for BLAS

1. Principle of independent assortment.

the law states that the agaenes of different characters located in different pairs of chromosomes are independent of one anotrher in theeir segregation during gamete formation ( meiosis) . the principle of independent assortment can also be defined as “ if we consider the inheritance of tow or more genes at a time their distribution in the gametes and in progeny of subsequent generations in independent of each other.

in the experiment of dihybrid cross between the round yellow and wrinkled green seed plants, we can get the emergence of new characters like round green and wrinkled yellow seed plants. these new characters in combination were not present in the parents.we have the ratio of the dihybrid cross as follows. The round yellow:round green:wrinkled yellow:wrinkled green is 9:3:3:1 in the F2 generation. this showed that the factors responsible characters are separated during the segregation and they are free to combine with any other of the factors. they combine haphazardly. there is no any hard and fast rule for their combination. this is known as principle of independent assortment.

Wildlife conservation

In fact, it refers to any living organisms(animals and plants), micro organisms living in its natural habitat. These are free from human check and interference. So it excludes the cultivated plants and domesticated animals. It is renewable natural resource.

Necessity for wild life conservation

• Helps in maintaining the balance of nature.
• Use commercially to earn foreign exchange if linked with tourism- ecotourism.
• Study by naturalists, biologists, help in conservation
• Provides means of sports and recreation.
• Cultural asset – deep rooted effect on art, sculpture, literature and religion.

Reasons for depletion of wildlife

• Absence of cover or shelter
• Deforestation for cultivation, urbanization etc, reduction in area for free movement, retard reproduction capacity
• Destruction of wild plants for timber, charcoal, firewood; deprive wild animals from most palatable food, affects survival.
• Pollution – noise, pesticides
• Natural calamities – flood, drought, volcanic eruption etc.
• Poaching – food, hide, fur, plumage musk, tusk and horn etc.
• Hunting – recreation.

Some terms

Extinct – the species not definitely reported during past 50 years in wild condⁿ example pink headed duck – suspected to be extinct.

Endangered - if trend of loss of wildlife species contineus at the same rate, species would be in immediate danger of extinction mainly due to habitat loss. Example Panthera tigris, Elephus maximus, Bengal florican etc

Vulnerable - number decreasing due to over exploitation, destruction of habitat, likely to be endangered in near future. Example Asiatic wild dog, Himalayan Black bear etc

Rare - the popⁿ of wild life at risk but not endangered or vulnerable, popⁿ localized within extensive area, example Imperial eagle, Rufous necked Hornbill etc.

Threatened – general term to denote species that are endangered, rare or vulnerable, insufficiently known

IUCN – International Union for conservation of Nature and Resources 1948, head quarter in Switzerland. Red data book – compiled by IUCN , list of endangered spp

WWF world wildlife fund 1961

CITES Convention of International Trade of Endangered species of fauna and flora 1973

Wildlife management

• Habitat management, establishment of National Parks, Reserves, Sanctuaries etc
• Breeding in captivity – ginko and metasequiria survival in captivity only
• Reintroduction- rhinoceros reintroduced in Berdia
• Mass education
• Promulgation of laws

Protected areas in Nepal

ü Until 1950, rich in flora and fauna

ü Adverse effect on wildlife due to increase in human popn, used forest for cultivation and housing

ü Destroyed forest for economic benefit, rhinoceros killed for horn, tiger for skin, deer for meat

In 1970, Royal Chitwan National Park and Langtang National Park established.

In 1973, law passed to set up more National Parks and wildlife reserves.

