Characteristics of life - class-XI

The living organisms are composed of cells. The cells divide and the body of the organisms show growth due to the increase in the number of cells. The trees are the living organisms and show the process of growth. Road, pen and water are non-living organisms which do not show the process of growth. 

Stimuli can be of any type whether physical or mechanical, biological as in response to another organic thing or chemical including chemical compounds or environment.

Microbial conversion of organic matter to methane called Biogas has become attractive as a method of waste treatment and resource recovery. This process is anaerobic(absence of oxygen) and is carried out by action of various groups of anaerobic bacteria.
Three basic points about this process are that most of the important bacteria involved in biogas production process are anaerobes and slow growing, a greater degree of metabolic specialization is observed in these anaerobic microorganisms and that most of the free energy present in the substrate is found in the terminal product methane. Since less energy is available for the growth of organism, less microbial biomass is produced and, consequently, disposal of sludge after the digestion may not be a major problem.
Hence, the statement is false.

The living organisms are composed of cells which forms the structural and functional unit of the life forms. Some of the animals are composed of only one cell which forms the complete body are known as unicellular. Some of the animals are composed of many cells which form tissues and organs are known as multicellular. 

Flower, horse and seed are made up of cells and are capable of growth and development. Table lack the property of growth and development. Therefore, table is a nonliving thing.

Under adequate and favourable conditions, the lifespan of a

• Fruit fly is 40-50 days.
• Crocodile is nearly 70-100 years, depending on the species.
• Parrot is from 50-95 years, depending on the species.
• Banyan tree is 200 years.
• Crow is 7-22 years, depending on the species.
• Butterfly is from weeks to months, depending on the species.
• Tortoise is 150 years.

• Metabolism is sum total of all the reactions taking place in the cell. 
  
• It involves the synthesis and degradation of various biomolecules for many functions like energy conservation, energy release, homeostasis etc.
  
• Metabolism can Be divided into two categories: Catabolism - the breakdown of molecules to obtain energy and anabolism - the synthesis of all compounds needed by the body.
  

A- 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.

Planet Mars is believed to contain three most essential requirement of life i.e., Chemical building blocks abundance , source of water and a source of energy as volcanoes . Thus, it is expected that apart from earth Mars is the planet which can cater life.

The high boiling point of water is advantageous to living organisms because organisms can absorb a great deal of heat before they reach the boiling point from organisms and population. Thus the organisms will not be affected by the high temperature because water can absorb the heat and maintain its homogeneity by uniformly dissipating it.

• Organic compounds are macromolecules or compounds associated with life processes such as carbohydrates, proteins, lipids, nucleic acids.
  
• The main constituents of this organic compond are Carbon, hydrogen, oxygen and phosphorous.
• In carbohydrates, the main components are carbon, hydrogen and oxygen atoms.
• Eg- Glucose- is a single-unit carbohydrate or monosaccharide with six carbon atoms, 12 hydrogen atoms, and six oxygen atoms.
• In proteins,  the main components are carbon, hydrogen, oxygen, and nitrogen atoms.
• Eg- Any amino acid has a basic amino group (−NH2), an acidic carboxyl group (−COOH), and an organic R group (or side chain).
• Nucleic acids contains carbon atoms, phosphate and nitrogenous base.

The most important characteristic defining an organism as living is the presence of protoplasm in it's cells. While the other three options which are multiplication, movement and growth can not define living to the full extent. As plants are immobile yet they are living. The external growth of mountains, boulders, and sand is observed. Mules, sterile worker bees and sterile couples can not multiply but they are living organisms.

Metabolism is the sum of all chemical reactions occurring within a living organism and is considered a defining characteristic of life, as it is present in all living organisms.

1. Metabolism occurs 'unexceptionally in all living organisms' and this is a defining feature of living beings. 
   
2. Reproduction is absent in sterile or infertile living beings.
3. Organisms like the majority of sponges and plants do not move, but they're still living.
4. Patients in a coma do not interact with the environment, yet all the metabolic processes occur thus they are living.
   

Life span : The period from birth to the natural death of an organism. Life span can never be correlate with the size of animals. Life span of some animals are given below ;

Living things are lively and active and exhibit characteristics of life, like growth, movement, reproduction, response to stimuli (like touch, smell, light) . These activities are done by the cells of which the living things are made up of. Some examples of living things around us are human beings, animals, plants and microorganisms.

Consciousness refers to individual awareness of thoughts, memories, feelings, sensations, surrounding and environment and responding to external and internal stimuli

• Non-living things increase in size due to the addition of similar materials to their outer surface, they include crystals, glaciers, stones and mountains

Living organisms must maintain a constant internal environment while living in a constantly changing external environment. Maintaining the internal environment is important because the processes that keep the cell alive can only take place under certain conditions. There are different processes that occur in the body to maintain the constant internal environment such as diffusion, osmosis, homeostasis, active transport, passive transport, endocytosis, exocytosis, etc. Homeostasis helps to maintain an equilibrium of an internal environment. 

