Samacheer Kalvi 9th Science Solutions Chapter 23 Pdf
Tamilnadu Board Samacheer Kalvi 9th Science Solutions Chapter 23: Tamilnadu State Board Solution Class 9 Science Chapter 23 – ECONOMIC BIOLOGY.
Samacheer Kalvi 9th Science Solutions Chapter 23: Overview
Samacheer Kalvi 9th Science Solutions Chapter 23 Pdf
Choose the correct answer.
1.) The production and management of fish is called
Ans: a. Pisciculture
Because, Pisciculture or fish culture is the process of breeding and rearing of fishes in ponds, reservoirs, lakes, rivers and paddy fields.
2.) Which one of the following is not an exotic breed of cow?
- Brown Swiss
Ans: c. Sahiwal
Because, Sahiwal is the indigenous breed of cow.
3.) Which one of the following is an Italian species of honey bee?
- Apis mellifera
- Apis dorsata
- Apis florae
- Apis cerana
Ans: a. Apismellifera
Because, Apismellifera is the exotic variety of Italian bee.
4.) Which one of the following is not an Indian major carp?
Ans: d. Singhara
Because, Singhara is not an Indian major carp.
5.) Drones in the honey bee colony are formed from
- unfertilized egg
- fertilized egg
- both b and c
Ans: a. unfertilized egg
Because, they develop from unfertilized eggs, and their main function is to fertilize the eggs produced by the queen.
6.) Which of the following is a high milk yielding variety of cow?
- Holstein- Friesan
- Red Sindhi
Ans: a. Holstein- Friesan
Because, Holstein-Friesan is the foreign breeds which are having long lactation period.
7.) Which Indian variety of honey bee is commonly used for apiculture?
- Apis dorsata
- Apis florea
- Apis mellifera
- Apis indica
Ans: d. Apisindica
Because, Apisindica is the Indigenous variety of Indian bee.
8.) __________ is the method of growing plants without soil.
d) None of these.
Ans: b) Hydroponics
Because, hydroponics is the method of growing plants without soil, using mineral nutrient solutions in water.
9.) The symbiotic association of fungi and vascular plants is
Ans: c) Mycorhizae
Because, Mycorhizae are the fungi having symbiotic association with the roots of vascular plants and they increase the uptake of phosphorus.
10.) The plant body of mushroom is
d) All of these
Ans: c) Leaf
Because, the plant body of mushroom is leaf.
Fill in the blanks.
1) Quinine drug is obtained from _________.
Ans: Quinine drug is obtained from Cinchona officinalis.
2) Carica papaya leaf can cure __________ disease.
Ans:Carica papaya leaf can cure Apiculture disease.
3) Vermicompost is a type of soil made by __________ and microorganisms.
Ans:Vermicompost is a type of soil made by earthworms and microorganisms
4) __________ refers to the culture of prawns, pearl and edible oysters.
Ans: Aquaculture refers to the culture of prawns, pearl and edible oysters.
5) The largest member in a honey bee hive is the ___________.
Ans:The largest member in a honey bee hive is the F.
___________ is a preservative in honey.
Ans: Formic acidis a preservative in honey.
__________ is the method of culturing different variety of fish in a water body.
Ans: Polyculture is the method of culturing different variety of fish in a water body
III. Say true or false. If false, correct the statement.
1) Mycorrhiza is an algae.
Correct statement: mycorrhiza is a fungi.
2) Milch animals are used in agriculture and transport.
Correct statement: Milch animals are used for obtaining milk only.
3) Apis florea is a rock bee.
Correct statement: Apis Florea is a little bee.
4) Ongole is an exotic breed of cattle.
Correct statement: Ongole is a dual purpose breed of cattle.
5) Sheep manure contains high nutrients than farm yard manure.
Differentiate the following.
1) Exotic breed and Indigenous breed
- Exotic breeds are imported from foreign countries.
- They include Jersey, Brown Swiss and Holstein-Friesian etc.
- These foreign breeds are selected for long lactation period.
- Indigenous breeds are native of India.
- They include Sahiwal, Red Sindhi, Deoni and Gir.
- Milk production depends on the duration of the lactation period. These local breed animals shows excellent resistant to diseases.
2) Pollen and Nectar
- Pollen is the fine powder from the male flower which fertilizes female flower to produce seeds.
- Nectar is the sweet substance which is made by some plants to attract pollinators like butterflies and bees.
3) Shrimp and Prawn
- Prawns have three pairs of claw like legs
- The legs of prawn are longer than shrimp.
- Prawns are the part of dendrobranchiata suborder.
- Shrimp have only one pair of leg.
- The legs of shrimp are shorter than the prawns.
- Shrimps are the members of pleocymata suborder.