National Park –

o It is the reserved area set aside for conservation, management and utilization of animals and vegetation.

o In this area, soil, principal geographic areas, landscapes are also managed properly. Entry into NP is restricted without permit and guarded by army

o Animal hunting, cutting of plants etc are strictly prohibited. Grazing of domestic animals and construction of houses are also not allowed.

o All NP are managed by Dept of National Parks and wildlife conservation (DNPWC)

Khaptad NP

Area 225 Km², established in 2042 BS

Location mid mountain region of far western Nepal

Common trees – chirpine, spruce, fir, maple birch, rhododendron

Common fauna – leopard, himlayan black bear, musk deer, ghoral, Himalayan tahr

Lake Rara NP

Area 106 Km², established in 2032 BS

Location North west Nepal

Common tree coniferous forest dominated by blue pine ideal habitat for Musk deer

Common fauna musk deer, Himalayan black bear, leopard. Ghoral, himalayn tahr, wild boar, impeyan pheasant, kaliz

Royal Berdia NP

Area 968 Km² established 2045 BS

Location Far western Terai

Common tree – nearly 70% dominated by sal forest, excellent habitat for endangered animal like rhinoceros

Common fauna wild elephant, tiger, swamp deer, black buck, gharial, Dolphin

Shey Phoksundo NP

Area 3555 Km² largest established 2040 BS

Location mountain region of western Nepal

Common tree blue pine spruce, poplar, deodar quercus provide habitat for snow leopard

Common fauna blue sheep, ghoral leopard, wolf jackal Himalayan mouse hare langur

Royal Chitwan NP

Area 932Km² established 2030 BS

Location sub tropical inner Terai lowland, world heritage site in 1984

Common tree- sal

Common fauna - Park renowned for one horned Rhino, tiger, gharial crocodile gaur, wild

elephant four horned antelope striped hyena, pangolin, sambar deer, chital etc

Langtang NP

Area 1710 Km² established 2032

Location central Himalayan region

Common fauna wild dog, red panda, musk deer rhesus monkey, langur etc

Sagarmatha NP

Area 1148 Km² established 2032 BS

Location North eastern part , includes the highest peak Mt. Everest

World heritage site in 1979

Common tree pine hemlock forest, fir, juniper

Common fauna Himalayan tahr, ghoral musk deer

Makalu Barun NP

Area 1500 Km² established 2047 BS

Location Eastern part

Some unique pocket of plant and animals 47 varieties of orchid, 67 spp of medicinal plants, rhododendron

Red panda, musk deer, clouded leopard, snow leopard, barking deer, more than 400 spp of birds

Shivpuri NP

Previously Shivpuri watershed management and wildlife reserve

Area 144 Km²

North of Ktm habitat for Himalayan plants and many birds

Wildlife reserves

Royal Suklaphanta WR

Area 155 Km² established 2031

Southeastern part

Habitat for swamp deer, wild elephant, tiger, leopard, chital etc

Persa WR

Area 499 Km² established 2040 BS

Provide habitat for wild elephant, tiger leopard, wild dog etc

Koshitappu WR

Area 175 Km² established 2039 BS

Location eastern flood plain of Saptakoshi river

Habitat for last surviving popn of wild buffalo Arna, wild boar, spotted deer, ghoral

Dhorpatan Hunting reserve

Area 1375 Km² established 2041 BS

For purpose of spot hunting guarded by army

Habitat for blue sheep, leopard, ghoral, black bear

Annapurna conservation area

Area 7000 Km² established 2043 BS

Managed under King Mahendra Trust for Nature conservation

Blue sheep, snow leopard

Makalu Barun conservation Area

Area 830 Km² established 2047 BS

Birds, medicinal plants

Kanchanjunga conservation area

for BLAS

Origin of new characters

Heredity is the presence of characters in the off springs which are present in the parents. These characters are directly transmitted to children from parents. The children thus get some characters from father and some other characters from mother. Some children get more of the characters from father and less from mother and vice versa. So, any child is not the photocopy of the father or mother. The child is little bit different from the father as well from the mother.

