Introduction To Biology Class 9

B. Write short answers for the following questions.

 1. How the understanding of physics can help the biologist?

Ans. Physics provides the basis for biology. Without space, matter, energy and time components that make up the universe as living organisms would not exist. Since biology has its foundation in physics, it applies physical natural laws to the study of living organisms. For instance, physics helps explain how bats use sound waves to navigate in the dark and how wings give insects the ability to move through the air.

 

2. Which career would you like to adopt after studying biology and why?

Ans. I would like to adopt field of medicine and surgery. The field of medicines is related with the diagnosis and treatment of human diseases. In surgery, the defective parts of the body are repaired, replaced or removed. One can choose these professions in the same course (MBBS) after studying biology at higher secondary level. This field can help me to help the humanities.

3. Write the translation of any three verses of the Holy Quran related to the creation of mankind.

Ans.

 

1.       Who made all things good which he created, and He began the creation of man from clay. (Surah Al-Sajda Ayah:7)

2.       Verily We created man from a product of wet earth; (Surah Al-Mominoon Ayah: 12)

3.       He created man of clay like the potter's. (Surah Al-Rahman Ayah: 14)

4.Name few Muslim Scientists and their contributions in the field of biology and medicine. Muslim scientists and their contributions

Ans: Jabir Bin Hayyan (721 - 815 AD)

He was born in Iran and practiced medicine in Iraq. He introduced experimental chemistry. He also wrote a number of books on plants and animals. Among these, "Al-Nabatat" and "Al-Hayawan" are very famous He was also an astronomer, pharmacist, physician, philosopher and engineer. f. .Al-Farabi

Al Farabi:

This renowned Hakim and biologist lived in 870 - 950 AD. He wrote two books "Kitab-ul-Nabatat" which is about plants and "Kitab-ul-Haywanat" which is about animals.

Ali Bin Isa:

He was a well-known eye specialist. He worked on the structure, function and diseases of the eyes. He described 130 diseases of the eye in his book. The book was translated into many European languages.

Ibn-ul-Nafees:

He was a renowned biologist of 13th century A.D. He described the circulation of blood in human body.

5.What level of organization is represented by Volvox?

Ans. Volvox is a green alga. It is a common example of unicellular colonial organisms. It forms spherical colonies of up to 50,000 cells. They live in a variety of freshwater habitats

LONG QUESTIONS (Introduction To Biology Class 9)

1. How the understanding of biology can be improved through the knowledge of geography, chemistry and statistics? Give examples.

Ans. No doubt through knowledge of geography, chemistry and statistics the understanding of biology can be improved and it is evident from the following combined branches of study. Biochemistry is concerned with chemical substances and processes that occur in organisms. It involves the structural analysis of the organic compounds. These compounds make up those cells that play key roles in chemical reactions of life (e.g., photosynthesis and respiration reactions). Biogeography is the study of distribution of organisms in space and time. For example, in biogeography we study

i. Why polar bears are found only in certain parts of the arctic regions or ii. Why malaria-causing mosquitoes flourish in damp and warm areas.

Biostatistics or Biometry is the application of statistical and mathematical formulas in the study of biology. It involves the design, analysis and interpretation of research data. Biostatistics has made major contributions to our understanding of countless public health issues, such as: Chronic diseases. Suc as Cancer.

2. Define biology. How can you describe your own body under different branches of biology?

Ans. Biology is the science of life. The word "Biology" is derived from two Greek words "Bio" means 'life' and "Logos" means 'to study'. In 1736, a Swedish Scientist Carl Linnaeus forthe first time used the word biology. Biology has three major divisions:

a. Botany: It is the study of plants.

 b. Zoology: It is the study of animals.

c. Microbiology: It is the study of microorganisms e.g. viruses, bacteria and microscopic fungi.

