Tag: unicellular and multicellular organisms

Questions Related to unicellular and multicellular organisms

Volumes of prokaryotic and eukaryotic cells are ........... respectively.

  1. $0.2-10\mu {m}^{3}$ and $1000-10000\mu {m}^{3}$

  2. $0.1-10\mu {m}^{3}$ and $100-1000\mu {m}^{3}$

  3. $0.1-5.0\mu {m}^{3}$ and $3-30\mu {m}^{3}$

  4. $0.1-1.0\mu {m}^{3}$ and $10-100\mu {m}^{3}$


Correct Option: A

A bacterium divides every 35 minutes . If a culture containing $ 10^5$ cell per ml is grown for 175 minutes. What will be the cell concentration per ml after 175 mts _______________.

  1. $32 \times 10^5$ cells

  2. $5 \times 10^5$ cells

  3. $35 \times 10^5$ cells

  4. $175 \times 10^5$ cells


Correct Option: A
Explanation:
It is given that a bacterium divides every 35 minutes,
At 0 minutes, the culture contains $ 10^5 $ cells/ml.
After 35 minutes, the culture will contain $ 2^1 \times 10^5 $ cells / ml
similarly, after 175 minutes, that is after 5 generations, the no. of cells
$ = 2^{5} \times 10^{5}$ cells/ml.
This is equal to $ 32 \times 10^{5} $ cell/ml
So, (A) is the correct answer.

Read the given statements and select the correct option.


(i) One maize root cell can give rise to more than 17,500 cells.
(ii) A cell in watermelon can increase in size upto 3,50,000 times.
(iii) The growth of pollen tube is measured in terms of length.
(iv) The growth of the leaf is measured in term of surface area.

  1. Statements (i) and (ii) are correct.

  2. Statements (iii) and (iv) are correct.

  3. Statements (i) and (iii) are correct.

  4. Statements (i), (ii), (iii) and (iv) are correct.


Correct Option: D
Explanation:

The root cells may give rise to more than 17,500 cells, the cells of the root undergo mitotic division in an arithmatic manner, where some of the dividing cells undergo differentiation while others continue to divide.

A water melon pulp contains about 90% of water, so the enormous increase in size of the cell is due to endosmosis.
The growth of the pollen tube is measures in $\mu$ meters
A leaf visually is a two dimensional structure hence it is measured in terms of surface area.
So, the correct answer is 'Statements (i), (ii), (iii) and (iv) are correct.'

The average volume of a eukaryotic cell is

  1. Between 1 $\mu \, m^3$ and 1,000 $\mu \, m^3$

  2. Between 100 $\mu \, m^3$ and 1,000 $\mu \, m^3$

  3. Between 10 $\mu \, m^3$ and 100 $\mu \, m^3$

  4. Generally greater than 10,000 $\mu \, m^3$


Correct Option: A
Explanation:

A cell of 1 μm^3 volume average to the maximum 1,000 μm^3 most highly expressed proteins in a cell.

So, the correct option is 'Between 1 μm^3 and 1,000 μm^3'.

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.