Education Is The Key To Success: Biology For Class IX - Chapter No.1 - Introduction To Biology

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CHAPTER 1
INTRODUCTION TO BIOLOGY

Questions and Answers

Q.1: What is life?
Ans: Life cannot be defined properly, but on the basis of life processes, it can be identified through following functions of living organisms.

Digestion
Respiration
Metabolism
Movement
Growth
Development
Excretion
Irritability
Reproduction

Q.2: Define Biology?
Ans: Biology:
The word biology comes from Greek language “Bios” meaning “life” and “Logos” meaning “thought or reasoning”. Thus biology meaning study of life.

"Biology is a branch of natural sciences which deals with the study of living beings. It provides the knowledge about living organisms which differ from each other in shape, size, composition etc."

Q.3: Name and define main divisions of biology?
Ans:MAIN DIVISIONS OF BIOLOGY
There are three major divisions of biology:

Zoology:
The word Zoology is derived from Greek language, “Zoon” meaning animals and Logos meaning “study or knowledge”. It deals with the study of animals.
Botany:
The word Botany is taken from Greek language, “Butane” meaning plants and Logus meaning “study or knowledge”. It deals with the study of plants.
Microbiology:
It deals with the study of microscopic organisms such as Bacteria etc, which can be seen only with the help of microscope.

Q.4: Define branches of biology?
Ans: BRANCHES OF BIOLOGY:
Modern biology deals with the structure, function and many other descriptions of living things. Advance research during the 20th Century has led to the division of biology into specialized branches. Some important branches are defined below:

Morphology (Gr. morph; form, logos; discourse):
The study of external form and structure of organisms.
Anatomy (Gr. ana; part/up, tome; cutting):
The study of internal parts of body of living organisms by cutting them open.
Cell biology (L. cells, compartment, Gk. Bios= life; logos; discourse):
The study of cell and its organelle.
Histology (Gr. histos: tissue; logos, discourse):
The study of structure of tissues of plant and animals.
Physiology (Gr. physis; nature, logos, discourse):
The study about functions of living organisms.
Taxonomy (Gr. taxis, arrangement, nomos: name):
The study of the rules, principles, grouping and naming the living organisms.
Genetics (Gr. genesis; descent, origin):
The study of heredity, that is transferring of characters from parents to offspring.
Developmental biology (Gr. embryon; embryo, logos, discourse):
The study of formation and development of embryo.
Environmental biology:
The study of relationship between living organisms and non-living factors of environment and their effects on each other.
Paleontology (Gr. palaios; ancient, ontos; being, logos: discourse):
The study of remote past organic life, with the help of fossils.
Biotechnology:
The study about techniques for manipulation of gene to bring the changes in structure and location of genes to achieve desirable characters is called biotechnology.
Socio-biology (L. sociare; to associate,):
The study of social behavior of living organisms. i.e interaction between themselves.
Parasitology (Gr. para; up):
The study of parasites.
Pharmacology (Gr. pharmakon, drug;):
The study about action of drugs.
Molecular biology:
The study of organic molecules which constitute cell and its organelles.

Q.5: Describe the relationships of biology to other sciences?
Ans: Relationship Of Biology To Other Sciences:
Biology is a multidimensional subject and linked with other sciences. For example, the movement of animals follows the laws of motion in physics. Biology is considered as interdisciplinary science, which is related with other sciences. Some of these are mentioned below:

Biophysics:
It is a branch of physics, in which laws and techniques of physics are applied to explain the processes of life.
Example:
* The radio-physics branch where radioactive isotopes are used to trace the translocation of different materials within the organisms.
* Radio-labeling and carbon-dating also show some uses of radioactive isotopes in determining the age of fossils.
* Uses of sound waves as ultrasound and laser technology show relation of physics with biology.
Biomathematics / Biometry:
The branch of mathematics which collects data of living organisms using mathematical techniques and tools is called Biometry or Biomathematics.
Example:
It plays very important role in research.
Biochemistry:
It is branch of biology which deals with the study of molecules which form living organisms or cell and requires authentic knowledge about biology and chemistry to explain the synthesis of biomolecules and function of different molecules in the body of an organism.
Example:
The study of basic metabolism of photosynthesis and respiration involves the knowledge of chemistry.
Biogeography:
It deals with the distribution of different living organisms in different geographical regions of the world.
Example:
Many living organisms are restricted to particular geographical regions due to environmental conditions.
Bio-economics:
This deals with the economically important organisms involved in production.
Example:
Meat production, etc. are calculated for cost value and profit value.

