Unit 1 – Introduction To Biology (Exercise Questions)

Answers the following Questions
Q.1. Arrange these structures in order of lower level of organization t upper level and write the level against each structure. Neuron, nerve system, electron, man, mass of neurons, carbon, mitochondria, brain protein.
Q.2. How would you define biology and relate it with its major divisions.
Q.3. Describe different Branches of Biology
Q.4. Give points to advocate that Biology is liked with physics, chemistry, mathematics, geography and economics.
Q.5. How would you distinguish the biomolecule from other molecule? What is the criterion for classifying a biomolecule as micromolecule or macromolecule?
Q.6. Describe the levels of organization of life.
Q.7. Is there any division of labor among the cells of a colony? If you find division of labour among the cells and tissue what level of cellular organization is it?
Short Questions – Text Exercise
Q.1. Define biotechnology.
Q.2. What do you mean by horticulture and how is it related to agriculture?

THE TERMS TO KNOW

Q.1. Arrange these structures in order of lower level of organization t upper level and write the level against each structure. Neuron, nerve system, electron, man, mass of neurons, carbon, mitochondria, brain protein.
Answer:
Arrangement of structure in order of lower level of organization to upper level:

Q.2. How would you define biology and relate it with its major divisions.
Answer:
The Study of the structure and functions of living organism is very important to understand the nature of these organism. It also provides information for the remediation of human problems in the fields of food, health and environment explain and describe the world of the living organisms.
Definition of Biology:
Biology is the scientific study of living things in which all aspects of living organisms are discussed. Word biology has been derived from two Greek words:
“Bios” meaning Life and
“Logos” meaning Discussion, reasoning, discourse, thought. It means the study of life discussion on life.
Major Divisions of Biology:
There are three major divisions of biology with respect to three major groups of living organisms. These divisions deal with the study of different aspects of animals, plants and microorganisms. These include:-
Microbiology:
It is the study of microscopic organisms, such as viruses, bacteria, microscopic algae, some fungi and all protozoa.
Botany:
It deals with the scientific study of plants.
Zoology:
It deals with the scientific study of animals.
With the progress of science, large volume of information is being gathered under the major head of biology. So it has become compulsory to divide it into a number of branches. This brings the convenience to study all the major aspects of living organisms.

Q.3. Describe different Branches of Biology
Answer:

Q.4. Give points to advocate that Biology is liked with physics, chemistry, mathematics, geography and economics.
Answer:
In ancient times, the scientific information was not classified into different branches of science, as it exists today like biology, physics, chemistry and mathematics etc. AU the scientific information was therefore included
under one head “Science”, but with the passage of time, scientific information increased manifold and this enormous scientific knowledge was then classified into different branches. However, the interrelationship of these branches cannot be denied. Biology includes the information on different aspects of life and this information is related to the other branches of science as well. In fact every branch of science has relationships with other branches of science. This interrelationship provides the basis for interdisciplinary sciences of biology are:-

1. Biophysics
It deals with the study of principles and laws of physics, which are applicable to the biological phenomena; for example movement of muscles and bones follows the principles of physics.
2. Biochemistry
The study of different chemical compounds found in organism and the underlying chemical processes in living organisms is called biochemistry. For example the processes of phosynthesis and respiration can be well
studied with the help of the knowledge of chemistry.
3. Biogeography
It deals with the study of occurrence and distribution of different species of plants and animals in the different geographical regions of the world. It applies the knowledge of geography to determine the characteristics of
living organisms found in a particular region.
4. Bio-economics
It deals with the study of organism from economic point of view. It includes the study of the cost effectiveness and viability of biological projects from commercial viewpoint. For example the cost and profit of a crop of wheat can be calculated through bio-economics to determine the benefits or losses.
5. Biomathematics
The study of biological processes with the help of mathematical tools and techniques is called biomathematics. Mathematics has found both the theoretical and practical applications in the biological research. For instance, biologists have to apply the rules of mathematics to analyze the data collected after experimentation.

Q.5. How would you distinguish the biomolecule from other molecule? What is the criterion for classifying a biomolecule as micromolecule or macromolecule?
Answer:
Molecular Level
Molecule: In organisms elements usually do not occur in isolated forms. The atoms of different elements combine with each other through ionic or covalent bonding to produce compounds. This stable form is called a molecule. Hydrogen, carbon, oxygen, nitrogen, phosphorous and sulphur are the most common atoms found in biological molecules.
Except for hydrogen, each of these atoms lacks two or more electrons to fill its outer most electron shell and can share or transfer electrons with two or more other atoms.
Conjugated Molecules:
Two different macromolecules belonging to two different categories usually combine together to form larger biomolecules called conjugated molecules, such as glycoprotein (carbohydrates and proteins), lipproteins
and nucleoproteins etc.

