Showing posts with label Biology. Show all posts
Showing posts with label Biology. Show all posts

12/24/2018

General Knowledge Notes For All Competitive Exams - Biology-Part -03

12/24/2018 0
General Knowledge Notes For All Competitive Exams - Biology-Part -03

NATURAL RESOURCES: USE AND CONSERVATION 

Resource : Any natural or artificial substance, energy or organism, which is used by human
being for its welfare is called a resource. Two types of resources are -
(a) Natural resources
(b) Artificial resources.

Classification Of Natural resources : Natural resources are classified into -
 (i) Inexhaustible resources may be renewable such as air, water (in oceans), solar energy etc.
(ii) Exhaustible resources may be non-renewable such as metals fossil fuels,soil, forest, fresh water, minerals, fossil fuels, etc.  
Soil is the uppermost layer of earth’s crust, which supports growth of plants.It is both a renewable and non-renewable resource.

Conservation: It is the sum total of activities, which can derive benefits from natural resources but at the same time prevent excessive use leading to destruction or neglect. Water is the most important component of all life forms. It regulates climate, generates electricity and is also useful in agriculture and industries. With increase in population and industrial growth, water is degraded day by day. Conservation and management of water are essential for the survival of mankind, plants and animals

Biodiversity : The variety of all plants, animals and microbes of a region is termed biodiversity.
Biodiversity is essential for maintenance of ecosystem. Though biodiversity is important for our survival, it is under threat due to the various human activities. So we should protect biodiversity by strategies like,
(i) In situ conservation
(ii) Ex situ conservation.

Endangered Species : The endangered species are those, which have been reduced in number to a
critical level and facing a high risk of extinction in the near future.The plants, animals and microorganisms other than the cultivated plants and domesticated animals constitute wildlife. Wildlife forms an important resource for maintaining ecological balance. Conserve it by establishing biosphere reserves, national parks and sanctuaries etc.

Sustainable Development : It is the development that meets the needs of the present generation and conserves it for the future generation.

Main categories of energy sources:There are two main categories of energy sources. They are-
(i) Conventional Sources of Energy: Conventional sources of energy may be
      (a) Conventional Non-Renewable Energy (Mostly fossil fuels found under the ground like coal,                oil and natural gas etc.)
       (b) Conventional Renewable Energy (firewood, cattle dung, charcoal etc.)

(ii) non-conventional sources of energy: The non-conventional energy includes solar energy, hydel energy, wind energy, nuclear energy, hydrogen energy, geothermal energy, biogas energy, tidal energy, Bio-fuel, etc.

Why to conserve energy? 
The demand for energy and exploitation of the energy sources is increasing dayby-day. Energy sources are depleting fast. There is an urgent need to conserve energy else adequate energy will not be available in future.

12/23/2018

General Knowledge Notes For All Competitive Exams - Biology-Part -02

12/23/2018 0
General Knowledge Notes For All Competitive Exams - Biology-Part -02
Earth is the only planet to support life. Earth provides soil, water and air to support it. Environment is defined as the physical, chemical and biotic conditions that surround and influence on living organisms.
Abiotic components: Abiotic components of environment are temperature, light, humidity, precipitation, wind minerals and the composition of air.The three physical components of earth are atmosphere, lithosphere and hydrosphere.

Biotic components: It  include plants, animals and microorganisms.

Ecology: Ecology is defined as the study of relationship between organisms and their environment. Ecology deals with various form of interaction between the organisms and their environment.

Genes:The levels of organisation in the living system starting from genes to community.

Ecosystem: It is defined as functionally independent unit of nature where living organisms interact among themselves as well as with their physical environment.Terrestrial and aquatic ecosystems are the two categories of natural ecosystems. Croplands and aquarium are the examples of artificial ecosystem.These biotic components of ecosystem interact with each other to give a physical character. These represent structural features of an ecosystem to an ecosystem.The important structural features of an ecosystem may be represented by its species composition, stratification, food relationship (trophic level food chain and food web).The structural components interact in a unit and produce certain functional aspects of an ecosystem such as productivity, energy flow and nutrient cycle etc. Humans occupy both primary and secondary levels of consumers.
Food Chain: Transfer of food from the plants (producers) through a series of organisms with repeated eating and being eaten is called food chain.

