Category: 12th Zoology

Computed Tomography CT

Computed Tomography (CT)(OR) Computerized axial tomography (CAT).

The imaging technology or machine vision has revolutionized the
medical world. It enables the doctors to watch vital organs, identify
blockages and growths and diagnose signs of diseases without doing
surgery.

Computed tomography scan or (CT) scan :

Computed Tomography (CT) or “CAT scanning” combines the use
of a digital computer together with a rotating X-ray device to create detailed
cross sectional images or “slices’ of the different organs.

Advantages of Computed Tomography CT over other imaging techniques

Among the various imaging techniques CT has the unique ability to
image a combination of soft tissue, bone, and blood vessels. For example,
conventional x-ray image of the head can only show the dense bone
structures of the skull. X-ray angiography of the head depicts only the head
and neck and not the soft brain-tissue. Magnetic resonance (MR) imaging
does an excellent job of showing soft tissue and blood vessels, but MRdoes
not give as much details of bony structures such as the skull.CT images of
the head allow physicians to see soft-tissues, anatomic structures like the
brain’s ventricles, of grey and white matter. CT can provide detailed cross
sectional images and diagnostc information for nearly every part of
the body.

Uses of CT Computed Tomography

1. CT is an invaluable tool in the cancer diagnosis process and is often the
preferred method for diagnosing lung, liver and pancreas cancer.
2. CT imaging and CT angiography are finding a greater role in the detection,
diagnosis and treatment of heart disease, acute stroke and vascular diseases,
which can lead to stroke, gangrene or kidney failure.
3. CT can be used to measure bone mineral density for the detection of
osteoporosis.

4. CT has excellent application in trauma cases and other internal bleeding in
patients.
5.CT is used extensively for diagnosing problems of the inner ears and
sinuses. The anatomy of the inner ear and sinuses is made up of delicate soft
tissue structures and very fine bones. CT is excellent for imaging tumors or
polyps in the sinuses and disease that cause degeneration of the small bones
in the inner ear.
6. CT has been the basis for interventional work like CT guided biopsy and
minimally invasive therapy. CT images are also used as basis for planning
radiotherapy cancer treatment. CT is also often used to follow the course of
cancer treatment to determine how the tumor is responding to treatment.

Unit 7. THEORIES OF EVOLUTION Topic List Zoology

12th Zoology

ECG Electrocardiogram

The electrocardiogram (ECG) is a record of the electric potential
changes that occur in the heart during the cardiac cycle. It is recorded from
the surface of the body. The instrument used to record the ECG is called
Electrocardiogram. The waves of the ECG are due to depolarization and not
due to contraction of the heart. This wave of depolarization occurs first
before the contraction of the cardiac muscle begins.

The electrical activity of the heart was first recorded by Waller in
1887 with a capillary electrometer. But the work of Einthoven who recorded
the ECG with a strong galvanometer only lead to the development of modern
electrocardiography. Einthovan was awarded Nobel Prize in 1924.
A normal ECG is composed of five waves designated from left to
right with the letters P,Q,R,S and T. P,R and T are normally upward or
positive waves while Q and S are downward or negative waves.
ECG-’PQRST’ wave

When the cardiac impulse (originating in sinus node which is the
primary pace maker) passes through the heart, electrical currents spread in
the tissues surrounding the heart. A small amount of this current spreads to
the surface of the body. If electrodes are placed on the skin on opposite
sides of the heart, electric potentials generated by these currents can be
recorded. This recording is known as electrocardiogram (ECGorEKG).
P.Wave: It occurs in the auricles. It is an atrial wave. It is due to the
spread of depolarisation in the atria (auricles). Its duration is 0.1 second and
it occurs just before the atrial systole. Its amplitude is about 0.1 to 0.3 mv.The
cardiac impulse reaches the sinu-auricular node at about the summit of the
Pwave. The P wave is a guide to the activity of atria.
Q,R, and S Waves

After the completion of P wave, the isoelectric interval occurs.
Following this, QR and S waves begin. Q wave is a small negative
downward deflection. It is mostly indistinct. It represents atrial septal
depolarization. R wave is a prominent positive wave and S wave is a small
negative wave. R and S are due to depolarization of the ventricular muscle.
The duration of the QRS complex is about 0.08 second and usually does not
exceed 0.1second. The average amplitude to R wave is about 1 mv. Lot of
diagnostic information can be gained from alteration in the QRS complex.
T wave

Following S wave there is an isoelectric interval. T wave begins after
that. It is due to ventricular repolarization. It is a broad wave. Its average
duration is about 0.27 second and amplitude 0.15 to 0.5 mv.

