Intoduction to Biology- Class 9th Biology Notes

Intoduction to Biology- Class 9th Biology Notes

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CHAPTER NO# 01

INTRODUCTION TO BIOLOGY

Q#1:  What is Biology? 

The Scientific study of living organisms is called Biology.

The scientific study of living things in which all aspects of living things are discussed. The word biology has been derived from two Greek words:
i) Bios means Life  ii) Logos means discussion, thought, knowledge & study etc.


Q#2: What are the branches of biology with respect to various large groups? 

Biology has three main branches:
Microbiology: It is the scientific study of microorganisms e.g. Virus, Bacteria etc.
Botany: It is the scientific study of all plants.
Zoology: It is the scientific  study of all animals including man.


Q#3:  Define the branches of Biology? 
• Morphology: It is the study of shape, form and structure of an organism.
• Anatomy: The study of internal structure of living organisms is called anatomy.
•  Histology: It is study of tissues with microscope.  The study of tissues of plants and animals is called Histology.
• Cell Biology: It is the scientific study of cells and their organelles. It is the study of structure and function of cells. It is also known as cytology.
• Physiology: It is the study of the functions performed in different parts of organism.
• Ecology: It is the study of relationship between organism and their environment. It is also called environmental biology.
• Embryology: It deals with the study of the formation, development, structure and functional activities of embryos. It is study of all changes from zygote to organisms is born or hatched.
• Taxonomy: It is the study of classification and naming of living things.
• Genetics: It is the study of genes and transfer of characters from parents to offspring. Genetics is the study of heredity and variation.

• Paleontology: It is the study of fossils. It has two types:
(a) Palaeo-botany is the study of fossils of plants. (b) Palaeo-zoology is the study of fossils of animals. Fossils: Fossils are the dead remains of organisms preserved in rocks.
• Social Biology: It deals with social behavior of animals that make societies.
• Parasitology: It is the scientific study of parasites. Parasites are organisms that take food and shelters from living hosts and in return harm them.
• Biotechnology: It is the study of practical application of organism for the welfare of mankind. It is the latest profession. In this profession biologists produce useful products using micro-organisms.
• Immunology: It deals with the study of immunity system of the living organisms. Immunity system is a system which defence the body against invading microbes.
• Entomology: The term is derived from two Greek words: “Entomon” means “notched or segmented” and logos means “study, knowledge, discussion or thought”.
• Pharmacology: It deals with the scientific study of drugs.

Q#4:  Describe relationship of Biology with other sciences?                                                     
Biophysics: It deals with study of those laws of physics which are applicable on biological
phenomena.
Biochemistry: It is the study of chemicals found in living things. It is the study of chemical reactions taking place in living things.
Biometry or Biostatistics: The data collected from experiments and observations made on organisms, is analyzed by various methods of statistics. This is called biometry.
Biogeography: It is the study of distribution of different species of living things found in different
geographical region.
Bio-economics: It deals with the study of organism from economic point of view.


Q#5:  What are various careers in Biology?                                                                                            

Medicine/Surgery: This profession deals with diagnosis of diseases and their treatments. For this profession MBBS is basic course and then students go for specializations.

Fisheries: It is professional study of fish production.

Agriculture: This profession deals with the study of crops and animals, which are source of food.

Animal Husbandry: It is the branch of agriculture. It is concerned with care and breeding of domestic animals (livestock).

Horticulture: It deals with the art of gardening. A horticulturist works for betterment of existing varieties of ornamental plants as well as discover new varieties. It is also related to
Agriculture.

Farming: It deals with development and maintenance of different types of farms.

Forestry: These professionals look after natural forests and advise the government to plant new forests.


Q #6  :  Write a note on contributions of Muslim Scientists in the field of Biology?
Contributions of Muslims Scientists in the Field of Biology
Many Muslim scientists contributed a lot in the field of biology but the following names are more respectable:
a.  Jabir-Bin-Hayan
Period: 722-817 A.D
Books: Al-nabatat and Al-haywan
Contribution: He studied the life of plants and animals and wrote many books about them.


b. Abdul-Malik-Asmai
Period:741 A.D
Books: Al-Kheil, Al-Ibil, As-Sha, Al-Wahoosh, Khalaqul Insan.
Contributions: He described the body structure and functions of horses, camels, sheep, wild animals and human beings in detail.

c. Abu-Usman-Umer Al-Jahiz
Books: Al-Haywan
Contribution: He explained the characteristics of about 350 species of animals. He described the life of aunts. He wrote a famous book “Al-Haywan”. In this book he described his own observations on animals.

d. ABUL QASIM ALi – ZAHRAVI (936 – 1004 AD)
He was renowned surgeon of the Islamic world. He was famous for the removal of stone from the urinary bladder.

e. Al-Farabi (872-950)
 Books: Kitab ul-Nabatat,  Kitab ul-Haywanat
Contribution: He was also a scientist, cosmologist, mathematician and music scholar.

f. Ibn-ul-Haitham
Period: 965-1039 A.D
Books: Al-Manazir, Mizan-ul-Hikma
Contributions: Both of these books were famous and well known at that time. These books were translated into Latin, Hebrew, Greek and other western languages. He explained the structure and functions of eyes and suggested the cornea as a site of vision.

g. Bu-Ali Sina
He was born in Kharmsheen near Bukhara in 10th century AD. He was considered to be one of the founders of medicine.
Period: 980 A.D
Book: Al-Qanoon Fil Tib, Al-Shifa
Contribution: He wrote about plants, animals and non-living things in one book. Aside from medicine he was expert in mathematics, astronomy, physics, paleontology and music.

h.  Ibn-ul-Nafees (1213-1288)
Contribution: he described the blood circulation in the human body.

i. Ali Ibn-e- Isa
Contribution:
 He was a well-known eye specialist of his times and worked on structure, function and diseases of eye. He wrote three volumes on this subjects in which he has described 130 diseases of the eye.


