UNIT-(II)
Economic Botany
Cereals: rice, wheat and maize:
1.RICE (Hindi – Chaval or Dbari):
Botanical Name: Oryza sativa L.
Family: Gramineae or Poaceae
ECONOMIC USES:
1. Rice is the chief cereal used as staple food in most of the parts of the world.
2. Its fruit is a caryopsis.
3. It is an annual grass which grows luxuriantly in deep waters.
4. The inflorescence is a long panicle with ovate or oblong spikelets.
5. Caryopsis is oblong and angular. It remains tightly enclosed in lemma and palea.
6. Grains contain a large amount of starch, fat and proteins.
7. It is also used in the preparation of many alcoholic beverages.
8. Hats are prepared from the fibres obtained from its stem.
9. Paper, mats and boards are also prepared from rice.
10. Rice-bran oil is used for soaps, cosmetics and also as an anticorrosion oil.
11. Rice husk is used for making activated carbon, sodium silicate and silicon, and also as fuel, packing material and animal feed.
12. West Bengal, Bihar and U.P. are the chief rice- producing Indian states.
2. WHEAT (Hindi – Gehun):
Botanical Name: Triticum aestivum L. emend. Thall.
Family: Gramineae or Poaceae
ECONOMIC USES:
1. It is a cereal crop of family Gramineae.
2. It is the most common food plant.
3. The plant attains a height of 2-5 feet.
4. The inflorescence is a spike of spikelets. The spikelets are borne of a zigzag axis.
5. The fruit is a caryopsis.
6. Each grain consists of an outer husk, the aleurone layer containing protein, the endosperm having starch, and the embryo.
7. Wheat flour is used for making bread, biscuits, cakes, pastry and other similar articles. Wheat is also used in the manufacture of beer and other alcoholic beverages.
8. Fruit contains a single endospermic seed which contains many minerals, including Mg, Mn, Cu, Fe and Zn.
9. Wheat straw is used as a fodder for catties and for seating the chairs, mattings, hats, etc.
10. Wheat straw pulp is used for preparing writing-, printing- and wrapping paper, and straw board.
11. In India, wheat is grown mainly in Punjab, U.P., Haryana, Madhya Pradesh, Maharashtra, Rajasthan and Bihar.
12. Important wheat-producing countries are U.S.A., Russia, Australia, China, India, etc.
3.MAIZE (Hindi – Makai):
Botanical Name: Zea mays L.
Family: Gramineae or Poaceae.
ECONOMIC USES:
1. It is an annual cereal, attaining a height of 3 to 15 feet.
2. It is the largest amongst the cereals.
3. The stem is jointed, the leaves are large and the aerial prop roots are present in addition to the well-developed fibrous root, system.
4. Flowers are of two types, i.e., terminal tassel bearing the male flowers and cob or ear bearing the female or pistillate flowers (Fig. 71).
5. Styles are long and silky.
6. Cob is covered by large number of leafy bracts.
7. The fruit is a caryopsis consisting of hull (6%), protein or aleurone layer (8 to 14%), endosperm (70%) and embryo (11%).
8. Grains are used by man as well as animals for food.
9. Corn flakes, com starch, com syrup, com oil, dextrins and industrial alcohols are some of the maize products.
pulses: Bengal gram, green gram, black gram:
1.BENGAL GRAM (Chick Pea):
Botanical Name : Cicer arientinum
Family : Leguminoceae
Bengal Gram is the most important rabi pulse crop grown in India. Rank first in area as well as in production of gram.
ECONOMIC USES:
1. Tender leaves of young gram crops are used as vegetable.
2. The grain is eaten in raw or boiled as vegetable.
3. The grain is parched and eaten as futanas.
4. Dal is grounded in flour and used in preparation of Besan or Zunka, Shev, Chakli, Bhaji etc.
5. It is also used for preparation of sweet meats like pura-poli, laddu,mysorepak, bundi, jilebi etc.
6. The malic acid (Amb) is collected from plants which have medicinal value against stomach ache.
7. The broken grains are largely fed to horse and the dried leaves and stalks are used as fodder for cattle.
8. It is a good source of protein and content 16-19% protein.
9. Germinated seeds are good source of vie-E.
2.BLACK GRAM (Urad Dal):
Botanical Name: Vigna mungo(Linn.) Hepper.
Family: Leguminoseae.
ECONOMIC USES:
1.Vigna mungo is an important pulse crop grown throughout India.
2.It is grown in an area of about three million hectares in India.
3.Annual production of urdbean in India is about 1.3 million tonnes.
4.It is mainly used as 'dal' and in preparation of many dishes in our diet.
5.In southern parts of the country, it is used in preparation of some special dishes.