In the sexually reproducing animals including human beings, at the time of gamete formation, there is meiosis. During this cell division meiosis, the chromosomes number is reduced to half. For example, in case of human beings, there are 23 pairs of chromosomes. It is said to be Diploid number of chromosomes, denoted as 2n. In the sperm and ova(eggs), there are only 23 chromosomes. This number of chromosomes is said to be Haploid number of chromosomes and denoted as n. At the time of fertilization, the chromosomes of sperm and egg together make Homologous pairs of chromosomes and thus make Diploid number of chromosomes. During the process of formation of Homologous pair of chromosomes, there is crossing over to make the new set of chromosomes. This new set of chromosomes are little bit different from the those of parents. This new set of chromosomes are responsible for the origin of new characters in the off spring or children.

The new set of chromosomes are formed because of meiosis. The pattern of transmission of characters depend on the way the new set of chromosomes are formed. The pattern of transmission of characters in the off spring is studied in Genetics. This term Genetics was first used by W Bateson in 1905. The foundation of Genetics was laid in 1865 by Gregor Johann Mendel. For his overriding contribution in Genetics he is called as Father of Genetics.

Biography of Gregor Mendel

Gregor Mendel was born on 22 July 1822 at Heinzendorf of Silesian village in Austria. He joined Augustinian monastery at Brunn in Austria in 1843. He was sent to University of Vienna to study Natural Science and Mathematics. He returned to Monastery in 1853. He conducted research on common garden pea plant (Sativum pisum) for eight years from 1956 to 1864. Mendel presented data and conclusion derived from his experiments in a paper entitled “ Experiments in plant hybridization” which was read before Brunn Natural History Society in 1865 and was published in Annual proceedings of Natural history Society in 1866. His work was not recognized in his life. Unrecognized and bitterly disappointed , he died in 1884. Mendel’s observations went unnoticed on account of

• He published his work in an obscure journal.
• Failure of he scientists to notice his work because scientific world was at that time busy in the controversy arisen by the Darwin’s theory of origin of species.
• His ideas were ahead of his time as the ignorance was prevalent in that period about cytological basis of heredity.

In 1900, three eminent biologists Hugo de Vries of Holland, Karl Correns of Germany and Eric Von Tshermak of Australia working independently on heredity discovered the same phenomena originally uncovered by Mendel. Thus the genius of Mendel came to be discovered after 16 years of his death. Mendel for his great contribution is now famous as “Gather of Genetics”.

Mendel’s experiment

Mendel selected garden pea (Pisum sativum) as plant material for his experiment since it had following advantages.

• Possess many varieties with well defined characters.
• Flowers are bisexual and can pollinated easily.
• Easily be grown and readily be crossed.
• Very short life span, many generations formed.
• Hybrid pea plants are fertile.
• Flowers completely closed by petal, so plants predominantly self pollinating and self fertilizing.

Reasons for Mendel’s success

• Studied the inheritance of one character at a time.
• Carried out experiments to F2 and F3 generations only.
• Maintained statistical records, analyzed carefully.
• Selected pure line parent plants.
• All possible precautions taken to prevent self pollination.
• Even reciprocal crosses conducted but no change in the expected ratio of off springs.

Seven pairs of contrasting characters of pea plant used by Mendel

Trait dominant recessive

1. Seed color yellow green
2. Seed shape round wrinkled
3. Pod color green yellow
4. Pod shape inflated constricted
5. Flower color purple white
6. Flower shape axial terminal
7. Plant height tall dwarf

These seven pairs of contrasting characters of pea plant mean that if one character is expressed the other is not expressed. If the character tallness is expressed the other character dwarfness cannot be expressed. In the same way, if dwarfness is expressed, the other character tallness is not expressed.

Some basic terms used in inheritance studies

Gene or Factor

Mendel called it factor which carry the character from the parent to offspring. In the modern sense an inherited factor that determines a biological character of an organism is called gene. This is the function unit of hereditary material. It is a segment of DNA. Gene is equivalent to the factor of mendel.