Q#7:  What are the different levels of organization?

a)  Subatomic and Atomic Level:
All type of matter is made up of elements and elements are made up of atoms. The atoms are actually made up of many subatomic particles.
b) Molecular Level: 

In organisms, bio-elements do not occur in isolated form. They combine through ionic or covalent bonding. The stable particle formed by such bonding is called biomolecule. An organism is formed by large number of bio-molecules.

c) Organelles and Cell Level:
Bio-molecules join in a particular way and form organelles. Each type of organelle performs special function. Organelles form the cell which is unit of life. Some organisms consist of only one cell and called unicellular.
 d) Tissue Level:
In multicellular organisms, similar cells join into groups and called tissues.
e) Organ and Organ System Level: 
Same kinds of tissues are joined to form Organs. Each organ performs their special functions in living organisms.
For example: Legs are used to move. Eyes are used to watch etc. Many organs of similar
function are joined to form Organ system. For example in Digestive system, mouth, stomach
and intestine are involved.
f) Individual Level:
Different organs and organ systems are organized together to form an individual organism.
g) Population Level:
In population level, biologists study the relationship between different
members of same species living in the same habitat. A species is defined as a group of
organisms which can reproduce further. Habitat mean living area of an organism.
h) Community Level: 
Assemblance of different populations results into a community. For
example in a Forest populations of Lion, Monkeys, zebras and lions etc.
i) Biosphere Level:
 The part of earth inhabited by organism’s communities is known as
biosphere. It constitutes all ecosystems.

Q#8:  Write the major groups of organisms?                                                         
Ans: The major groups of organisms are prokaryotes, protists, fungi, plants and animals.

Q#9:  What is colonial type of cellular organization?
Ans: Many unicellular organisms live together and form colony, but do not have any division of labour among them. For example Volvox is green alga found in water.

Q #10:  What are the scientific name of Mustard plant and Frog?
Ans: Scientific name of mustard plant is “Brassica compestris” and of frog is “Rana  tigrina”.

THE END_-_-_-_-_-_ 

Chapter 2 notes biology-class 9th

Chapter 2  notes biology-class 9th

Give an example of solving biological problem keeping in view the study of malaria.

 Introduction: 

Malaria is a disease of chills and fevers with recurring attacks. Scientists observed that this disease was common in low, marshy areas.

The word “Malaria” was derived from two Latin words: i) Mala means bad. ii) Aria means air. 

So, the meaning of malaria becomes bad air. Quinine from cinchona bark was an effective remedy for malaria.

Observations: 

i) In 1878, a French army physician Laveran began to search for the cause of malaria.
ii) He observed the blood of malarial patients under microscope and found some tiny creatures in it.
iii) His discovery was not believed by other biologists.
iv) Two year later same results were drawn by another physician and three years later same observations were found third time.
v) The organism was given the name Plasmodium.

Hypothesis: 

Regarding malaria the hypothesis made was: “Plasmodium is the cause of malaria”

Deduction:

 Regarding malaria deduction was made from above hypothesis is: “If plasmodium is the cause of malaria, then all person ill with malaria should have plasmodium in their blood.”
Experiments:
• Then blood of 100 malarial patients was examined under microscope.
 • The results showed that all malarial patients had plasmodium in their blood. While 7 out of 100 healthy persons also had plasmodium in their blood.
• In the healthy people plasmodium was in incubation period (The period between the entry of parasite in host and the appearance of symptoms.)
• The result was convincing and proved the hypothesis.

 How Plasmodium enter in Man:

 Now next step was that how plasmodium gets into the blood of man? In this regard biologists were having following observations:
i) Malaria is associated with marshes
ii)  Drinking water of marshes does not cause malaria.

In this regard, A.F.A King made his observations in 1883. His observations were: 

i) People who slept outdoors in open spaces suffered more from malaria than www.allonlinefree.com those who slept indoors.
ii) People who slept under mosquito nets did not suffer from malaria. iii) Person who slept near smoky fire also did not suffer from malaria.
On the basis of these observations King suggested a hypothesis:
“Mosquitoes transmit Plasmodium and so are involved in the spread of malaria.” For this hypothesis, following deductions were made:
i) “Plasmodium should be present in mosquitoes”
ii) “A mosquito can get Plasmodium by biting a malarial patient”

Experiment of Ronald Ross: 

To test these deductions Ronald Ross, a British army physician performed his experiments in 1880’s in India.
• He allowed a female Anopheles mosquito to bite a malarial patient. He killed the mosquito some days later and found Plasmodium multiplying in mosquito’s stomach.
• Next step was to allow the infected mosquito to bite a healthy person. But this was a risky work as that healthy person can be suffered from malaria. So he selected sparrows for his experiment.
• He allowed a female Culex mosquito to bite a malarial sparrow.
• Then he allowed those mosquitoes to bite a healthy sparrow.
• The healthy sparrow also suffered from malaria.
• In this way he proves that plasmodium is the real cause of malaria and they are transmitted by mosquitoes.
In 1898, an Italian biologists performed same experiments on human beings and find the same results. This confirmed that mosquitoes are involved in the spread of this disease.

Theory:

 When a hypothesis has been proved by consistent results it becomes a theory.

Scientific Principle or Law: 

When a theory can explain many natural phenomena and consistently supported by experiments, and also universally accepted by scientists it becomes a scientific principal or Law.