The Living World

Species is the group of the organisms which are similar in morphologically, anatomically and reproductively also.

As we move from the species to the kingdom the related characters decreases and dissimilarity increases.

It is according to the standard rule of the classification.

TAXON -SUFFIX

Division - phyta

Order -ae

Class -ales

Family -aceae

Systematics is the study of diversity and all their comparative& evolutionary relationships based on comparative anatomy, physiology, ecology and biochemistry.

Group of related species which have more characters in common, compared to the species of other genera.

e.g. Panthera leo & Panthera tigris belongs to genera Panthera.

Both lion and tiger are having several common features, hence grouped under same genus.

In plants classes with few similar characters constitutes a division.

E.g. Dicots and Monocots together form division Angiospermeae.

Botanical garden and zoological parks are the ex-situ strategy of conservation, which are used to provide protection to both endemic and exotic species.

Zoological parks provide protection to the animals whereas Botanical garden is a strategy used to conserve plants species.

Taxonomic keys are the schemes for identification of plants and animals based on contrasting characters called the couplets, each character is called the lead.

Due to its analytical nature, a species can be identified hence it can be used to form taxonomic aids like Flora and Manuals.

All living organisms, whether of the present time, past or of future are linked to one another by sharing of the common genetic material, but to varying degrees.

Response to stimulus is the outcome of consciousness. Consciousness is the most obvious and technically most complicated defining property.

E.g.- photoperiod affects reproduction in seasonal breeders.

Plant shows response towards light.

Humans have self-consciousness.

This is according to the classification system proposed by ICBM.

Family: Tuberosum

Kingdom: Polymoniales

Order: Solarium

Species: Plantae

Genus: Solancaceae

Besides Linnaeus, George Bentham and Joseph Dalton Hooker are known botanists who gave the natural system of classification of flowering plants.

ICZN stands for International Code of Zoological Nomenclature. It acts as an adviser and arbiter for the zoological community. It also provides and regulates a uniform system of zoological nomenclature ensuring that every animal has a unique and universally accepted scientific name.

The taxonomic key provides a certain structure on the basis of which the user can sort out the taxonomic position of the unknown species. These keys are written in series of couplets. Couplet contains pair of contrasting characters which means two opposite description of an organism.

A monograph is a written account or description of a single thing or a group of things. So monographs would contain information about nay one taxon such as it may be about one genus or family at one time.

Amoeba is a unicellular organism. The terms growth and development maybe equally applicable for it since its reproduction is dependent on its growth. In multi-cellular organisms, mitosis is responsible for growth of cell numbers. In case of amoeba, because it is a single cell organism, its growth via mitosis is the same as reproduction since it divides to give rise to new individual.

Metabolism is defined as the sum total of all biochemical reactions taking place within any living organism in order to sustain and maintain life. During metabolism, the body converts the food source into energy which can then be utilised by the various organs and tissues and cells. Metabolism is a principle characteristic of living organisms.

Kew Royal Gardens in London is the world's largest botanical garden.

Some of the well known botanical gardens in India are:

1. Sanjay Gandhi Jaivik Udyan in Patna

2. Hyderabad Botanica Garden

3. NTR Garden, Hyderabad

4. Botanical Garden Sarangpur

5. Cubbon Park, Bangalore

When the iceball is rolled its size increases, it happens due to extrinsic growth by the deposition of the same material.

But in case of living beings intrinsic growth occurs. In unicellular living organisms reproduction takes place by splitting of parent cell into two daughter cells i.e. binary fission. Hence reproduction is equivalent to growth.

It can be concluded that growth in case of ice ball is completely different from the growth which occurs in case of living organisms.

It’s better to call it as biodiversity; biodiversity is a term which defines the sum total of organisms present in a specific area.

Whereas diversity is a broad term which may be used either foe living organisms or non living things. It operates for a very large area as well.

