Text Book Back Questions and Answers - Chapter 12 Trends in Economic Zoology 11th Biology Zoology Guide Samacheer Kalvi Solutions - SaraNextGen [2024-2025]

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On April 24, 2024, 11:35 AM

Trends in Economic Zoology
Text Book Back Questions and Answers
Textbook Evaluation Solved
Choose The Correct Answer
Question 1.
Which one of the following is not related to vermiculture?
(i) Maintains soil fertility
(ii) Breakdown of inorganic matter
(iii) Gives porosity, aeration and moisture holding capacity
(iv) Degradation of non biodegradable solid waste
(a) (i) and (ii) is correct
(b) (iii) and (iv) is correct
(c) (ii) and (iv) is not correct
(d) (i) and (iii) is not correct
Answer:
(c) (ii) and (iv) is not correct
Question 2.
Which one of the following is not an endemic species of earthworm?
(a) Perionyx
(b) Lampito
(c) Eudrillus
(d) Octochaetona
Answer:
(c) Eudrillus
Question 3.
Match the following
(1) Bombyx mori - a) Champa - (1) Muga
(2) Antheraea assamensis - b) Mulberry - (II) Eri
(3) Antheraea mylitta - c) Arjun - (III)Tassar
(4) Attacus ricini - d) Castor - (IV) Mulberry Select the correct one.
(a) $1-\mathrm{b}-\mathrm{IV}$

(b) $2-a-1$
(c) $3-c-$ III
(d) $4-d-I I$
Answer:
(c) $3-c-$ III
Question 4.
Silk is obtained from
(a) Laccifer lacca
(b) Nosema bombycis
(c) Attacus ricini
(d) Attacus mylitta
Answer:
(c) Attacus ricini
Question 5.
Assertion: Nuptial flight is a unique flight taken by the queen bee followed by several drones.
Reason: The queen bee produces a chemical substance called pheromone. The drones in that area are attracted to the pheromone and then mating takes place.
(a) Assertion and reason is correct but not related
(b) Assertion and reason is incorrect but related
(c) Assertion and reason is correct but related
(d) Assertion and reason is incorrect but not related
Answer:
(c) Assertion and reason is correct but related
Question 6.
Rearing of honey bee is called
(a) Sericulture
(b) Lac culture
(c) Vermiculture
(d) Apiculture
Answer:
(d) Apiculture

Question 7.
Which of the statement regarding Lac insect is TRUE?
(a) A microscopic, resinous crawling scale insect
(b) Inserts its proboscis into plant tissue suck juices and grows
(c) Secretes lac from the hind end of body
(d) The male lac insect is responsible for large scale production of lac Answer:
(c) Secretes lac from the hind end of body
Question 8.
Aquaponics is a technique which is
(a) A combination of aquaculture and fish culture
(b) A combination of aquaculture and hydroponics
(c) A combination of vermiculture and hydroponics
(d) A combination of aquaculture and prawn culture
Answer:
(b) A combination of aquaculture and hydroponics
Question 9.
Prawn belongs to the class
(a) Crustacea
(b) Annelida
(c) Coelenterata
(d) Echinodermata
Answer:
(a) Crustacea
Question 10.
Pearl oyster belongs to the Class
(a) Gastropoda
(b) Cephalopoda
(c) Scaphapoda
(d) Pelecypoda
Answer:
(d) Pelecypoda

Question 11.
Inland fisheries are
(a) Deep sea fishing
(b) Capturing fishes from sea coast
(c) Raising and capturing fishes in fresh water
(d) Oil extraction from fish
Answer:
(c) Raising and capturing fishes in fresh water
Question 12.
Induced breeding technique is used in
(a) Marine fishery
(b) Capture fishery
(c) Culture fishery
(d) Inland fishery
Answer:
(b) Capture fishery
Question 13.
Isinglass is used in
(a) Preparation
(b) Clearing of wines
(c) Distillation of wines
(d) Preservation of wines
Answer:
(b) Clearing of wines
Question 14.
Animal husbandry is the science of rearing, feeding and caring, breeding and disease control of animals. It ensures supply of proper nutrition to our growing population through activities like increased production and improvement of animal products like milk, eggs, meat, honey, etc.
(a) Poultry production depends upon the photoperiod. Discuss.
(b) Polyculture of fishes is of great importance.
Answer:

(a) Light is an important aspect in the poultry production. Light stimulates the secretion of $\mathrm{FSH}$ and $\mathrm{LH}$. The wavelength between 400 and $700 \mathrm{~nm}$ is required. The decrease in the photoperiod will affect the egg production.
(b) A few selected fishes belonging to different species are stocked together in proper proportion in a pond. This mixed forming is termed as composite fish farming or polyculture. It is of great importance because
1. All available riches are fully utilized
2. Compatible species do not harm each other
3. There is no competition among different species
Question 15.
Assertion: The best quality of pearl is known as lingha pearl and obtained from marine oysters.
Reason: Nacre is secreted continuously by the epithelial layer of the mantle and deposited around the foreign particle.
(a) Assertion is true, Reason is false
(b) Assertion and Reason are false
(c) Assertion is false But Reason is true
(d) Assertion and Reason are true
Answer:
(c) Assertion is false But Reason is true
Question 16.
Choose the correctly matched pair.
(a) Egg layers - Brahma
(b) Broiler types - Leghorn
(c) Dual purpose - White Plymouth rock
(d) Ornamental breeds - Silkie
Answer:
(d) Ornamental breeds - Silkie

Question 17.
Write the advantages of vermicomposting?
Answer:
1. Vermicomposting provides excellent organic manure for sustainable agro-practices.
2. Marketing of vermicompost can provide a supplementary income.
3. Vermicompost is rich in essential plant nutrients.
4. It improves soil structure, texture, aeration, and water holding capacity and prevents soil erosion.
5. It is rich in nutrients and an eco-friendly amendment to soil for farming and terrace gardening,
6. It enhances seed germination and ensures good plant growth.
Question 18.
Name the three castes in a honey bee colony?
Answer:
The Queen, Drones and Workers.
Question 19.
Name the following?
1. The largest bee in the colony:
2. The kind of flight which the new virgin queen takes along with the drones out of the hive:
Answer:
1. The queen.
2. Nuptial flight.
Question 20.
What are the main duties of a worker bee?
Answer:
Each worker has to perform different types of work in her life time. During the first half of her life, she becomes a nurse bee attending to indoor duties such as secretion of royal jelly, prepares bee- bread to feed the larvae, feeds the queen, takes care of the queen and drones, secretes bees wax, builds combs, cleans and fans the bee hive. Then she becomes a soldier and guards the bee hive. In the second half her life lasting for three weeks, she searches and gathers the pollen, nectar, propolis and water.

Question 21.
What happens to the drones after mating flight?
Answer:
They die after copulation.
Question 22.
Give the economic importance of Silkworm?
Answer:
1. Rearing of silkworm on a commercial scale is called sericulture.
2. It is an agro-based industry comprising of
1. - Cultivation of food plants for the silkworms.
2. - Rearing of silkworms.
3. - Reeling and spinning of silk.
3. Silk fibres are utilized in preparing silk clothes.
4. Silk is used in industries and for military purposes.
5. Silk is used in the manufacture of fishing fibres, parachutes, cartridge bags, insulation coils for telephone, wireless receivers, tyres of racing cars, filter fibres, in medical dressings and as suture materials.
Question 23.
What are the Nutritive values of fishes?
Answer:
Economic importance of fish:-
Fishes form a rich source of protein food and provide a good staple food to tide over the nutritional needs of man. Fish species such as sardines, mackerel, tuna, herrings have high amino acids concentration particularly histidine which is responsible for the meaty flavor of the flesh. It is rich in fat such as omega 3 fatty acids. Minerals such as calcium, magnesium, phosphorus, potassium, iron, manganese, iodine and copper.

Some of the fish by-products are: Fish oil is the most important fish byproduct. It is derived from fish liver and from the fish body.
Fish liver oil is derived from the liver which is rich in vitamin $A$ and $D$, whereas fish body oil has high content of iodine, not suitable for human consumption, but is used in the manufacture of laundry soaps, paints and cosmetics. Fish meal is prepared from fish waste after extracting oil from the fish.

The dried wastes are used to prepare food for pig, poultry and cattle. The wastes obtained during the preparation of fish meal are widely used as manure.
Isinglass is a high-grade collagen produced from dried air bladder or swim bladder of certain fishes viz. catfish and carps. The processed bladder which is dissolved in hot water forms a gelatin having adhesive property. It is primarily used for clarification of wine, beer and vinegar.
Question 24.
Give the economic importance of prawn fishery?
Answer:
The flesh of prawn is palatable and rich in glycogen, protein with low fat content.
Question 25.
Give the economic importance of lac insect?