Food Web: A network of a connected food chains interrelated form a food web.

Flow of Energy: The process of transfer of energy through various trophic levels of the food chain is known as flow of energy.The quantity of energy flowing through the successive trophic level decreases. This is because a part of the energy is lost as heat and a part of energy used by the organism for its metabolism. Only 10% of the energy that enters the trophic level is transferred to the next trophic level. This is known 10% law. The flow of energy in an ecosystem is always linear. The number of trophic level in a food chain is limited in number (4 or 5).

Ecological Pyramid:The graphical representation of standing crop expressed as number biomass or energy is called pyramid of number. Pyramid of biomass and pyramid of energy respectively. These are collectively known as ecological pyramid.

Biome: A biome is a large ecosystem which is embracing the large landscape. Each biome is characterised by a specific flora and fauna.

Nutrient Cycle: The cycling of the nutrients in the biosphere is called biogeochemical or nutrient cycle. Carbon cycle and water cycle are two such example. Photosynthesis, respiration, decomposition and combustion are the important processes in carbon cycle. Evaporation, condensation and precipitation are the important processes in water cycle.


General Knowledge Notes For All Competitive Exams - Biology-Part -01

12/23/2018 0
General Knowledge Notes For All Competitive Exams - Biology-Part -01
General Knowledge Notes For All Competitive Exams - Biology-Part -01(Download as PDF)

Applications Of Genetic Engineering


At home we prepare food items such as yoghurt (curd), cake, bread, idli and dosa by the action of microorganisms, such as the bacteria and fungi. Brewers use yeast (fungus) to make beer. Antibiotics such as penicillin are obtained from certain fungi. Nowadays, biological processes such as fermentation by microorganisms is being used in industry on a commercial scale for making food, drinks, drugs (medicines) and industrial chemicals. Modern techniques in biotechnology are programming microorganisms for this task.

Protein manufacture :
We are well familiar that bacteria and yeasts have been used for centuries to produce cheese, and alcohol, and more recently antibiotics. Currently, plasmids in bioengineered bacteria carry some human genes and these genes are expressed to give large quantities of human proteins which are clinically useful. The development of recombinant DNA technology and gene cloning has generated
a new industry for manufacturing proteins. Earlier valuable proteins could be obtained from eukaryotes in small amounts and at heavy expense, but now these can be produced in large quantities. 
For example: Until sometime back, growth hormone was available only in tiny amounts and was extremely expensive as it had to be extracted from endocrine glands of certain animals. Today, it can be made available in large quantities through recombinant DNA technology. 
In 1982 production of human insulin became the first commercial success of recombinant DNA technology. There are several proteins of therapeutic (medical) value which are available now through recombinant DNA technology. These are cloned human gene products approved for use or being developed. 
Here lets know the names of proteins and their uses:
  •  Insulin - Diabetes mellitus
  •  Growth hormone - Pituitary dwarfism
  •  Erythropoietin - Anaemia
  •  Interferons - viral infections
  •  Interleukin 2 - Cancer
  •  Clotting factor VIII - Haemophilia A
  •  Clotting factor IX - Haemophilia B
  •  Monoclonal antibodies - Infectious diseases
  •  Tissue Plasminogen factor - Heart attack
Enzymes:
 Enzymes have also been produced from cloned genes. Lets have the names of such enzymes and their uses: 
  •  Proteases-  manufacture of detergents, meat tenderisers.
  •  Amylases - manufacture of beer, bread and textiles
  • Glucoisomerases - to make corn syrup, which is sweeter than sucrose and used to flavour soft drinks
 Antibiotics:
Since the discovery of Penicillin in 1920s, more than 6000 antibiotics have been isolated from various microorganisms and have resulted in an enormous improvement in human health. Research is in progress to genetically engineer biosynthetic pathways for the synthesis of antibiotics. Novel antibiotics have also been obtained through genetic manipulation.Some of the common antibiotics and their source organisms are as follows:
  • Tetracyclin -  Streptomyces sp
  • Chlorotetracycline - Streptomyces auriefaciens
  • Chloramphenicol -  S. venezuelae
  • Cycloheximide - S. griseus
  • Streptomycin - S. griseus
  • Cephalosporin - Cephalosporium acremonium
  • Penicillin - Penicillium chrysogenum
 Vaccines:
Bioengineered vaccines have been developed for rabies and hepatitis B. A gene for the antigen protein is inserted into a plasmid and the bacteria containing recombinant DNA then generate large quantities of the protein. The protein is added to the vaccine. Antibodies immediately form against the antigen when vaccinated.