4) Farmyard manure and Sheep manure
- It is the mixture of cattle dung, urine, litter material and other dairy wastes.
- It contains 0.5% nitrogen, 0.2% available phosphate and 0.5% available potash.
- It contains higher nutrients than farm yard manure.
- It contains 3% nitrogen, 1% phosphorus pentoxide and 2% potassium oxide.
Match the following.
Sea bass:……….. Marine fish
Pleurotus sps…….Oyster mushroom
Wrighta tinctoria… .Psoriasis
1) What are secondary metabolites?
Ans: The history of medical plants is as old as the history of human beings. Most of the medicine are obtained directly or indirectly from the plants. All the major system of medicines such as Ayurveda, Yoga, Unani, Siddha, Homeopathy AYUSH use drugs obtained from plant and animals. These drugs from medicinal plants are called secondary metabolites
2) What are the types of vegetable garden?
Ans: Olericulture or vegetable farming is the science of growing vegetables. Vegetable farming is classified into
1.) Kitchen or nutritional gardening:
Kitchen gardening is the growing of vegetables in a small scale at household. For example: beans, cabbage, lady’s finger, tomato, carrots, brinjal, spinach etc.
2.) Commercial gardening:
It is the production of vegetables in large scale which are to be sold in market.
3.) Vegetable forcing:
It is the method of growing vegetables in buildings, green houses, cold farms or under other artificial growing conditions. It is the most intensive type of vegetable growing.
For example: Cabbage, tomato, brinjal etc.
3) Mention any two mushroom preservation methods.
Ans: Discolouration, weight and flavor loss are the main problems during harvesting of mushrooms.
The following methods are used to preserve the mushrooms.
4.) Vacuum cooling
5.) Gamma radiation and storing at 15°C.
4) Enumerate the advantages of vermicompost over chemical fertiliser.
- The vermicompost is dark brown in colour and similar to farmyard manure in colour and appearance.
- The advantages of vermicompost over chemical fertilizers are as follows.
- It is the rich source of nutrients which are essential for the plant growth and it makes soil fertile.
- It improves the water holding capacity and helps to prevent the soil erosion.
- It contains valuable vitamins, enzymes, growth regulator substances for increasing growth, vigour and yield of plants.
- It enhances decomposition of organic matter in the soil.
- Vermicompost is free from pathogen and toxic elements.
- Vermicompost is rich in beneficial microflora.
5) What are the species of earthworm used for vermiculture?
Ans: Vermiculture involves the artificial rearing or cultivation of earthworms and using them for the production of compost from natural organic waste. Earthworm species used for vermiculture are Perionyx excavatus (Indian blueworm), Eisenia fetida (Red worms), Eudrilus eugeniae (African night crawler).
6) List the medicinal importance of honey.
Ans: Honey is a sweet, viscous, edible natural food product. It contains amino Acids, B complex vitamins, ascorbic acid and minerals. Formic acid is a preservative in honey. Invertase is an enzyme present in honey.
The medicinal uses of honey are as follows.
- It has antiseptic and antibacterial property and it is a blood purifier.
- It helps in building up of haemoglobin content in the blood.
- It is used in Ayurvedic and Unani system of medicines.
- It prevents cold, cough and fever relieves soar throat.
- It is a remedy for ulcers of tougue, stomach and intestine.
- It enhances digestion and appetite.
VII. Answer in detail.
1) Enumerate the advantage of hydroponics.
Ans: Hydroponics is the method of growing plants without soil, using mineral nutrients solutions in water. It was demonstrated by German Botanist Julius Von Sachs in 1980. Hydroponics is successfully employed for the commercial production of seedless cucumber and tomato.
The advantages of hydroponics are as follows.
- Hydroponics requires far less space than plants grown in soil.
- It requires less labor.
- Produces high crop yields.
- Produces higher quality food.
- Conservation of water and nutrients.
- Controlled plant growth.
- In desert and Arctic regions hydroponics can be an effective alternative method.
2) Define Mushroom culture. Explain the mushroom cultivation methods.
Ans: Mushroom cultivation is the technology of growing mushrooms using plant, animal and industrial waste. Mushroom is a fungi belonging to basidiomycetes. It is rich in proteins, fibres and vitamins and minerals. There are more than 300 types of mushrooms. For example: button mushrooms, oyster mushrooms, paddy straw mushrooms. The cultivation takes one to three months. The major stages involved in mushroom cultivation are as explained below.
Compost is prepared by mixing paddy straw with number of organic materials like cow dung and inorganic fertilizers. It is kept at about 50°C for one week.
Spawn is the mushroom seed. It is prepared by the growing fungal mycelium in grains under sterile conditions. Spawn is sown on compost.
