What is living? Questions in English

(A) Aristotle $(384-322 \, B.C.)$ is known as the '$Father\, of\, Zoology$'.
He is also considered the 'Founder of Taxonomy' because he was the first to classify the animal kingdom into two distinct groups based on the presence or absence of red blood: $Enaima$ (vertebrates with red blood) and $Anaima$ (invertebrates without red blood).
Therefore,the correct option is $A$.

(C) . Autotrophy is a characteristic feature of plants. Plants are capable of synthesizing their own food using sunlight,water,and carbon dioxide through the process of photosynthesis,whereas animals are heterotrophic and depend on other organisms for their nutrition.

(B) According to the biological species concept,a species is defined as a group of individuals that can interbreed among themselves to produce fertile offspring.
Members of the same species share a common gene pool and are reproductively isolated from other such groups.
Therefore,the most fundamental characteristic that defines a species is the ability to interbreed.

(A) The biological species concept,proposed by Ernst Mayr,defines a species based on the ability of individuals to interbreed and produce fertile offspring.
While interbreeding is the most accurate and useful criterion for defining a species,it is generally not used in practice for identification because it is difficult to observe in nature,especially for extinct species,asexual organisms,or organisms that are geographically isolated.
Therefore,taxonomists often rely on morphological characteristics for routine identification.

(D) $Amoeba$ exhibits irritability,which is the ability to respond to external stimuli. When an $Amoeba$ is touched with a needle,it perceives the needle as a mechanical stimulus or a potential threat. Consequently,it retracts its pseudopodia and moves away from the point of contact to protect itself.

(B) Heterotrophs are organisms that cannot synthesize their own food from inorganic sources.
They depend on other organisms or organic matter for their nutrition.
Therefore,they require an environment that provides pre-existing organic compounds (such as carbohydrates,proteins,or fats) to serve as a source of carbon and energy.
Autotrophs,on the other hand,can utilize inorganic sources like nitrates or ammonium salts to synthesize their own organic molecules.

(A) Bioluminescence is a phenomenon where living organisms produce and emit light.
In this process,the chemical energy stored within the organism is converted into light energy through an oxidation reaction involving a substrate (luciferin) and an enzyme (luciferase).
Therefore,the correct conversion is from chemical energy to light energy.

(C) Irritability (or sensitivity) is the property of living organisms,specifically the protoplasm,to respond to stimuli or changes in the external and internal environment.
$1$. Reproducibility refers to the ability to produce offspring.
$2$. Mutability refers to the ability to undergo genetic changes or mutations.
$3$. Adaptability refers to the ability to adjust to new environmental conditions over a period of time.
Therefore,the correct property associated with responding to environmental changes is Irritability.

(D) The fundamental biological difference between living and non-living entities is the presence of protoplasm.
Protoplasm is often referred to as the 'physical basis of life' because it is the living content of the cell,containing all the organelles and biochemical machinery necessary for metabolism,reproduction,and homeostasis.
While non-living things may exhibit growth (e.g.,crystal accretion),movement,or changes in size,they lack the complex,self-sustaining,and organized protoplasmic structure that defines life.

(C) The genetic code (triplet code) is universal,meaning it is common to all living organisms.
Energy storage via high-energy phosphate bonds (like $ATP$) is a fundamental mechanism in all life forms.
Ribosomes are universally present as the site of protein synthesis in all cells.
However,the specific types of proteins present in the body vary significantly between different species and even between individuals,as they are determined by the specific genetic makeup and evolutionary history of the organism. Therefore,this is not a common characteristic.

(A) The maintenance of a constant steady state within the internal environment of the body is an inherent characteristic of living organisms. This process is known as $Homeostasis$.

(C) Life as we know it requires liquid water to function as a universal solvent for biochemical reactions. The moon lacks an atmosphere and liquid water on its surface,which are essential prerequisites for the existence and sustenance of biological organisms.