9/16/2016

TNPSC Group 4 Model questions with answers

9/16/2016 0
TNPSC Group 4 Model questions with answers
1.What is the name of the new drug developed by scientists recently as an alternative to antibiotics? Name the drug that is supposed to be an alternative for antibiotics?
(A) Orbactiv
(B) Dalvance
(C) Sivextro
(D) Staphefekt
Answer: (D)

2. Inertia is a property of a body by virtue of which the body is
(A) Unable to change by itself the state of rest.
(B) Unable to change by itself the state of uniform motion in a straight line.
(c) Unable to change by itself the direction of motion.
(D) Unable to change by itself the state of rest or uniform motion in a straight line.
Answer: (D)

3.On 11 February 2016 The LIGO Scientific Collaboration announced the detection of -
(A) electromagnetic waves
(B) seismic waves
(C) gravitational waves
(D) radio waves
Answer:(C)

4.Which one of the following is the powerhouse of a cell?
(A) nucleus
(B) chloroplast
(C) mitochondrion
(D) none of the above
Answer: (C)

5. Water potential of pure water is
(A) zero
(B) one
(C) negative
(D) two
Answer: (A)

6.The SI unit of charge is __________.
(A) Ampere
(B) Coulomb
(C) Ohm
(D) Volt
Answer: (B)

7. Who coined the term cell?
(A) Golgi
(B) Robert Hooke
(C) Robert Brown
(D) Porter
Answer: (B)

8. Iodine crystals can be separated from sand by-
(A) sublimation
(B) decantation
(C) suspension
(D) none of the above
Answer:(A)

9. The respiratory problem most common in smokers is
(A) tuberculosis
(B) emphysema
(C) asthma
(D) cancer
Answer:B

10.The distance between the two points depends upon-
(A) shortest path
(B) direction
(C) motion
(D) the path chosen
Answer: (D)

11/17/2015

TNPSC Study Materials in Tamil Medium - Biology - Free Download

11/17/2015 0
TNPSC Study Materials in Tamil Medium - Biology - Free Download
Free Download - General Knowledge in Biology in Tamil Medium Notes: In these materials are very helpful for preparing TNPSC Examination like Group 2 (Interview and Non - Interview) post. TNPSC Study Materials for General Knowledge Prepared by P.Robert Prabu
P.G.Assistant in zoology

All competitive Exam
(TNPSC UPSC/SSC/TET/TRB/RRB)


Free Download Click Here

11/16/2015

TNPSC Group 2 A Study Materials in Tamil Medium - Biology - Free Download

11/16/2015 0
TNPSC Group 2 A Study Materials in Tamil Medium - Biology - Free Download
Free Download - General Knowledge in Biology  Notes: In these materials are very helpful for preparing TNPSC Examination like Group 2 (Interview and Non - Interview) post. TNPSC Study Materials for General Knowledge Prepared by Akash IAS Academy Coaching Centre

All competitive Exam
(TNPSC, UPSC, SSC,TET,TRB,RRB)


Free Download Click Here