All living organisms are made of chemicals which belong to various classes and have different sizes and functions. In the cells, these chemicals are constantly being made and changed into some other biomolecules. These conversions or chemical reactions taking place in the body are collectively known as metabolism. All plants, animals, fungi and microbes exhibit metabolism. Non-living objects do not exhibit metabolism. So we can say metabolism is a defining feature of all living organisms without exception.
Metabolic reactions can be demonstrated outside the body in a test-tube. A metabolic reaction preformed in a test-tube (in vitro) is neither living nor non-living but surely living reaction.

Nomenclature is a science of providing distinct and proper names to organism so that they can be easily recognized and differentiated from others. 

In trinomial nomenclature, the names of taxa have three parts. The first part is the name of genus, the second part is the name of species and third part is the name of subspecies. For example, <i>Brassica oleracea botrytis</i>.

So, the correct answer is 'Subspecies'.

In biology, trinomial nomenclature is used to name living things at a rank lower than species. The term trinomial nomenclature means "three-part name" or "system of three-part names". If living things r than species get a scientific name, each name has three parts. Binomial Nomenclature: Binomial nomenclature was given by carolus linnaecus in his tenth edition of system natura published in 1758. Binomial nomenclature is defined as system of nomenclature that denote species of living organism.

The skin of the frog has mucus, which makes the skin moist, smooth and slippery. The skin of the frog has the ability to absorb water.

It is dark green in color with irregular spots on the dorsal side, while in the ventral side; it is pale yellow in color. 

Biodiversity: The number and types of plants and animals that exist in a particular area.

 It is the existence of a wide variety of plant and animal species living in.

 Greater species diversity ensures natural sustainability for all life forms.

 It boosts ecosystem productivity where each species, no matter how small.

➧ Types of Biodiversity are:-
[1] Genetic Diversity:-

❱ The total number of genetic characteristics in the genetic makeup of a species. 

[2] Species  Diversity:-

❱ The number of different species that are represented in a given community.

[3] Ecosystem  Diversity:-

❱ The the variety of different ecosystems within an area.

Viruses :

1. They have a protein coat.
2. The genetic material may be either DNA or RNA.
3. They can infect plants, animals and bacteria.

Viroids :

1. They do not have a protein coat.
2. The genetic material is RNA.
3. They can infect only plants.

Viruses :

1. They have a protein coat.
2. The genetic material may be either DNA or RNA.
3. They can infect plants, animals and bacteria.

Viroids :

1. They do not have a protein coat.
2. The genetic material is RNA.
3. They can infect only plants.

naming or nomenclature we use today was introduced by Carolus Linnaeus in the eighteenth century. In Binomial nomenclature, the first name is the generic name beginning with a capital letter whereas the second name is the species name which begins with a small letter. Example – <i>Homo</i> <i>sapiens</i> where <i>Homo</i> is a genus name and <i>sapiens</i> is a species name.

Certain conventions are followed while writing the scientific names:

1.   The name of the genus begins with a capital letter.

2.   The name of the species begins with a small letter.

3.   When printed, the scientific name is given in italics.

4.   When written by hand, the genus name and the species name have to be underlined separately.

(a) To develop interest and awareness about wild animals in the public.
(b) The Zoos are involved in the conservation of many endangered species of wild life. To conserve the wild life, special attention is being given to the protection of natural habitats and ecosystems and the captive breeding of wild animals.

“Taxonomy is the study of principles and procedures of classification.”

Taxonomy includes study of following 4 points:

(1) Identification: Identification of living organisms

(2) Nomenclature: Nomenclature of living organisms

(3) Classification: Classification of living organisms in groups

(4) Affinities: Study of inter relationship between living organisms

It is the same

Taxon, plural Taxa, any unit used in the science of biological classification, or taxonomy. Taxa are arranged in a hierarchy from kingdom to subspecies, a given taxon ordinarily including several taxa of lower rank.