Q.6: What professions or fields can biology students adopt as their career? Or Write a note on Career in biology? Or Describe the careers That the students, Who have chosen biology, can plan to adopt?
Ans: Careers in biology:
The career of student is subject to obtain a degree. The students, who have chosen the biology, they can plan to adopt some as a career in following fields:

Medicine and Surgery:
Medicine deals with diagnosis and treatment of diseases and surgery deals with repair, replacement or removal the affected organ.
Agriculture:
This deals with production of varieties of crops, fruit, vegetables, dairy products, etc. Pakistan being an agricultural country, it can play very important role.
Horticulture:
This is also part of agriculture, in which work is carried out for the development of new varieties of plants and their products.
Forestry:
Forests are the source of biodiversity of plants and animals of many kinds which live there. It is important in development of new forests as well as preservation of existing ones.
Farming:
In this profession, the development of different kinds of farms takes place, such as fish farm, cattle farm, poultry farm, etc. New technologies are used for the production of animals as source of meat and milk, leather, wool, etc.
Animal husbandry:
This profession is part of agriculture science. It deals with the care and breeding of animals which are beneficial for man.
Fisheries:
This profession deals with the increased quantity and quality of fish production. Fish is one of the best source of protein.
Biotechnology:
This is very important and sensitive profession. It deals with manipulation of gene to produce valuable chemical products, such as insulin, growth hormones, interferon, etc from bacteria as well as others.

Q.7: Write down the Quranic verses to explain about the origin of life and about growth and development of plant? OR
Write down the Quranic verse about the following:
(i) The Significance Of Water For Plants And Animals
(ii) Facts About The Growth And Variety Of Plants
Ans: QURANIC VERSES ABOUT THE ORIGIN OF LIFE:
The Almighty Allah has conveyed a great knowledge about the origin and characteristics of animals and plants through our Holy Book, the Quran. A few of Ayah are quoted as under:

The Holy Quran Has Explained The Significance Of Water For Plants And Animals At Several Places:
Allay Says;

“We made every living thing from water”.
(Surah: Ambia, Verse: 30)

“And Allah has created every animal from water of them there are some that creep on their bellies, some that walk on two legs; and some that walk on four. Allah creates what He will Lo! Allah is able to do all things.”
(Surah Al-Nur, Ayah-45)

Here water is symbolized with the protoplasm as the basis of life and the vital power of protoplasm seems to depend on the constant presence of water.

QURANIC VERSES ABOUT THE PLANT"S GROWTH AND DEVELOPMENT:
The Glorious Holy Quran Has Also Revealed Some Facts About The Growth And Variety Of Plants:

“And in the earth are neighboring tracks, vineyards and ploughed lands, and date-palms, like and unlike which are watered with one water. And we have made some of them to excel others in fruit. Lo! Here in verily are portents for people who have sense.”
(Surah: Al-Ra'd, Ayah: 4)

Here Allah has revealed some facts about plant growth and development.

Q.8: Describe the role of Muslim scientists in the field of biology.
Ans: Contribution of Muslim Scientists:
The Muslim scientists have played great role in the development of biological science. They began experiments and observations from the first Century of Hijra. Following are some details about the important Muslim scientists, who made significant contribution towards the development of biology.

1. Jabir Bin Hayan:

Period: He was born 722 and died in 817 A.D.
Birth Place: He was born in Iran
Contribution: He worked in the field of chemistry.
Famous Books: He also wrote a number of books on plants and animals. Like:
(i) “Al-Nabatiat” on plants.
(ii) “Al Haywan” on animals.

2. Abdul Malik Asmai:

Period: He was born 741 and died in 828 A.D.
Contribution: He was great zoologist.
Famous Books: He wrote many books on animals. Like:
(i) “Al Kheil” on horse.
(ii)“Al-Ibil” on camels.
(iii)“Al-Shat” on sheep.
(iv) “Al-Wahoosh” on wild animals and
(v)“Khalqul Insan” on the different parts of human body and their functions.

3. Bu Ali Sina :

Period: He was born 980 and died in 1037 A.D.
Founder of Medicine: He was greatest of all the Muslim scientists and considered as the founder of medicine. He is called as Avicenna in the west.
Contribution: He identified many diseases like tuberculosis, meningitis and other such inflammations.
He also worked in the field of mathematics, astronomy, physics, paleontology and music.
Famous Books: He wrote books like:
(i) “Al-Qanoon” and
(ii) “Fil Tib Al-Shafa”.