Allelomorphs or allele

Allele is abbreviated form of allelomorphs, which means one form or the other. It indicates the alternative forms of the same gene. Each character has two determiners called factor. In pure tall or pure dwarf plant, same allele is duplicated like TT or tt. But in the hybrid tall plant both alleles are present like Tt. An organism having same allele or two identical alleles is known homozygous and an individual with different alleles is called the heterozygous. For example an organism with both TT or tt is called homozygous and an organism with Tt is called heterozygous.

Homozygous plants are genetically pure or that character. They give rise to offspring having same character on self breeding. The heterozygous hybrid plants do not breed true on self fertilization. The heterozygous plants on self fertilization produce both tall and dwarf plant.

Homozygous organism bear either dominant or recessive alleles and never both. Where as heterozygous organism bear both dominant(T) and recessive(t) alleles. The homozygous organism(plant) produces one types of gametes either T or t only. But heterozygous organism produces two types of gametes nearly half with T and another nearly half with t. The homozygous plants do not show vigor but the hybrid or heterozygous plants show extra vigor.

Genotype and phenotype

It is the genetic composition of an organism. It can be like TT, Tt or tt for a particular character. The genotype can be ascertained from ancestry or progeny of individual. On the other hand, phenotype is character which can be observed from the outside like the tall plant or dwarf plant. Phenotype is expressed like form, sex, color, behaviour etc. phenotypes of organism is expression or observable structural traits or characters produced due to interaction of genes and environment. In some cases, the phenotype is not visible from outside. For example, the blood groups like Blood group A, B, O and AB and Rhesus Factor like Rh +ve or –ve is not expressed outside.

Monohybrid and dihybrid cross

In the monohybrid cross, Mendel considered only one pair of contrasting characters like tallness and dwarfness of plant. Similarly, the other characters like round or wrinkled seed or yellow or green seed etc. can be considered but only one pair of the contrasting characters. The other characters are not taken into consideration. In case of dihybrid cross, two pairs of contrasting characters are taken into consideration at the same time like the yellow or green and round or wrinkled seeds.

Reciprocal cross

The reciprocal crosses involve tow crosses concerning the same characteristics but with reversed sex. For example, if in first cross, A is as the female and B is as male, then in the second cross A is as male and B is as female.

The interpretation of Mendel’s results

The principles of inheritance as given by Mendel are as follows.

1. Principle of Dominance

Out of two contrasting characters only one is expressed itself in an individual. The factor which is expressed is called dominant while the other which has not shown its effect is termed as recessive. In monohybrid cross, when homozygous (true breed) tall pea plant is crossed with homozygous dwarf plant, all the plants appeared in F1 generation are tall although they receive both factors (Tt) T from tall plant and t from dwarf plant. In the F1 generation, the character of t is not expressed. The character which is expressed in the F1 generation is called the dominant character and the character which is not expressed in F1 generation is called the recessive. The factors responsible for certain character is always found in the pair like TT or Tt or tt. To these Mendel’s factors, Danish botanist Johansson introduced the term gene in 1909.

Importance of principle of dominance - the phenomenon of dominance is of practical importance as the harmful recessive characters remain hidden by normal dominant character in hybrids. In human beings, a form of idiocy, diabetes and hemophilia are recessive characters.

2. Principle of segregation ( purity of gametes)

The law of segregation states that when a pair of contrasting factors or allelomorphs or genes are brought together in a hybrid(heterozygote) these factors do not blend or mix up but simply associate themselves and remain together and separate at the time of gamete formation.

3. Principle of independent assortment.

for BLAS

Flood

It is overflow of water from river, stream etc into nearby land. It occurs when vegetation and soil can absorb all of the rain water.

Causes

o Heavy rain fall during monsoon.

o Snow melt

o Glacier lake outburst (GLOF) common in mountainous country

o Urbanization , ground surface becomes impermeable to water.

o Earthquake tidal moves generated by quake cause flood , tsunami.

Types

 Periodic flood which occur naturally in many river during the monsoon.