TAXON

Each unit or category of classification is termed as a taxon. It represents a rank. For example, the basic level of classification is species, followed by genus, family, order, class, phylum or division, in ascending order. The highest level of classification is known as kingdom.

1) Biodiversity- the variety of plants and animals life in a particular habitat, a high level of which is usually considered to be important and desirable.
2) Nomenclature- system of names/terms/ the rules for forming these terms in a particular field of arts or sciences.

Key is a taxonomical aid that helps in identification of plant and animal species. These keys are based on similarities and dissimilarities in characters, generally in a pair called couplet.

Each statement in a taxonomic key is referred to as a lead. For categorizing each taxonomic rank, such as family, genus, species, etc., different keys are used. It is also useful in identification of unknown organisms.

Keys are of two types- indented and bracketed keys. Indented key provides a sequence of choices between two or more statements while in bracketed key, a pair of contrasting characters are used.

It is our backbone which extends in the mid axis of the back (posterior) part of our trunk from head to the lower (inferior) extremity of trunk. Together with the sternum and rib, it forms the supporting frame work of our trunk. It support and rotate the head, suspends the viscera, protect vital organs, provides attachment to limb girdles, facilitates some movement of the trunk and houses the spinal cord. Vertebral column make two-fifth of total weight of body. The length of human vertebral column is 71 cm. (28 Inc.) in adult male and about. 61 cm (24 m) in an average adult female.

An aster is a cellular structure shaped like a star, consisting of a centrosome and its associated microtubules during the early stages of mitosis in an animal cell. Asters do not form during mitosis in plants. It is A star-shaped structure formed in the cytoplasm of an animal cell during mitosis, having raylike microtubules that surround the centrosome.

Common Fundamental characteristics are considered for the purpose of classification of animals.

If we consider specific characteristics, then each organism will be placed in a separate group and the entire objective of classification would not be achieved.

Classification of animals is also important in comparing different organisms and judging their individual evolutionary significance. If only a single characteristic is considered, then this objective would not be achieved.

Growth is defined as inversible increase in the number of cells or mass of living structure. If we consider increase in body mass at growth, non living objects like sand mounts grow too. Hence growth cannot be taken as a defining property if living organisms. Though it is a characteristics of living organisms . In case of non - living growth is external but in case of living growth is internal.

Reproduction :- Unicellular organisms reproduce by cell division. In multicellular organisms reproduction mostly refers to sexual reproduction and some of them reproduce asexually also. Reproduction cannot be considered an inclusive defining characteristics of living organisms of the following.
In single celled organism growth and reproduction are synonym as increased in no. of cells is considered as growth as well reproduction. Organisms like mule and liger can't reproduce fertile offspring.

- Bilateral and protostomial eucoelomate eumetazoa with metamerically segmented body and each segment bearing a pair of jointed locomotory appendages.

- “Arthopoda” literally means animals bearing jointed feet (Gr., arthron = jointed + podos = foot).

- These are extremely successful animals due to a protective exoskeleton and jointed appendages.

- That is why, more than 8 and half lac arthropod species are known as against about 2 and half lac species of the remaining animals.

1. Definition

A centrosome is an organelle found in cells that consists of two centrioles. A centriole is a structure found in a cell that is comprised of microtubules that are arranged in a particular way.

1. Size

A centrosome is of variable size but always bigger than a centriole. A centriole has dimensions that are approximately 500 nm long and 200 nm wide.

1. Formation

The pericentriolar material helps form the centrosome by organizing the centrioles. Proteins starting with SPD-2 recruit other proteins such as SAS-4, SAS-5, and SAS-6 to form the centriole.

1. Location

The centrosome occurs near the nucleus, and after it has copied itself, on opposite sides of the nucleus. The centriole can occur either near the nucleus or near the cell membrane.

1. Function

The function of the centrosome is to produce the spindle during mitosis and to help regulate intracellular transport. The function of the centriole is to form the centrosome and to form the basal body that gives rise to cilia and flagella