(A) mule is the offspring of a male donkey (ass) and a female horse.
According to the biological species concept,a species is defined as a group of organisms that can interbreed to produce fertile offspring.
Mules are sterile and cannot reproduce among themselves to maintain a population.
Therefore,a mule does not meet the criteria to be classified as a distinct biological species.
Thus,the correct statement is that a mule is not a species.

(B) At the molecular and analytical level,life is understood as a complex system of matter and energy interactions. Biological processes,such as metabolism,growth,and reproduction,are fundamentally driven by the exchange and transformation of energy within biological molecules. Therefore,the most accurate scientific description of life at this level is the interaction between matter and energy.

(D) Option $D$ is incorrect because genes are the fundamental units of heredity and are directly responsible for the stability (through faithful replication) and changeability (through mutations and recombination) of species over generations.
Option $A$ is correct as life processes are the result of complex biochemical reactions within an organism.
Option $B$ is correct as organisms consist of both organic molecules (like proteins,lipids,carbohydrates) and inorganic compounds (like water and minerals).
Option $C$ is correct as it reflects the principle of biogenesis,which states that life arises from pre-existing life.

(A) The biological concept of species,proposed by Ernst Mayr,defines a species as a group of interbreeding natural populations that are reproductively isolated from other such groups.
Therefore,the core of this concept is reproductive isolation,which prevents gene flow between different species and maintains the genetic integrity of a species by preventing hybridization.

(B) The complexity of body organization is primarily determined by the number of cells an organism possesses. Organisms are classified as $Unicellular$ (consisting of a single cell) or $Multicellular$ (consisting of many cells organized into tissues,organs,and organ systems). This classification reflects the structural and functional complexity of the organism's body.

(D) The functions and characteristics of plants are determined by a combination of factors.
$1$. Habitat: The environment where a plant grows dictates its survival strategies.
$2$. Adaptations: Morphological and physiological changes allow plants to thrive in specific conditions.
$3$. Interrelationships: Interactions with other organisms (like pollinators or symbionts) influence plant traits.
Therefore,all these factors contribute to explaining the characteristics and functions of plants.

(C) The science that deals with the study of plants from various perspectives is known as $Botany$.
$Zoology$ is the study of animals.
$Botanical$ $Garden$ is a place where plants are grown for scientific and educational purposes.
$Microbiology$ is the study of microscopic organisms.

(D) In biology,the characteristics of living organisms,including plants,are defined by processes such as growth,reproduction,metabolism,response to stimuli,and the completion of a life cycle.
Death is a natural biological end point for all living organisms.
'Greatness' (or 'Mahatta' in the context of the provided options) is a subjective or abstract concept and does not represent a biological function or a physiological characteristic of plants.

(A) The term 'living organism' is the general and common name used to describe any individual entity that exhibits the characteristics of life,such as metabolism,growth,reproduction,and response to stimuli. While 'Protista','Metazoa',and 'Metaphyta' are specific biological groups or kingdoms,'living organism' is the overarching term for all living forms.

(D) The term $Biology$ is derived from two Greek words: $Bios$ meaning $life$ and $Logos$ meaning $study$. Therefore,$Biology$ is defined as the branch of science that deals with the study of living organisms and their vital processes.

(B) According to the biological species concept,a species is defined as a group of organisms that can interbreed under natural conditions to produce viable and fertile offspring.
In plants,this means that two individuals belong to the same species if they can freely interbreed and produce fertile seeds that can grow into new plants.
While chromosome number,genetic similarity,and morphological appearance are important,the fundamental criterion for defining a species is the ability to interbreed successfully.

(C) Nomenclature is the process of providing a distinct and universally accepted name to a living organism based on specific principles and criteria established by biologists.
$1$. Identification: The process of determining the correct group or taxon to which an organism belongs.
$2$. Classification: The process of grouping organisms into categories based on their similarities and differences.
$3$. Nomenclature: The system of naming organisms.
$4$. Systematics: The study of the diversity of organisms and their comparative and evolutionary relationships.
Therefore,the correct answer is Nomenclature.