Q.6. Describe the levels of organization of life.
Answer:
Level of Biological Organization:
Biological organization is not simple. It has high degrees of complexity because of which the living organisms are able to carry out a number of processes, which distinguish them from he non-living things.
We can summarize different levels as the subatomic particles make atoms and atoms join to make molecules. Different biomolecules then make organelles and organelles assemble together to make the simplest living unit i.e. the cell. The cells are then organized to form tissues and different relative tissues make an organ. The organs which perform related functions make organ system which in turn joins to make a complete individual. The individuals of the same species live together and make a population. The populations of different species which live in the same habitats constitute
1. Subatomic and Atomic Level:
ATOM: All living and nonliving matter are formed of simple units called atoms which literally mean something that cannot be cut (a = without, tom = cut).
ELEMENTS: The living substance is formed of a large number of elements. There are about 92 kinds of elementary found in nature. Each element is made up of a simple type of atoms.
The atoms are further made up of the subatomic particles. The most stable of these subatomic particles are protons electrons and neutrons. The numbers of there particles is definite in a specific atom.
Bioelements
16 elements out of 92 naturally occurring elements are called bioelements which take part in making the body mass of a living organism. Out of these 16 bioelements, only six (0, C, H, N.Ca and P) make 99% of the total mass
of a living organism while other ten (K, S, CI, Na, Mg, Fe, Cu, Mn, Zn and I) collectively make rest of 1 % of the Total mass.

2. Molecular Level.
Molecule: In organisms elements usually do not occur in isolated forms. The atoms of different elements combine with each other through ionic or covalent bonding to produce compounds. This stable form is called a molecule. Hydrogen, carbon, oxygen, nitrogen, phosphorous and sulphur are the most common atoms found in biological molecules. Except for hydrogen, each of these atoms lacks two or more electrons to fill its outer most electron shell and can share or transfer electrons with two or more other atoms.
Conjugated Molecules:
Two different macromolecules belonging to two different categories usually combine together to form larger biomolecules called conjugated molecules, such as glycoprotein (carbohydrates and proteins), lipproteins
and nucleoproteins etc.
3. Organelle and Cell Level.
A large number of biomolecules are associated in particular way and form organelles. The organelles are the sub cellular structures and after assembling together form cells.
Numerous sub cellular structures like mitochondria. Golgi complex, Endoplasmic reticulum, ribosome’s have been studied for their structure and function with the help of electron microscopy and staining techniques.
These organelles are specialized to perform specific functions. For example ribosomes are specialized for protein synthesis; mitochondria are specialized for respiration and chloroplasts for photosynthesis. In this way, functions of the cells are accomplished by these specialized organelles. This arrangement of the organelles is an example of division of labour within the cell.
The prokaryotic cells have limited number and types of organelles. Prokaryotes are made up of simple type of cells which lack membrane bound organelles, e.g.; mitochondria, golgi complex etc. Eukaryotes are made up of complex cells having membrane bound organelles. They have large number and types of organelles in their cells. A cell membrane is however present in all the cells i.e prokaryotic and eukaryotic. In some cases, such as bacteria and most of the protists, the entire organism consists of a single cell while in case of most fungi, some protists, animals and plants the organism consists of up to millions of cells.
5. Tissue Level.
In animals and plants, groups of similar cells are organized into loose sheets or bundles performing similar functions called a tissue. Each tissue has a particular function in the life of the organism. Each cell in a tissue
performs its own life processes but it also performs some specific processes related to the function of the tissue.
Plant Tissues:
In plants, the tissues are generally divided into two types:
(a) Meristematic tissue (un differentiated)
(b) Permanent tissue (differentiated tissue)
Meristematic tissues are made up of un-differentiable cells which have the ability to divide. These tissues are located at the tips of roots and shoots.
The permanent tissue is subdivided into three types:
(i) Epidermis tissues: Living tissues included epidermis and periderm.
(ii) Ground Fundamental tissue: The fundamental tissues are found in the interior of plant, which include parenchyma, collenchymas and sclerenchyma.
(iii) Vascular tissue: The vascular tissues of the plants are primarily xylem and phloem.
Animal Tissues:
In animals, tissues are of four major types:
1. Epithelia ————– a covering and glandular.
2. Connective ————- a connecting & supporting tissue.
3. Nerve ————— a conducting tissue.
4. Muscle ———— a contracting tissue.
Organ Level:
In higher organisms especially in animals, different types of tissues having related functions are organized together to form a functional unit called organ. Different tissues perform their specific functions and these
functions collectively become the function of that organ. Take an example of stomach which is an organ specialized for the digestion and storage of food. Two major types of tissues are organized to form the structure of s stomach. These include epithelial tissue that secretes the gastric juice for digestion and muscular tissue which brings about contraction of stomach walls for grinding of food, mixing of gastric juice with food and moving the food I
to posterior end. Both these tissues performs their own specific functions, which collectively become the function of stomach.
Organ System Level:
Organ system is the next level of organization in multicellular organisms. In an organ system, different organs performing the related functions are organized together. In an organ system each organ performs its specific function and the functions of all the organs appear as a single process formation of the organ system. For example, digestive system is an organ system which carries out the process of digestion of food. The major organs that make up this system included oral cavity esophagus, stomach, small intestine, large intestine, liver and pancreas All these organs perform some specific role in the process of digestion.
Functions of digestive organs and sum up processes of digestive system