Q.9: Describe the level of organization. Or Illustrate level of organisation?
Ans: Level Of Organization
The levels of organization in living world are based on chemical foundation. All the living organisms are made up of cells and the protoplasm of cell is the physical as well as chemical basis of life. These levels are as follows:

1. Atomic level of organization:

All the matter is made up of elements, which is composed of atom (a: not, tom: cut).
Each atom is made up of sub-atomic particles, such as electrons, protons and neutrons.
In nature, there are more than 100 kinds of elements and among these 16 elements are called as bio-elements, which are vital for life.
Only six elements such as C, H, O, N, S and P are called basic elements of life.

2. Molecular level of organization:

Molecules are formed by the binding of atoms.
These organic molecules of cells are called as bio-molecules.
These are constructed in great variety and complexity.
They are classified as micro-molecules and macro molecules.
Glucose, amino acid and fatty acids are micro-molecules.
Carbohydrates, proteins and lipids are macro-molecules.
The units of micro-molecules combine together to form macro-molecules.

3. Cellular level of organization:

The bio-molecules when work together in the form of suspension, It is called Protoplasm.
Protoplasm is the combination of organic and specific inorganic substances.
When protoplasm work in the form of a unit, this is called Cell.
Cell is the basic unit of living organisms.
When similar type of cells organize together in a group, called tissues.
The different types of tissues arranged in a particular manner to work together are called Organs.
Organs of different types work in a co-ordinated manner to perform a function are called Organ-system.
When different organ-system function in co-ordination in as a unit, they form a body or Multicellular Organism.

4. Taxonomic level:

Taxonomic level is another level of organization which is related with living organisms.
The Species is the smallest unit of taxonomic level of organization, which includes morphologically similar living organisms which inter-breed and produce fertile offspring.

5. Population level:

All the members of a species, living in specific habitat are called Population.
For example, A group of parrots living on tree, is called parrot population.

6. Community level:

The members of different species living in specific habitat are called as Community.
For example, A group of different kind of birds, living on tree, is called as bird community.

7. Ecological system:

Communities always depends upon their non-living environment in a reciprocal interaction for their survival.
For example, oxygen for respiration is obtained from environment and in turn given out CO₂ .
This interaction of living organisms with each other and with non-living of the environment is called Ecosystem or Ecological system.

8. Biosphere level:

The part of earth where life exists is called biosphere.
It consists of different kinds of Eco-systems.

Graphical Representation Of Level Of Organisations:

Q.10: What do you mean by Unicellular organizations and Colonial Organization?
Ans: Unicellular Organizations:
Definition: All the microscopic organism which can not be seen by naked eyes and consist of single cell are called Unicellular (uni = one cellular = cell) organism.

All single cell organisms carry out all activities of life.
They digest the food, respire, excrete, move etc on the cellular base by simple methods.
Unicellular organism also respond to their environments, get rids of waste, grow and reproduce.
Unicellular organisms include both prokaryotes and some eukaryotes.
Examples: Bacteria, Amoeba, Paramecium and Euglena are common examples of unicellular organisms.

Colonial Organization:
Definition: Many unicellular organisms live together by forming colonies but do not have any division of labor among them. Such Organisms are called Colonial organism.

In colonial type of cellular organization, each unicellular organism lives its own life.
They are not dependent on each other and never form any multicellular structure.
Example: Volvox is a green alga is an example of colonial form of organization.

Q.11: Describe the characteristics of Amoeba and draw a well labeled diagram also?
Ans: Amoeba:
Amoeba is a unicellular, microscopic and aquatic Eukaryote organism.
Habitat:
Amoeba is found in the mud of shallow pond, pools and at any stagnant water.
Size:
Its size is about 0.25 mm.
Shape:
Amoeba has an irregular shape i.e., no permanent shape and keep on changing.
Structure:
Amoeba is very simple in structure. It is made up of protoplasm. The protoplasm is surrounded by a membrane called cell membrane which helps in movement of molecules and protects cytoplasm. Protoplasm consist of two parts.

Cytoplasm
Nucleus

1. Cytoplasm:

Cytoplasm is differentiated into two portion.
Ectoplasm: The outer part of cytoplasm is clear (non granular) and transparent, called ectoplasm (gel) and
Endoplasm: The inner part of cytoplasm which is viscous, granular and translucent is called endoplasm (sol).
The cytoplasm contains following organelles:
Contractile vacuole: It removes excess water from bodty.
Food vacuoles: It contains food particles.
Mitochondria: It is a power house of the cell.
Pseudopodia (Psuedo = false, podia = a feet): Amoeba captures food particles with the help of psuedopodia. Psuedopodia also help in locomotion.

2. Nucleus:
It is usually present in the center but as Amoeba moves,the nucleus changes its position. Nucleus controls all the activities of a cell.

Respiration:
Amoeba respires by exchanging gases with the surrounding water through its surface.