6.It is very rich in protein containing about 25 per cent protein in its seed and is the richest in phosphoric acid among pulses.
7.Besides, this green fodder of urdbean is very nutritive and is specially useful for milch cattle.
8.It can also be used as green manure.
9.It also acts as cover crop and its deep root system protects the soil from erosion.
10.Urdbean being leguminous has the capacity to fix atmospheric nitrogen and thus helps in restoring the soil fertility.
3.GREEN GRAM (Myng bean):
Family: Fabaceae
Botanical name: Vigna radiata
ECONOMIC USES:
1. Green gram is consumed as food in several ways. In India it is mostly used as dal along with the cereals.
2. The flour of gram is used in the preparation of biscuits, namkin, sweets and for other purpose.
3. The germination grains are consumed as nutritious food for good health.
4. The grains and plant residues are used as cattle feed.
5. This is an ideal and important crop for rotation with cereals and also used for green manuring purposes.
Oil seeds: mustard, groundnut, sunflower:
1.MUSTARD (Rape seed):
Family : Cruciferae
Botanical Name : Brassica juncea
India occupies the first position both in area and production of rape seed and mustard.
ECONOMIC USES:
1. Rape seed and mustard give edible oil which is used as cooking medium in north India.
2. Seed is used as condiment in the preparation of vegetable and curries.
3. Split seed (Mohari dal) and oil is used for pickling.
4. The leaves of the young plants are used as vegetable.
5. Oil cake is fed to cattle.
6. Oil content mustard varies from 30 to 48%.
7. Oil content of white mustard varies from 25 to 33%.
2.GROUNDNUT (Pea nut):
Botanical Name: Arachis hypogaea I.
Family: Papilionaceae.
ECONOMIC USES:
1. It is a creeping or bushy annual plant with a characteristic habit of ripening its fruits underground (Fig. 73).
2. The plants are used for forage and stock-feeding.
3. Nuts are used commonly in winter season as such, or in the preparation of candy or peanut butter.
4. From the seeds or nuts, peanut oil is obtained. Refined oil is used for cooking purposes, while the inferior grades are used for soap making and as illuminants.
5. The hydrogenated oil yields the ‘vegetable ghee’.
6. Oil cake is used as a stock feed for catties.
7. Ardil, a synthetic fibre, is manufactured from the proteins found in groundnuts.
8. Groundnut has high nutritive value. It is highly rich in proteins and vitamins, particularly vitamin B and nicotinic acid.
9. High quality oil is used in pharmaceutical industry.
10. Groundnut shells are used for manufacture of cork substitutes and coarse boards.
3.SUNFLOWER (Kusumbha):
Family : Compositae
Botanical Name : Carthamus tinctorius
Safflower oil does not increase the cholesterol level in human blood and hence good for health.
ECONOMIC USES:
1. Safflower is most important rabi oilseed crop grown in Maharashtra.
2. It is grown mainly for edible oil and sometimes for dye purpose.
3. The oil is good for heart patients as it contains polyunsaturated fatty acids.
4. It is drying oil and hence used in manufacture of paints, varnishes, water proofing material, adhesives for glass etc.
5. The oil cake from decorticated seed is fed to cattle.
6. The leaves of young plants are used as vegetable.
7. Red and yellow dye obtained from the flower heads is used for colouring cloths.
8. It is grown as border crop to protect the main crop from domestic animals.
9. Dried stalks are used as fuel or for making paper.
10. Oil content of safflower is about 28 to 30 p.c.
Fibre: cotton, jute:
1.COTTON
Botanical Names:
Gossypium sp. (G. arboreum, G. barbadense, G. berbaceum and G. hirsutum).
Family: Malvaceae.
ECONOMIC USES:
1. It is the chief fibre plant which supplies more than 70% of the world consumption of fibres.
2. Fibres occur on the seeds in the form of flattened, twisted and tubular hairs (Fig. 77).
3. Raw cotton consists of cellulose (94%), protein (1.3%), pectic substances (0.9% to 1.2%), water (0.6%), sugar (0.3%) and some pigment traces.
4. Chief use of the cotton is in the textile industry. Other uses include stuffing of pillows, cushions, and also in rubber tyre fabrics.
5. Short fibres, called linters or fuzz, are used for superior acetates and viscose rayons, cellulose ethers and esters, and nitrocellulose lacquers.
6. Hull, the outer covering of cotton seeds, is used for cattle feeding, fertilizers, fillers in plastics, and manufacture of insulating materials.
7. A most important semidrying oil (cotton seed oil) is obtained from the seeds of cotton. It is used as a cooking oil. Other uses of this oil include in the preparation of soaps, paints and varnishes, washing powders, artificial leather, glycerine, nitroglycerin, etc.