All living things and dead are made up of the cells which perform life processes for maintaining life. They give the response to the stimulus or environmental factors. But growth is the characteristic of both living and dead as dead like wood shows growth by the absorption of water. Thus, the growth is the characteristics of living things but not the defining or fundamental properties of living things. Hence, the correct answer is option D.

• Non-living things do not grow through internal metabolic functions but by adding on from the outside. Non-living things do not need the energy to continue to exist. Some nonliving things such as crystals grow by accumulating more of the same material of which they are made.
• Living things exhibit growth, movement, reproduction, respiration and metabolism. Living things use energy, respond to stimuli and adapt to their environment.
• So, the correct answer is 'Growth occurs from outside'.

Non-living beings are made up of a single or combination of molecules repeated in a sequence or randomly arranged. A molecule is a group of two or more atoms bound by chemical bonds. A few examples of non- living being is water, table, ground.

The bacteria is a unicellular living organism which has been included in the group of prokaryotes. The earthworm is an example of segmented worm which belongs to the phylum Annelida. These are the living organisms which can perform the different biological processes like respiration, digestion, reproduction, etc. The plant roots cannot perform the functions without the other parts of the plants like leaves which produce food. 

Electron is a stable sub-atomic particle with a charge of negative electricity, found in all atoms and acting as the primary carrier of electricity in solids. 

The crystals are the non-living forms which show an external form of growth. The atoms form the nuclei and then the other molecules in the solution when cooled come together forming an aggregated structure. The new atoms and molecules are added from the outside and so, the growth in the non-living forms is always external. There are no cells which divide and show internal growth as in the living forms. 

The genetic material in the living organisms has the ability to replicate and form more copies during the process of cellular division. This property of replication is shown by all the living organisms. The viruses are the non-living obligate parasites. They cannot perform any life functions like replication, respiration, digestion, reproduction, etc. 

Both living things and non living things are made up of molecules which are composed of atoms. This atoms follow same laws of physiochemistry. 

(A)Carp - (2) 20 Years -Carps are various species of oily freshwater fish from the family Cyprinidae, a very large group of fish native to Europe and Asia. For example, Cyprinus carpio (common carp) The life span of carp is about 20 Years.

A. 5 years life span – Octopus

B. 10 years life span –  Rose

C. 15 years life span – Crow

D. 20 years life span – Dog

So, the correct option is ‘dog’,

The original scientific names were taken from Latin and Greek languages. New names are now derived either from Latin language or are latinised. This is because Latin language is dead and therefore, it will not change in form or spellings with the passage of time.

(i) Increase in mass and increase in number of individuals are twin characteristics of growth is true
(ii) Metabolic reactions can be demonstrated outside the body in isolated cell-free systems is true
(iii) 'Response to stimuli' is a defining property of living organisms is true

All organisms share common genetic material, i.e., DNA and RNA. However, it can vary to certain degrees.

Response to stimuli also known as sensitivity is shown by all the living organisms whether it is unicellular or multicellular. This is essential for one-celled organisms for their survival. For example, if a unicellular organism is exposed to a chemical, it will react either by producing another chemical or by moving away from the stimulus to survive. 

Habitat is associated with the geographical area one lives in.

Respiration and excretion are two exclusive properties of living being ,whereas locomotion can be seen in non living organism owing to certain factors liike wind, water etc.
So, the correct option is B. ( Respiration and excertion )

A sequence of biochemical reactions occur in the living organisms is called Metabolism. it is the life-sustaining process occurs in the living organism and always takes place in the living organism. Metabolism can be demonstrated out side the living body. They do not occur in the non living body.

So, the correct option is 'ABC'.

• The loss of trees, which anchor the soil with their roots, causes widespread erosion throughout the tropics.
• Vacuoles are storage bubbles found in cells. They are found in both animal and plant cells but are much larger in plant cells. Vacuoles might store food or any variety of nutrients a cell might need to survive. They can even store waste products so the rest of the cell is protected from contamination.
• Maize is a wind-pollinating crop and is able to cross-pollinate in neighboring fields.
• In legumes and a few other plants, the bacteria live in small growths on the roots called nodules. Within these nodules, nitrogen fixation is done by the bacteria, and the NH3 they produce is absorbed by the plant. Nitrogen fixation by legumes is a partnership between a bacterium and a plant.

The components of the cell and the arrangement of the individual parts within the cell form the cellular organisation. There are five stages which include cell, tissue, organs, organ systems and organisms. The cellular organisation provides the complete about the working model of the cell and its components.