Compost is covered with the thin layer of soil. It gives support to the growing mushrooms, provides humidity and helps to regulate the temperature.
Mycelium starts to form little bud, which will develop into mushroom. Those little white buds are called as pins.
Mushroom grow better in 15°C -23°C. They grow 3 cm in a week which is the normal size of harvesting. In the third week the first flush mushrooms can be harvested.
3) What are the sources of organic resources for vermicomposting?
Ans: Vermicompost is the excreta which is a fine, granular organic matter formed by the decomposition of organic materials by the earthworms. It is an ideal fertilizer for the soil. Biologically degradable organic waste are used as potential organic resources for vermicomposting and they are as given below. Agricultural wastes like crop residue, vegetables waste, sugarcane cash.
Crop residue like rice straw, tea waste, cereal and pulse residues, rice husk, tobacco waste, coir waste. Leaf litter Fruit and vegetables waste Animal wastes like cow dung, poultry droppings, and pig slurry, goat and sheep droppings. Biogas slurry.
4) Give an account of different types of fish ponds used for rearing fishes.
Ans: Fish farm requires different types of ponds for the various developmental stages of fish growth which are given as below.
1.) Breeding pond:
Healthy and mature male and female fishes are collected and introduced in this pond for breeding. The eggs released by the female are fertilized by the sperm and fertilized eggs float in water as frothy mass.
2.) Hatching pits:
The fertilized eggs are transferred to hatching pits or hatching hapas for hatching.
3.) Nursery ponds:
The hatchings are transferred from hatching pits after 2-7 days. The hatching grow into fry and are cultured in these ponds for about 60 days with proper feeding till they reach 2-2.5 cm in length.
4.) Rearing ponds:
Rearing ponds are used to culture the fry. The fish fry are transferred from nursery pond to tearing ponds and are maintained for about three months till they reach 10-15 cm in length. In these rearing ponds the fry develops into fingerlings.
5.) Stocking ponds:
The stocking pond is also called as culture pond or production pond. These ponds are used to rear fingerlings up to the marketable size.
5) Classify the different breeds of the cattle with suitable examples.
Ans: The Indian cattle includes cows and buffaloes. They are domesticated for milk, meat, leather and transportation. They belongs to two different species, Bos indicus (Indian cows and bulls) and Bos bubalis (buffaloes). These cattle animals are reared for milk and farm labour. They are classified into three types, dairy breeds, draught or draft breeds and dual purpose breeds.
1.) Dairy breeds:
Dairy animals are domesticated for obtaining milk. The cows i.e. milk producing females are high milk yielders. The dairy breeds are indigenous breeds and exotic breeds.
2) Exotic breeds:
Exotic breeds are imported from foreign countries.
They include Jersey, Brown Swiss and Holstein-Friesian etc.
These foreign breeds are selected for long lactation period.
3) Indigenous breeds:
Indigenous breeds are native of India.
They include Sahiwal, Red Sindhi, Deoni and Gir.
Milk production depends on the duration of the lactation period. These local breed animals shows excellent resistant to diseases.
4) Draught or draft breeds:
They are used for agricultural work, such as tilling, irrigation and carting. These includes Amritmahal, Kangayam, Umblachery, Malvi, Siri and Hallikar breeds. Bullocks are good draft animals while the cows are poor milk yielders.
5) Dual purpose breeds:
The cows of these breeds provides milk and the bulls are useful for farm work. In India these breeds are favoured by farmers. They includes Haryana, Ongole, Kankrej and Tharparkar.
VIII. Higher Order Thinking Skills.
1) Biomanuring plays an important role in agriculture. Justify
Ans: Organic manures predominantly derived from plant debris, animal faces and microbes. They makes the soil fertile by adding nutrients like nitrogen. The few of organic manures are animal manure which includes farmyard manure which contains 0.5% nitrogen, 0.2% available phosphate and 0.5% available potash. Sheep and goat manure which contains 3% nitrogen, 1% phosphorus pentoxide and 2% potassium oxide. Also, compost is a soil conditioner as well as a fertilizer which is rich in nutrients. Green manure improves soil structure, increases water holding capacity and decreases soil loss by erosion. It also helps in reclamation of alkaline soils and reduce weed proliferation. Thus biomanuring plays a very important role in agriculture.
2) Each bee hive consists of hexagonal cells. Name the material in which the cell is formed and mention the significance of the hexagonal cells.
Ans: The comb of the bees is mainly formed by the secretion of wax glands present in the abdomen of the worker bee. A comb is a vertical sheet of wax with double layer of hexagonal cells. Thus hexagonal cells are formed in wax sheet. The hexagonal shape of the cells allows to hold the queen bee’s eggs and also stores pollen and honey for which the worker bees bring to the hive.
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