 Flash flood which occur rapidly flood rises and falls without warning. It is resulted from heavy rain over a small area or GLOF or dam failure.

Effects

 Destruction of agricultural crops like rice , potato etc

 Destruction of property, disease like cholera typhoid dysentery etc.

 Death loss of life of man and animals

 Loss to government, damage to roads, buildings, telephone electrical infrastructure.

Land slide

Down ward and upward movement of slope forming materials like rock soil etc. It is caused by falling sliding flowing at faster rate. It occurs in steep slopes where hard and heavy rock overlies softer ones.

Causes

o Natural factor, steep slopes, development of weak rocks, high weathering of rock, heavy rain fall seismic activity.

o Anthropogenic factors, deforestation, over grazing, agricultural activity on steep slope, construction of roads, building canals etc are artificial factors which cause landslides.

Effects

 High amount of fertile soil washes down leaving unproductive land or area.

 Destroy ecosystem of area.

 Destroy road and building.

 Blocks stream, river etc cause huge flood.

 Landslides in public settlement take life and property.

 Terrestrial animals are highly affected.

 Streams or river may dry out or appear in improper places.

Earth quake

Sudden temporary vibrations set up on earth’s surface ranging from a faint tremor to a wild motion. The motion is due to sudden release of energy stored inside the earth surface. It lasts from a few seconds to a minute. Sometimes the vibrations are so feeble that we cannot feel them.

Terms

 Focus/hypocenter - it is the point under the earth from where the earth waves originate the earth quake.

 Epicenter – it is the point on the surface of earth directly above the focus of a earth quake. This is the most affected area during the earth quake.

Causes

o Natural cause

 Tectonic cause - about 95% if the earth quake are due to crack or fracture developed on a rock by accumulation of more stress, dislocation of rock and waves of energy are sent out through earth.

 Non tectonic – explosion of volcano etc.

o Anthropogenic - some earth quakes are caused due to human activity like underground explosion of bombs, passage of trains and tank, heavy machinery in indusrial area, extraction of mines, minerals and fossil fuels from earth’s crust, fracture of dam and collapsing of large buildings etc.

Effects

 Due to vibrations of ground, the infrastructure got heavily damaged. It can take life of people.

 Earth quake also changes geological structures of an area and destroys road, water and gas pipes.

 Responsible for fire due to fallen wires and broken gas pipes.

 Earth quake below sea generates seismic waves causes tsunami.

 Causes landslides and flood.

Fore shock- minor shock which occur before major earth quake.

After shock- minor but destructive earth quake which occur after major earth quake.

Seismograph – it is the graphic representation of measurement of origin and frequency(the magnitude of earth quake).

The largest earth quake so far measured is 8.6 in Richter scale.

Prof. Charles Richter of California proposed a scale of earth quake magnitude in 1935 AD to measure the quantity of energy released during earth quake.

Role of forest

1. Timber and wood collection for building and industries.

2. Firewood consumption, rural people about 80% depend upon fire wood.

3. Industrial raw material like paper industry lokta plywood dyes resins gum turpentine etc.

4. Ecological balance.

5. Maintenance of global climate, absorb CO2.

6. Check soil erosion, landslide, land degradation.

7. Sources of medicinal plants, essential oil, used in soap cosmetics and pharmaceuticals etc.

8. Habitat for wild animals

9. Beauty, natural beauty tourism industry, visit forest for peace and recreation.

10. Fodder

11. Ornamental and religious

12. Fruits

Role of river

Water is the most important component for life. Cells and tissue of animals and plant body contain 60 to 90 % of water. Plants use water as raw material for photosynthesis, water essential for cooking and washing, bathing etc.

1. Sources for water supply in urban area.

2. For irrigation (agriculture)

3. Power industry (boiler)

4. Habitat for fresh water and marine water animals.

5. Beauty

6. Hindu rituals cremation in the bank of river.

7. Generate electricity

8. Water mill

9. Control pollution

10. Civilization, settlement eg Nile river.