Q.12: Describe the characteristics of Volvox and draw a well labelled diagram also?
Ans: Characteristics Of Volvox:
Volvox is a polyphyletic (many ancestors) genus of chlorophyte green algae in the family Volvocaceae. It forms spherical colonies of upto 50,000 cells.
Habitat:

They live in a variety of fresh water habitats and were first reported by Antonie Van Leeuwen Hoek in 1700.
Volvox once called algae that live together in a colony.

Volvox are not harmful to humans because they do not produce any toxic substance.

Structure:

Volvox is a unicellular organism. The cell has a nucleus, vacuoles and an eyespot.
Each cell performs all the metabolic functions independently such as respiration, photosynthesis, excretion, etc.
Movement: Each Volvox cell has two flagella. The flagella beat together to roll the body in water.

Nutrition:
Volvox cells have chlorophyll and make their own food by photosynthesis. These photosynthesis organisms are an important part of many aquatic ecosystem.

Q.13: Define multicellular Organization?
Ans: Multicellular Organization:
The organism formed by many cells is called as multicellular organism. Frog and mustard plant are examples of multicellular organization.

Q.14: Describe characteristics of Mustard plant? Also draw a well labeled diagram of Mustard plant?
Ans:Characteristics Of Mustard plant (Brassica):
Brassica campestris is commonly known as mustard plant and locally it is called “Sarsoon”.
It is multicellular and cultivated in winter season.
Size:
The length of this plant is 1 to 1.5 meter.
Structure:
This plant consists of following two parts:

The vegetative part: which consists of root, stem and leaves.
Reproductive part: which consists of flowers. Each flower is yellowish in color and produce seed.

Economical Importance:

The leaves of this plant are used as vegetable.
Seeds are used for oil extraction.

Q.15: Describe characteristics of frog? Also draw a well labeled diagram of Frog?
Ans: Morphology of Frog:

Rana tigrina is the scientific name of spotted frog found commonly in our region.
It is multicellular animal.
It belongs to class Amphibians because it lives in both water as well as on land.
Frog lives near ditches, pools, ponds, stagnant stream and slow moving rivers.
Its body is divided into head, trunk and limbs. There is no neck and no tail.
Bulging eyes are present on the conical head on either side.
Each fore limb has four fingers while there are five fingers in hind limbs.
Tympanic membrane in the form of circular area is present just behind each eye and help in hearing.
External nostrils are present at the tip of mouth for breathing.
Frog swims in water with the help of foot- web present in between the fingers of hind limbs.
Its body is made of well developed organ system with different organs. For example, digestive system, circulatory system, respiratory system, excretory system, reproductive system and nervous system.
All organs are made of different tissues such as epithelial, glandular, muscular, nervous etc.
It feeds on small insects.
Its skin is moist and glandular which make it slippery.
Frog lays egg in water during rainy season.
Frog hibernate during winter by burying themselves in the mud and live there throughout the winter. This phenomenon is called "Winter-sleep" or "Hibernation".

Q.16: Describe the procedure of dissection of frog and draw a well labelled diagram of dissected frog? OR Identify organs and organ systems in dissected frog?
Ans: IDENTIFICATION OF ORGANS AND ORGAN SYSTEMS OF DISSECTED FROG:
Material Required:

Preserved frog
dissecting tray
dissection box
pins

Procedure:

Place the preserved frog on a dissecting tray on its back, as all vertebrates are dissected ventrally.
Pin down the fore limbs and hind limbs.
Take scissor to cut the abdomen ventrally, from cloaca to the mouth.
Again cut down the skin of limbs from each side and pin down.
Expose the visceral organs clearly to observe organs.

Q.17: Draw a table to show different organs with relative organ system? And draw well labelled diagram of each system?
Ans: Different Organs With Relative Organ Systems:

Organ System	Organs
Digestive system	Alimentary Canal: Mouth, buccal cavity, Pharynx, Esophagus, stomach, small intestine (Duodenum, Ileum) , large intestine, cloaca, cloacal aperture. Glands: liver with gall bladder and pancreas.
Circulatory system	Heart, left and right atria, left and right ventricles, truncus arteriosus, Aortae, Vena cavae
Respiratory system	i. Buccal: Lining of mouth ii. Cutaneos: Moist Skin iii. Pulmonary: Lungs,nostrils, laryngo-tracheal chamber, bronchi, Alveoli
Excretory system	Kidneys, Ureter, Urinary Bladder, Cloacal aperture
Reproductive system	Fat bodies Male: Testes, vasa efferentia, urinogenital dust Female: Ovaries, Oviduct, Ovisac
Nervous system	Brain, Spinal Cord, Nerves