The hierarchy followed in plants:

Species → Genus → Family → Order → Class →Division → Kingdom

Suffixes used by botanists are as follows:

Taxon Suffix

a) Division -phyta

b) Class -ae

c) Order -ales

d) Family -aceae

These variants are called the ‘ecotypes’. Plants show changes in morphological features in response to the altitudinal gradient.

When plants are grown under similar environmental conditions, they faces same climatic condition, stresses etc. Hence shows similarity.

But when they are grown in separate geographical area, environment offers them different abiotic factors like light, temperature, availability of water, pH of soil, climate etc. Hence all these things bring out the variations in morphology which helps the plant to adapt well according to the environmental conditions.

For preparing a herbarium sheet, paper is cut in the desired length →say, 29 x 41 cm.)

Dried specimen is taken and mounted on the sheers with the help of glue. You may use cellotape if desired.

Labels are out underneath each specimen.

Collections tools will include:

1. Digger

2. Knife and Scissors

3. Newspaper

4. Blotting sheet

5. Plant press

6. Notebook

7. Magnifying glass

The information that will be provided:

1. Scientific name of specimen

2. Taxonomical details

3. Common name

4. Collector’s name

5. Place of collection

6. Date and Time

Eichhornia crassipes, commonly known as common water hyacinth, is an aquatic plant native to the Amazon basin. It is often problematic since it grows at a phenomenal speed and becomes a nuisance.

Rauvolfia serpentine is commonly known as the Indian snakeroot or devil pepper. It is native to the Indian subcontinent and has medicinal usage.

Different plants have different names that may be given by the local population or the name may be popular throughout the country. But often these local names aren’t common throughout the world. They are often known by different names in different parts of the world. To solve this problem, plants →and animals) are given scientific name. This scientific name is common throughout the world. For example: A mango is known as a mango in certain English speaking countries. However it is called Aam in Inida. But it has only one scientific name which is common throughout the world and it is Mangifera indica.

Two species differ from one another in terms of reproduction. What we mean by this is that they cannot interbreed i.e. they are reproductively isolated. They share the same genus but they remain different species.

All living phenomenon are possible because of underlying interactions. Similar to how properties of tissues aren’t present in the cells that make them up, cellular organelles are not present in the molecular constituents of the organelle but arise doe to interactions happening between the molecular components that make up the organelle.

These interactions result in properties at higher level of organisation. This phenomenon is the true hierarchy of organisational complexity at all levels.

The number and kinds of organisms is never constant. Populations are constantly affected by various factors. These factors include:

1. Season: Some organisms, plants and animals alike, are present in the ecosystem only during certain time. For example Mayfly, Mayflies spend a year awaiting their birth, and then most die after living just one day.

2. Extinction: Some species might be wiped out due to human or environmental activities.

3. Human activities: Deforestation causes a loss of a great number of organisms, hunting reduces the number of organisms.

The object which are self-regulating, evolving and self-replicating in nature are termed to be living.

It refers to organised state of molecules which are able to show growth, development, response to external stimuli.

The 4 defining characteristics are-

i) Growth

ii) Reproduction

iii) Metabolism

iv) Consciousness

i) Growth:

- It refers to an irreversible process of increase in size [either increase in mass, volume or in number of an individual].

- May be of 2 types:

a) Extrinsic growth –deposition of material on the outer surface.

b) Intrinsic growth – inside the body/cell.

Intrinsic growth occurs due to addition of material & formation of cells inside body – this is called intussusception.

However, in non-living things, similar materials get deposited on their outer surface. This is called accretion.

In unicellular organism increase in number of organism is equivalent to growth.

[Due to binary fission]� each member splits into 2.

ii) Reproduction:

- Biological process in which an organism give rise to individuals similar to themselves.

- Reproduction is of two types:

i) Asexual reproduction

• Uniparental

• With or without the involvement of gametes.

• Identical progeny’s produced

• E.g.- cell division

Budding

Regeneration

Fragmentation

Binary fission

Etc.

ii) Sexual reproduction

• Bi-Parental

• Involves formation & fusion of gametes.