8. Seed cake is used as fertilizer and as cattle feed.
9. Gossypium roots are used in some fevers.
10. Its seeds are used in diseases like gonorrhoea, catarrh and gleet.
11. Leaf juice of G. berbaceum is used in scorpion and snake bites.
12. Cotton fibre is also used in paper industry, specially in preparing fine quality paper.
2. JUTE (Hindi – Pat or Titapai):
Botanical Name: Corcborus capsularis, C. olitorius.
Family: Tiliaceae.
1. It is a chief fibre-yielding annual shrub.
2. Fibres are obtained from the stem of two species, i.e., C. capsularis and C. olitorius.
3. It is a bast fibre, obtained from the secondary phloem by the process of retting.
4. Jute is cultivated in West Bengal, Assam, Orissa, Bihar and U.P.
5. Jute fibre is used in making carpets, coarse material, twine, gunny bags, paper and many similar articles.
6. Jute forms the base of linoleum and wool carpet industry.
7. High quality grease-proof paper is prepared from the fibres of jute sticks. It is used commonly is confectionery industry for wrapping greasy materials.
8. Dried leaves of C. capsularis are also used as a remedy for dysentry.
9. Besides India, Bangladesh is also a chief jute- producing country of the world.
Beverages: coffee, tea:
1.COFFEE:
Botanical Names:
Coffea arabica (Arabian Coffee); C. canepbora syn. C. robusta (Congo Coffee); C. liberica (Liberian Coffee).
Family: Rubiaceae
ECONOMIC USES:
1. It is an important non-alcoholic beverage, like tea.
2. More than 90% coffee is obtained from the berries (Fig. 95) of Coffea arabica.
3. Coffee beans are roasted for developing the aroma, flavour and colour and finally ground before they reach to the consumer.
4. “Beans” contain caffeine (0.75 to 1.5%), a volatile oil, glucose, dextrins, proteins and a fatty oil.
5. Caffeine provide stimulating effect while the volatile oil (caffeole) is responsible for aroma and flavour.
6. Leaves and fruits of Coffee also contain some alkaloids.
7. In India, C. arabica is grown in Nilgiris and Kamataka.
8. Seeds of C. canepbora (syn. C. robusta), a robust evergreen shrub, are used in making “instant coffee”.
2.TEA:
Botanical Name: Camellia sinensis (L). O. Kuntze (Syn. Thea sinensis L.)
Family: Theaceae
ECONOMIC USES:
1. It is the most common non-alcoholic beverage, used by more than one-half of the world’s population.
2. It is obtained from the dried leaves of Camellia sinensis, a native of Assam or China.
3. Tea plant is a small shrub with leathery, lanceolate leaves having serrate margin and many oil glands (Fig. 94).
4. A volatile oil, tannin (13 to 18%), and an alkaloid theine (2-5%), are present in tea.
5. Tea leaves, when infused in hot water, dissolve their alkaloid and oil, and the beverage thus resulted has a stimulating effect. If boiled for a longer period, tannin dissolves making the beverage less beneficial.
6. India is a leading tea-exporting country.
7. For preparing green tea, the leaves are steamed and dried without fermenting, while for black tea the leaves are withered, rolled, fermented and dried.
8. Tannins of tea waste are used in plywood industry.
9. Assam, Darjeeling, Nilgiris, Dehradun and Kumaon are the main tea-producing regions in India.
UNIT-(III)
NUMERICAL CHROMOSOME ABERRATION:
In some case, number of chromosome in an affected person can are increased or decreased. Following types of chromosomal abnormalities are produced due to change in chromosomal number.
(A)ANEUPLOIDY:
The random abnormal number of chromosomes in the animals is called as aneuploidy. Aneuploidy is mostly caused by non disjunction. The members of a pair of homologous chromosomes do not move apart properly during non disjunction. Therefore, the sister chromatids fail to separate at meiosis II. In these cases, one gamete receives the same type of chromosome and another receives no copy. The other chromosomes are usually distributed normally. If these abnormal gametes unite with a normal one, the offspring will have an abnormal chromosome number. It causes aneuploidy.
Fig: Non-disjunction
Types of aneuploidy:
There are following types of aneuploidy:
1.Monosomic: (2n — I):
If a chromosome is missing the aneuploidy is monosomic. Therefore, the cell has 2n — I chromosomes. Human genetic disorders arising from monosomy are:
(a) XO (Turner syndrome)
(b) cri du chat syndrome: It is a partial monosomy caused by a deletion of the end of the short (p) arm of chromosome 5.
(c) I p36 Deletion Syndrome: It is a partial monosomy caused by a deletion at the end of the short (p) arm of chromosome I.
