4. Having microvilli


Correct Option: A
Explanation:

  • Generally, cells are small so they can have an efficient surface area to volume ratio. Cells are so small so they can diffuse faster and all their processes will be a lot faster because of the smaller size of the cell.
  • For the large sized cells to become Efficient the cells must be elongated in order to have an efficient surface area to volume ratio.
  • Hence efficient large-sized cells are elongated.
  • So, the correct answer is 'Elongated'.
  • Which of following organisms can be seen only under the microscope?

    1. Unicellular

    2. Multicellular

    3. Vertebrates

    4. All of the above


    Correct Option: A
    Explanation:
    • Most unicellular organisms are of microscopic size and are thus classified as microorganisms, for example, Phytoplankton and protozoa range from about 0.001 mm to about 0.25 mm.
    • Most of the multicellular organisms and vertebrates are visible to the naked eye, which means that it is possible to view them without using the microscope.
      So, option A is the correct answer.

    The smallest human cell is

    1. Erythrocyte

    2. Kidney cell

    3. Liver cell

    4. Sperm


    Correct Option: A
    Explanation:

  • Erythrocytes or red blood cells (RBC) are the most abundant of all the cells in the blood. A healthy adult man has, on an average, 5 million to 5.5 millions of RBCs mm–3 of blood. It is Biconcave in size.
  • A typical human red blood cell has a disk diameter of approximately 6.2–8.2 µm and a thickness at the thickest point of 2–2.5 µm and a minimum thickness in the centre of 0.8–1 µm, being much smaller than most other human cells. Hence The smallest human cell is  Erythrocyte.
  • So, the correct answer is 'Erythrocyte'.
  • Longest cell in human body may be_____________.

    1. Nerve cell

    2. Leg muscle cell

    3. Bone cell

    4. Heart muscle cell


    Correct Option: A
    Explanation:

    A neuron is a nerve cell that is the basic building block of the nervous system. Neurons are similar to other cells in the human body in a number of ways, but there is one key difference between neurons and other cells. Neurons are specialized to transmit information throughout the body. Nerve cell or neuron possess a cell body with a long, thin hair like axon. A nerve cell can be up to a metre long. 

    Correct arrangement of the following in increasing size is
    (i) Width of biological membrane.
    (ii) Diameter of E.coli DNA
    (iii) Human ribosome
    (iv) Length of E.coli DNA
    (v) Diameter of human liver cell.

    1. i, iii, ii, iv, v

    2. ii, i, iii, iv, v

    3. i, iii, ii, v, iv

    4. ii, iii, i, iv, v


    Correct Option: C
    Explanation:

    Answer :
    i) Biological Membranes are typically 7.5–10 nm in thickness with two regular layers of lipid molecules.
    ii) E coli cells are typically rod-shaped, and are about 2.0 μm long and 0.25–1.0 μm in diameter.
    iii) Prokaryotic ribosomes are around 20 nm in diameter.
    iv) E.coli chromosomes have about 4.7 x 10^6 base pairs which results in a length of 1.6 mm.
    v) Diameter of human liver cell 50–100µm
    So correct answer is option C. i, iii, ii, v, iv.

    Which of the following cells are round and biconcave in shape?

    1. White blood cells

    2. Red blood cells

    3. Columnar epithelial cells

    4. Nerve cells

    5. Mesophyll cells


    Correct Option: B
    Explanation:
    • An erythrocyte is a cell containing large amounts of hemoglobin and specialized for oxygen transport. In mammals, erythrocytes are round and biconcave in shape. 
    • They are devoid of nucleus and other membrane-bound organelles. They derive energy through glycolysis and serve as tiny packets of hemoglobin.