• Brings out variation.

iii) Metabolism:

It is the sum total of all chemical & biological reactions occurring simultaneously inside the cells.

- It is of 2 types

i) Catabolism – involves break down of Biomolecules

ii) Anabolism – involves building up of Biomolecules.

It plays vital role in functioning of the living forms.

iv) Consciousness

• Ability of the body to sense & respond to the external stimuli.

• It can also be explained as self-awareness in humans.

• Plants can sense physical stimulus like light, water, temperature etc.

• Photoperiod affects reproduction in seasonal breeders.

With the help of taxonomic aids new identified species can be easily classified.

The scientist has to do comparative studies of the morphological & anatomical features with the features of existing plants present in the taxonomical aids.

And the according to binomial nomenclature given by Carl Linnaeus the species can be classified.

Some of the taxonomical aids that can be used are flora, manuals, monographs, catalogues etc.

→a) This is according to the rules of ICBN & ICZN that the scientific names specifically the genus & species epithet need to be written in italics.

→b) It refers to Linnaeus, Linnaeus was the first to discover this plant.

He identified & classified the plant hence to give him credit and honour Linnaeus is added as the suffix.

Collection of information, techniques, procedures which helps to identify & classify an individual are called taxonomic aids.

Importance of herbarium

a) Collection of dried, pressed & preserved plants in sheets is called herbarium.

b) These sheets are arranged in a systemic manner according to the accepted system of classification.

c) It is used to provide information about flora.

d) It is used to study the morphology of plants.

e) Hence its comparative studies are used in identification of unknown plants.

Importance of museums

It consists of collection of preserved plants & animal used for study & references.

Many museums publish journals, research papers to make available the results of research in their collection.

Taxon refers to any levels of grouping of organisms.

It may represent any rank in the classification.

Species � Genus � Family � Order � Class � Phylum/Division � Kingdom

Phylum in animals and division in plants.

As we go up in the hierarchy, the number of related characters decreases.

In the given reference, a ‘key’ is a taxonomical aid. A key is used to identify plants and animals based on their similarities and dissimilarities. The keys made are based on the contrasting characters that are depicted by the organisms, these are known as couplets.

A key represents the choice made between two given options opposite in nature. The comparison of the contrasting characters results in acceptance of one and the rejection of another. Keys are generally analytical in nature.

We all know that living beings are bio-chemical organisms. They are made up of chemicals. A number of metabolic activities are taking place inside of us at all times. Metabolism is defined as the sum total of all chemical reactions that take place inside the body. Metabolism is purely characteristic of living beings. No living organism can exhibit metabolism.

However, these reactions can be replicated outside a living body i.e. in a cell free system. But that doesn’t make them living. The reactions do not lead to generation of life or maintenance of life hence cannot be called living.

A coma is defined as a prolonged state of unconsciousness. When a person is in coma, they are unaware of their environment. Even though the person is alive and appears to be sleeping, their state is different from a sleeping person. The brain is functioning at its lowest stage of alertness. The person’s organs maybe linked to machines that might be helping them to live, for example a pace maker. It we consider consciousness as a characteristic of living beings then a person in coma might not be considered living. However, a lot many metabolic activities still take place and people often come out of their comatose state, so they are living.

Whole moong daal has an intact embryo whose respiration rate is slow during the phase of dormancy. When these are provided with growth condition, like providing it with water, growth is restored and the seed →moong daal) germinates and forms a new plant.

On the other hand, broken moong daal’s embryo isn’t intact. As a result of this it cannot respire and doesn’t grow or germinate.

By this comparison, we can classify whole moong daal as living and broken moong daal as non-living.

A living thing has multiple level of organisation. Each level of organisation has its own properties, which are not found in its constituents. Some of the example that can be stated here are:

1) Blood: Blood is a connective tissue. It is a fluid tissue consisting of RBCs, WBCs and platelets. These components individually have different properties but as a unit they make up the fluid tissue that is the blood which serves many purposes.