Answer:
Economic importance of Lac:-
1. Lac is largely used as a sealing wax and adhesive for optical instruments. It is used in electric industry, as it is a good insulator.
2. It is used in preparations of shoe and leather polishes and as a protective coating of wood.
3. It is used in laminating paper board, photographs, engraved materials and plastic moulded articles.
4. Used as a filling material for gold ornaments.
Question 26.
List any three common uses of shellac?
Answer:
1. Shellac with denatured alcohol is used to remove dust on the walls.
2. Coating of metals with shellac prevents rusting.
3. Shellac coating on citrus fruits increases their shelf life.
Question 27.
Name any two trees on which lac insect grows?
Answer:
Acacia catechu, Acacia nilotica.
Question 28.
What is seed lac?
Answer:
Lac cut from the host plant is called 'stick lac'. The lac present on the twig is scraped and collected. After grinding, the unnecessary materials like dusts and fine particles are removed. The resultant lac is called 'seed lac'.
Question 29.
Define cross breeding?
Answer:
Breeding between a superior male of one breed with a superior female of another breed is known as cross breeding.

Question 30.
What are the advantages of artificial insemination?
Answer:
Advantages of artificial insemination:
1. It increases the rate of conception
2. It avoids genital diseases
3. Semen can be collected from injured bulls which have desirable traits
4. Superior animals located apart can be bred successfully
Question 31.
Discuss the various techniques adopted in cattle breeding?
Answer:
There are two methods of animal breeding, namely inbreeding and outbreeding.
1. Inbreeding:
Breeding between animals of the same breed for 4-6 generations is called inbreeding.
2. Outbreeding:
The breeding between unrelated animals is called outbreeding. It is done in three ways;
- Out crossing: It is the breeding between unrelated animals of the same breed but having no common ancestry. The offspring of such a cross is called outcross.
- Cross breeding: Breeding between a superior male of one breed with a superior female of another breed. The cross bred progeny has superior traits (hybrid vigour or heterosis).
- Interspecific hybridization: In this method of breeding mating is between male and female of two different species.
Question 32.
Mention the advantages of MOET?
Answer:

Multiple Ovulation Embryo Transfer Technology (MOET) is a method of propagation of animals with desirable traits. This technology is used to produce high milk yielding females and high quality meat yielding bulls in a short time.
Question 33.
Write the peculiar characters of duck?
Answer:
Peculiarity of ducks:
The ducks body is fully covered with oily feathers. They have a layer of fat under their skin which prevents it from getting wet. They lay eggs at night or in the morning. The ducks feed on rice bran, kitchen wastes, waste fish and snails.
In - Questions Solved
Question 1.
My vennicompost manufacturing unit is plagued by a number of red ants. Are there any bio-friendly measures to tackle the menace as I do not want to use any chemicals?
Answer:
There are few bio-friendly measures to tackle the menace. For eg. Sprinkling of cinnamon powder or cloves can repel ants.
Question 2.
India has the distinction of producing all the four types of silk i.e.
(a) Mulberry silk (9-1.7\%)
(b) Tasar silk (1.4\%)
(c) Eri silk (6.4\%) and
(d) Muga silk ( $0.5 \%)$ which are produced by different species of silkworms. Name the species that produces large amount and least amount of silk in India?
Answer:
Bombyx mori produces large amount of silk in India and Antheraea assamensis produces least amount of silk in India.

Question 3.
(a) Growing fish or other aquatic animals and plants together in an integrated system. The fish wastes provides nutrients for the plants and the plants filter the water. Additionally bacteria break down by-products such as ammonia?
(b) Growing plants in a nutrient solution instead of soil. Fish kept in the water provide the required nutrients. Write the appropriate scientific terms for above (a) and (b) and differentiate between them?
Answer:
(a) Aquaponics
(b) Hydroponics

Question 4.
Why are fish so efficient at converting feed to flesh?
Answer:
Fish is more efficient in converting a greater proportion of feed they receive into flesh because as fish live in water they expend less energy to maintain internal body temperature and also by excreting a more simple form of urine (ammonia).