The organ system is less developed in plants as compared to animals. The complexity of organ and organ system level in animals is related with for a greater range of functions and activities as compared to plants.
Individual (whole organism) Level:
Different organs and organ systems in plants and animals are organized together to form an individual. In an
individual, all the organs and organ are organized in such a way that all two functions processes and activities
are well coordinated. For example, when a human being is engaged in continuous and hard exercise, a number of processes start simultaneously in his body such as muscle contraction, increased rate of breathing, respiration and
heartbeat. These increased rates of breathing, respiration and heart beat supply more oxygen, food and energy to the muscle cells, which they need at that time for continuous work. In animals, this regulation of activities is called coordination, which is achieved through nervous system and hormones while in plants, this coordination is brought about only through hormones.

8. Population Level:
Biological organization does not stop here but it extends up to the population level where the biologists study the interactions among members of the same species living in the same habitat. A population is defined as a group of organisms of the same species present in the same place at the same time. For example. number of rats in a field of wheat in 2009. number of students in biology class in 2008. Similarly. human population is the number of human beings in (1 particular city or a country in a particular year or month.
At this level of biological organization. biologists study life in some new parameters. which cannot be studied at individual level. For example. gene frequency, gene flow. age distribution. population pressure and population
density.
9. Community Level:
The assemblage of different populations interacting with each other written a same environment constitutes a community, For example. a forest can be considered as a community. It has different plants species such as oak. trees ash tress bushes and grasses etc: different animal species and different species of microorganisms (bacteria and fungi).
Community is actually a collection of organisms of different species. in which one population may decrease and other may increase, This change in population size usually occurred due to fluctuations in a biotic factors and
changes in the size of other species. Some communities are quite large and complex such as a forest community or a pond community. While other communities are comparatively simple such as a fallen log with different populations under it. In a simple community, the number and size of populations is limited. Therefore. any change in the biotic or a biotic factors may have drastic and long last effects in a community.
10. Biosphere level
Biosphere is the part of the Earth inhibited by organisms. All ecosystems are constituted living and non living components which interact with each other. It is also called the zone of life on earth.

Q.7. Is there any division of labor among the cells of a colony? If you find division of labour among the cells and tissue what level of cellular organization is it?
Answer:
Yes there is division of labour among the cell of colony. Such type of division found in multicellular organization.
Explanation:
tissue can be defined as a group of cells which perform the similar function and our morphologically model is similar. in multicellular non primitive organism the cells are divided into various types so as to perform the labour much easily.
Hence there is tissue and organ level of Organization in such organism. there is also morphological changes in each of the tissue and cell so that the work is performed more efficiently.
Short Questions – Text Exercise

Q.1. Define biotechnology.
Answer:
It deal with the practical application of organisms and the biological processes for the welfare of mankind e.g. disinfection and preservation of food, preparation of insulin and biogas from bacteria.


Q.2. What do you mean by horticulture and how is it related to agriculture?
Answer:
Horticulture
Horticulture deals with the art of gardening. The horticulture. The horticulture work for the improvement of existing varieties and for the production of new varieties of ornamental and fruit plants.

THE TERMS TO KNOW