2.Disomic:
A disomy is the presence of a pair of chromosome. For diploid organisms, such as humans, it is the normal condition. For organism that are normally triploid or above, disomy is an aneuploidy. It can occur in cells that are normally haploid, such as gametes. In uniparental disomy, the disomy means two copies of the chromosome from one of the parents (with no contribution from the other parent).
3.Trisomic (2n + I):
If the chromosome is present in triplicate in the fertilized egg the aneuploid cell is called trisomic. The cell has a total of 2n + I chromokome. There are two types of trisomy:
(a) Partial trisomy: In this case, part of an extra chromosome is attached to one of the other chromosomes. Sometimes, one of the chromosomes has two copies of part of its chromosome.
(b) Mosaic trisomy: In this case, an extra chromosomal material exists in only some of the organism’s cells.
The most common types of trisomy that survive without spontaneous abortion in humans are:
• Trisomy 21 (Down syndrome)
• Trisomy 18 (Edwards syndrome)
• Trisomy 13 (Patau syndrome)
• Trisomy 9
• XXX (Triple X syndrome)
• XXY (Klinefelter’s syndrome)
• XYY (XYY syndrome)
4.Tertrasomics:
If the chromosome is present in tetrad form in the fertilized egg the aneuploid cell is called tertrasomics for that chromosome. The cell has a total of 211 + 2 chromosomes.
5.Nullisomics:
If a set of chromosome is missing the aneuploidy is nullisomics. Therefore, the cell has 2n —0 chromosomes.
Affects of aneuploidy:
Aneuploidy is produced in sperm or egg. Later it is transmitted to the zygote. Mitosis transmits the aneuploidy to all embryonic cells. Such organism may not survive. If the organism survives, it becomes abnormal. Non disjunction can also occur during mitosis. The early aneuploid condition is passed to a large number of cells by mitosis. It has greater effect on the organism.
(B)POLYPLOIDY (euploldy):
A condition in which the organisms have more than two complete sets of chromosomes is called polyploidy. The natural occurrence of polyploids in the animal kingdom is extremely rare. But polyploidy can be induced experimentally in certain animals, such as frogs and rabbits. It occurs by two ways:
1.Autopolyploidy:
Autopolyploids are polyploids in with chromosomes derived from a single species. It has two forms:
(a) Natural Autopolyploidy: Autopolyploids can arise from a
naturally occurring spontaneous genome doubling (for example potato). Bananas and apples can be found as triploid autopolyploids. The giant tree Sequoia semperviretts or Coast Redwood has a hexaploid (6n) genome. It is a autoallopolyploid (AAAABB). Cabbage is a very interesting example of a fertile allotetraploid crop.
(b) Artificial Autopolyploidy: Polyploidy can be induced in cell culture by some chemicals like colchicine. Colchicine causes chromosome doubling.
2.Allopolyploidy:
Allopolyploids are polyploids with chromosomes derived from different species. Triticale is an example of an allopolyploid. It has six chromosome sets. Four are taken from wheat (Triticum turgidum) and two are taken from rye (Secale cereale).
Types of polyploidy:
There are following types of polyploidy:
(a)Triploidy (3n): They have an extra haploid set of chromosome in each pair. It may be produced by the fertilization of an abnormal diploid egg with sperm produced by nondisjunction.
(b)Tetraploidy (4n): They have increase of one diploid set of chromosome in each pair. Sometimes, there is the failure of a 2n zygote to divide after replicating its chromosomes. Subsequent mitosis will then produce a 4n embryo.
(c)Mosaic polyploidy: It is more common than complete polyploid animals. In this case, the animals have patches of polyploidy cells.Polyploidy in humans Polyploidy also occurs in humans. But these occur much less frequently. 1 e polyploid conditions observed in humans are triploidy (69.,(XX ) and tetraploidy (92,XXXX). Additional chromosomes contain a large amount of surplus gene product. It causes multiple disease like defects of the heart and central nervous system.
Poly ploid crops:
Polyploid plants are stronger than diploids. In the breeding of crops, those plants that are stronger and tougher are selected. Thus polyploids of many crops are produced:
(a)Triploid crops: banana. apple
(b)Tetraploid crops: wheat, maize, cotton. potato, cabbage. leek. tobacco, peanut
(c)Hexaploid crops: chrysanthemum, bread wheat, oat
(d)Octaploid crops: strawberry, dahlia, pansies. sugar cane.
Some crops are found in a variety of ploidy. Apples. tulips and lilies are commonly found as both diploid and triploid. Daylilies (hemerocallist are available as either diploid or tetraploid.
Some crops are found in a variety of ploidy. Apples. tulips and lilies are commonly found as both diploid and triploid. Daylilies (hemerocallist are available as either diploid or tetraploid.
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