Which of the following characteristics cannot be used in grouping and sub-grouping of organisms?
(i) Cells are prokaryotic or eukaryotic
(ii) Presence or absence of mitochondria
(iii) Number of cells in an organisms
(iv) Mode of nutrition
(v) Level of organisation in body
(vi) Organisms are nocturnal or diurnal
(vii) Organisms are oviparous or viviparous

Options

A. (i), (iii), (iv) and (v)
B. (ii), (vi) and (vii)
C. (iii) and (vii)
D. None of these

Explanation

To determine which characteristic cannot be used in grouping and sub-grouping of organisms, we will analyze each option one by one:

1. **Cells are prokaryotic or eukaryotic**: This characteristic is fundamental in classifying organisms. Prokaryotic cells lack a membrane-bound nucleus, while eukaryotic cells have one. Therefore, this characteristic can be used for grouping.

2. **Presence or absence of mitochondria**: Mitochondria are known as the powerhouse of the cell and are typically present in eukaryotic cells but absent in prokaryotic cells. Thus, this characteristic can also be used for grouping.

3. **Number of cells in an organism**: Organisms can be classified as unicellular (single-celled) or multicellular (many-celled). This characteristic is valid for grouping organisms.

4. **Mode of nutrition**: Organisms can be classified based on their mode of nutrition into autotrophic (self-feeding) and heterotrophic (dependent on others for food). This characteristic is also useful for grouping.

5. **Level of organization in the body**: Organisms can be classified based on their level of organization, such as cellular, tissue, organ, and system levels. This characteristic is applicable for grouping.

6. **Organisms are nocturnal or diurnal**: This characteristic refers to the activity patterns of organisms (active during night vs. day). While it can provide insights into behavior, it is not a fundamental characteristic for biological classification. Therefore, this characteristic is less useful for grouping.

7. **Organisms are oviparous or viviparous**: Oviparous organisms lay eggs, while viviparous organisms give birth to live young. This characteristic can be used for grouping organisms, particularly in the context of reproductive strategies.

After analyzing all the options, the characteristic that cannot be used in grouping and sub-grouping of organisms is:

**Answer**: (vi) Organisms are nocturnal or diurnal.