(C) Individuals of the same species are defined by their ability to interbreed under natural conditions to produce fertile offspring. This process of interbreeding allows for the exchange of genetic material within the population,which is a fundamental criterion for species classification in biological terms.

(D) The correct answer is $D$. Genes are the fundamental units of heredity and are directly responsible for both the stability (inheritance of traits) and the variations (mutations or recombination) observed within a species. Therefore,the statement that genes are not responsible for the stability or variation of a species is incorrect.

(A) The biological species concept,proposed by Ernst Mayr,defines a species as a group of organisms that can interbreed under natural conditions to produce fertile offspring.
In the context of plants,if two individuals can freely interbreed and produce viable seeds (which can further grow into fertile plants),they are considered to belong to the same species.
While genetic similarity,morphological appearance,and chromosome numbers are important,the ability to interbreed is the definitive criterion for biological species classification.

(B) Life requires specific conditions to exist,including the presence of an atmosphere,liquid water,and a suitable temperature range. The Moon lacks an atmosphere,which means it lacks essential gases like $O_2$ (oxygen) and $H_2O$ (water vapor). Among the given options,the absence of water is the most critical factor for the lack of life on the Moon,as water is the universal solvent and essential for all known biological processes.

(C) Paleontology is the branch of biology and geology that deals with the study of fossils of plants and animals to understand the history of life on Earth.
$A$. Ecology is the study of organisms and their environment.
$B$. Ethology is the study of animal behavior.
$D$. Ornithology is the study of birds.

(C) The biological species concept defines a species as a group of organisms that can interbreed under natural conditions to produce fertile offspring.
Therefore,the defining characteristic of organisms belonging to the same species is their ability to interbreed $(C)$.

(B) The biological species concept defines a species as a group of organisms that can interbreed under natural conditions to produce fertile offspring.
Therefore,the ability to freely interbreed and produce fertile offspring is the fundamental criterion for determining if two organisms belong to the same species.
While chromosome number and genetic similarity are important,they do not guarantee reproductive compatibility,which is the defining characteristic of a species.

(A) The $\text{Å}$ is a unit of length equal to $10^{-10} \text{ meters}$.
Since $1 \text{ meter} = 100 \text{ cm}$ $(10^2 \text{ cm})$,
$1 \text{ Å} = 10^{-10} \times 10^2 \text{ cm} = 10^{-8} \text{ cm}$.
Therefore, the correct option is $A$.

(D) The correct answer is $D$. Cells receive instructions for division from hereditary material,which is $DNA$ (Deoxyribonucleic acid),not proteins. Proteins are the products of gene expression,while $DNA$ carries the genetic information required for cellular processes and replication.

(A) Consciousness is considered the defining property of all living organisms.
Every living organism,whether prokaryotic or eukaryotic,unicellular or multicellular,has the ability to sense their environment and respond to environmental stimuli.
While reproduction and growth are characteristics of living beings,they are not defining properties because some living organisms (like sterile worker bees or infertile human couples) do not reproduce.
Locomotion is not a universal feature of all living organisms (e.g.,plants).
Therefore,consciousness is the only property that is exhibited by all living organisms.

(B) The process by which organisms maintain a relatively constant internal environment,such as body temperature or osmotic balance,despite fluctuations in the external environment is called $Homeostasis$. This mechanism allows organisms to function optimally regardless of external conditions.

(D) Living organisms exhibit a unique level of organization known as biological or cellular organization. While non-living matter also consists of atoms and molecules,the specific arrangement of these components into complex,self-regulating,and self-replicating structures (like cells and organelles) is exclusive to living beings. Therefore,the hierarchical organization starting from the cellular level is a defining characteristic of life.

(A) The scientific study of life in outer space or the search for life beyond Earth is called $Exobiology$.
$Cryobiology$ is the study of the effects of low temperatures on living organisms.
$Euphenics$ is the study of biological improvement of human beings by altering their environment.