Branches of Biology and our Body: i. Morphology is the study of form, shape and structure of organisms.

ii. Anatomy organisms. is the study of internal structures of

iii. Histology is the study of the composition, structure and functions of plant and animal tissues.

iv. Physiology deals with the functions of different parts of organisms and the activities occurring in them.

v. Embryology deals with embryo and the phenomena involved in the formation of embryo and its development into a new organism.

vi. Taxonomy is the study of classification of organisms and their scientific naming.

vii. Cell Biology or cytology is the study of cells and their organelles.

viii. Palaeontology is the study of fossils of past organisms. The study of fossils of plants is called

xi. Paleobotany and the study of fossils of animals is called Paleozoology.

viii. Immunology deals with the body's system of defense against disease-causing microorganisms. ix. Genetics deals with the study of transmission of characters from parents to off springs

X. Biotechnology is the study of the use of organisms for the benefit and welfare of humanity.

xi. Environmental biology is the branch of biology which deals with inter-relationship of organisms and their environment. processes by which an organism develops from a zygote to its full structure.

xii. Developmental Biology – the study of the processes by which an organism develops from zygote  to its full structure.

xiii. Cryobiology the study of the effects of low temperatures on living organisms.

3. Enlist the various levels of biological organization and explain it with an example.

Ans. Levels of Biological Organization: Level 1: Sub-atomic Particles and Atoms: You know that living and non-living matter is composed of simple units called atoms. Each atom is further composed of sub-atomic particles (electrons, protons and neutrons). The bodies of organisms are made of 16 kinds of elements. These elements are called bio-elements. Out of these bio-elements: Only six (O, C, H, N, Ca, and P) make 99% of the protoplasm. Other ten (K, S, Cl, Na, Mg, Fe, Cu, Mn, Zn, and I) collectively make 1% of the protoplasm.

Level 2: Molecules and Compounds:

 i. Atoms combine through bonds and form molecules and compounds.

ii. Similarly, the atoms of bio-elements combine to form bio-molecules.

iii. There are two types of bio-molecules.

iv. The bio-molecules with low molecular weight are called micro-molecules e.g. water, amino acids, glucose etc.

v. The bio-molecules with higher molecular weights called macro-molecules e.g. starch, protein, lipids etc.

Level 3: Organelles: i. Different bio-molecules combine together in a specific manner and form sub-cellular structures called organelles e.g. mitochondria, chloroplast, ribosome etc.

ii. Each organelle performs a particular function. Example: Mitochondria provide energy to the cell and ribosomes prepare proteins. Level

4: Cells: i. Cell is the basic structural and functional unit of an organism.

ii. It consists of many organelles such as, Golgi bodies, mitochondria, and lysosomes etc. which perform different

specific functions inside the cell. iii. In unicellular organisms, a single cell makes the whole body.

iv. While in multicellular organisms, there are more levels of biological organization.

 

Level 5: Tissues:

i. In multicellular organisms, the cells which are similar in structure and perform similar functions make groups. ii. Such groups of cells are called tissues. For example, in photosynthesis. secretions. plants mesophyll tissue is made of cells which perform iii. In animals, glandular tissue is made of cells which produce

Level 6: Organs:

Different tissues work together to perform a specific activity. Such a group of related tissues is called an organ. For example, the organ stomach is made of two major tissues. Its epithelial (glandular) tissue secretes gastric juice for the digestion of proteins while its muscular tissue contracts and grinds food.

Level 7: Organ Systems: The organs in turn coordinate and constitute an organ system which performs a particular function e.g. blood circulatory system in animals. The blood circulatory system is composed of organs like heart, arteries, veins and capillaries.

Level 8: Organism: i. Different organ systems then collectively form a whole organism.

ii. In case of man, different organ systems such as blood circulatory system, respiratory system, digestive system etc. work in coordination. iii. Similarly in plants, root and shoot systems constitute plant in body.

4. Explain the role of bio elements for living organisms. Ans. The Bio elements Or biogenic elements (bio = life, genes = beginning) are those chemical elements that make up the matter of living beings.