(B) Homeostasis is defined as the ability of an organism or a cell to maintain internal equilibrium by adjusting its physiological processes.
It involves the tendency to resist changes in the internal environment,ensuring that conditions like temperature,$pH$,and solute concentration remain within a stable range despite external fluctuations.

(C) The scientific method is a systematic process used to investigate phenomena.
$1$. It involves the formulation of hypotheses based on observations.
$2$. Every hypothesis must be testable through experimentation.
$3$. $A$ critical component of the scientific method is the use of a control experiment to compare results and ensure validity.
$4$. Observations,whether direct or indirect,are the foundation of the method.
Therefore,the statement that 'no control experiment is designed' is incorrect.

(A) Respiration is a fundamental metabolic process that occurs in all living organisms to release energy from food molecules.
While growth,germination,and photosynthesis are important biological processes,they are not universal to all living organisms.
For example,photosynthesis occurs only in autotrophs,and germination is specific to seeds.
Respiration,however,is essential for the survival of all living cells.

(C) The fundamental property of all living organisms is the ability to reproduce or divide. Cell division is a vital process for all living organisms,as it allows for growth,development,and the replacement of damaged cells. Without cell division,life could not be sustained or propagated.

(D) The functions and characteristics of plants are determined by a combination of factors.
$1$. Cellular structure: It defines the basic biological processes and metabolic activities of the plant.
$2$. Habitat: It influences the physiological and morphological traits required for survival in a specific environment.
$3$. Adaptation: It represents the evolutionary changes that allow plants to function optimally in their surroundings.
Therefore,all these aspects collectively clarify the functions and characteristics of plants.

(D) Botany is the branch of biology that deals with the scientific study of plants. It encompasses a wide range of scientific disciplines including:
$1$. The study of plant structure (morphology and anatomy).
$2$. The study of plant evolution and their phylogenetic relationships (how different plant groups are related).
$3$. The study of plant physiology,ecology,and classification.
Therefore,all the mentioned aspects are integral parts of the study of botany.

(D) Plants are living organisms that exhibit various biological processes to survive and propagate.
$1$. Nutrition: Plants are autotrophic,synthesizing their own food through photosynthesis,which is a fundamental characteristic.
$2$. Interrelationships: Plants interact with their environment and other organisms (e.g.,symbiotic relationships,ecological roles),which defines their functional niche.
$3$. Reproduction: Plants undergo various modes of reproduction (sexual and asexual) to ensure the continuity of their species.
Since all these aspects are essential for defining the life,functions,and characteristics of plants,the correct answer is $D$.

(D) The term $Biology$ is derived from two Greek words: $Bios$ meaning 'life' and $Logos$ meaning 'study'.
Therefore,$Biology$ is defined as the science that deals with the study of living organisms and their vital processes.
Option $D$ correctly describes this definition.

(B) Living organisms exhibit specific characteristics that distinguish them from non-living matter. These include growth,reproduction,ability to sense the environment (consciousness),metabolism,cellular organization,and self-replication. These functional attributes define the state of being 'alive'. Therefore,the characteristics related to the functions performed by an organism are the basis for distinguishing living from non-living entities.

(B) Defining an $Organism$ is not easy because there is no single,universally accepted definition that covers all living entities,including viruses,which exist at the boundary of living and non-living. While $Growth$,$Reproduction$,and $Development$ are characteristics of living organisms,the term $Organism$ itself encompasses a vast diversity of life forms,making a precise,all-encompassing definition difficult.

(D) To identify a living organism,biologists primarily focus on its $Morphology$ (external form and structure). $Morphology$ provides the initial basis for classification and identification of organisms in biological studies.

(D) Metabolism is a defining feature of all living organisms. It refers to the sum total of all chemical reactions occurring in a living body. While reproduction,growth,and response to the environment are important,metabolism is considered a fundamental characteristic because no non-living object exhibits metabolism. Therefore,it is a defining feature of life.