There are approximately 70 of these elements, which vary in different proportions and not all are present in all living beings Bio elements are the units which living things are composed of a. The atoms that make up all living things mostly consist of six different chemical elements: carbon (C), oxygen (O) hydrogen (H), nitrog en (N), phosphorus (P) and sulphur (S). b. These elements constitute more than 99% of the matter found in living things. They are called primary bio elements.

 

c. Oxygen is important for such significant biological processes as DNA synthesis, enzymes activation, cellular cycle regulation, gene transcription activation, and apoptosis. The review is also devoted for oxygen carriers in living organisms, e.g., hemoglobin, mioglobin and the toxicity of oxygen and ozone. Carbon atoms have the ability to link to other atoms. This allows life to take place and is why carbon is the most important bio element.

In living organisms, carbon and hydrogen make easy partners. Besides acting as an important structural element, hydrogen has a hand in nearly every single physiological function of living organisms due to

Biology

 usefulness and abundance. In the task of digestion, hydrogen bonds with chlorine to form hydrochloric acid, which breaks down fat and protein in the stomach. In the task of aerobic respiration, the movement of free-floating hydrogen atoms helps stimulate the production of energy; this is similar to the way in which a water pump can create energy potential that can do work. Next to carbon, there is probably no other element used quite so often and for so many important functions. g. Phosphorus is an essential mineral primarily used for growth and repair of body cells and tissues. Phosphorus is commonly found in the body as phosphate. Phosphates play an important role in energy production as components of ATP, or adenosine triphosphate.

h. Other chemical elements are found in living things; however, they appear in smaller quantities. Which are called as secondary bio elements. i. They are: calcium (Ca), sodium (Na), magnesium (Mg) and potassium (K). j. Lastly, trace elements are elements which are found in living things, but only in small amounts (0.1%). k. Although trace elements are not common, they are also important for certain functions. Examples of these are: iron (Fe) and iodine (I).

5. Who classify the living organisms into five kingdoms?

Explain each kingdom with the living organisms included in it. Ans. Robert Whittaker in 1968 classified all living organisms into five kingdoms. This is known as "Five-Kingdom System of Classification". These five kingdoms are:

1. Prokaryote 2. Protista 3. Fungi

Animalia

Kingdom Prokaryotae (Monera)

4. Plantae

ii. These organisms lack membrane bounded nucleus and other organelles inside their cells.

iii. Their cell wall is made up of murine.

Examples: Bacteria and Cyanobacteria.

Kingdom Protista or Protoctista

i. This kingdom included eukaryotic organisms which are usually small and having differences with the organisms of other eukaryotic kingdoms.

ii. They usually live in aquatic habitats.

Examples: Algae, slime molds, protozoans (Plasmodium, Amoeba and Paramecium) are some of the examples of this kingdom.

Kingdom Fungi

i. Fungi include organisms which are all eukaryotic and multicellular.

ii. Their cell wall is made of chitin. iii. They do not have chloroplast, so they cannot synthesize their own food and are therefore heterotrophic. iv. The food is stored inside the body in the form of glycogen. Examples: Some of the examples are Mushrooms, Molds, Puffballs, yeast etc.

Kingdom Plantae

i. This kingdom includes multicellular and eukaryotic

organisms which are autotrophic in nature.

ii. Their cell wall is made of cellulose and mostly lack centrioles inside their cells.

iii. The reserve food is in the form of starch.

Examples: Brassica, Mulberry, Ferns etc.

i. This kingdom includes multicellular and eukaryotic

Kingdom Animalia organisms which are heterotrophic in nature.

ii. These organisms lack the cell wall and centrioles are present in the cells.

iii. The reserve food is glycogen.

iv. The members of this kingdom can be split into two groups i.e vertebrates and invertebrates. Examples: Animals include jellyfish, worms, insects, fish, reptiles, birds, mammals etc.