Unit 7. THEORIES OF EVOLUTION Topic List Zoology

12th Zoology

Urine Sugar analysis

The examination of urine (pyhsical, chemical and microscopic) is called
Urinalysis. It provides a valuable picture of the general health pattern of a
patient. Urinalysis is usually done to
(i) find out the state of the kidneys and the urinary tract, and
(ii) gather information about metabolic and systemic abnormalities.
To diagnose metabolic and systemic disorders such as diabetes and
jaundice, tests for glucose, ketone bodies, bilirubin and urobilinogen should
be carried out.

Collection and preservation of Urine

Urine is mainly composed of 95% water, and the rest being made of
urea, uric acid, creatinine, sodium, potassium, chloride, calcium, phosphates
etc. It must be collected in a clean, dry container and examined as soon as
possible. For testing glucose, urine collected 2 to 3 hours after food is
suitable.

Sugar Analysis

Sugars are generally known as reducing substances because they can
reduce a heavy metal, such as copper, from a higher to a lower oxidation
state for example, the reduction of blue cupric sulphate to red cuprous oxide.
Glucose, lactose, fructose, galactoese, pentoses, sucrose etc., are the
reducing substances found in urine. Even though there are many reducing
substances in the urine, estimation of glucose is important, as it indicates the
hyperglycemic condition. (Urine Sugar analysis)

Significance of Glucose

Glucose is present in trace amonts in normal urine. In the kidneys,
glucose is filtered by the glomeruli and reabsorbed by the tubules. Above a
certain limit the tubules cannot reabsorb all the glucose. The surplus glucose
appears in urine and this condition is known as glycosuria. When
glycosuria is detected and hyperglycemia (excess glucose) is estalished, the
chronic disorder, diabetes mellitus is indicated. In this condition as much
as 280 milli moles/ L of glucose can be found in urine. It indicates
disturbances in carbohydrate, lipid and protein metabolism.

Urine glucose is tested both qualitatively and quantitatively. Benedicts
test is the qualitative test to indicate the presence or absence of sugars.
Different types of quantitative tests, each of them based on some principle
are also employed to quantitate the urine sugar content. Some of them are
Bendicts reagent method, glucose oxidase method ,o- toluidene method etc.
Thin layer chromatography is considered a superior method for
identification of urine sugars. Recently, digital glucometer is in usage for
instantaneous determination of blood glucose levels. (Urine Sugar analysis)

Unit 7. THEORIES OF EVOLUTION Topic List Zoology

12th Zoology

Haemocytometer

The counting of blood cells after proper dilution is known as
haemocytometry and the instrument used to count the blood cells is called
haemocytometer. Using haemocytometry method, red cells, platelets and eosinophils are often counted. Now-a-days it is also used for counting cells
of bacteria, yeast, or algae.

Haemocytometer – instruments description

A haemocytometer consists of a counting chamber, a coverglass for
the counting chamber and diluting pipettes. Many types of counting
chambers are available. Improved Neubauer and Fauchs Rosenthal are the
two most commonly used counting chambers in laboratories.
RBCs and WBCs in blood cannot be counted as such. The blood
has to be diluted in specific isotonic solutions. RBC, diluting fluid is called
Hayem’s solution. For WBC counting Turk’s solution or Toisson solution
can be used.

The total number of cells is expressed per mm3. The isotonic diluting
fluid keeps up the cells intact. In WBC counting, the solution will lyse the
red blood cells and the remaining nucleated WBCs are counted. Venous
blood is used in blood cells counting.

Normal Range of RBCs in human is as follows

Men : 4.5 – 5.9 million/mm3
Women : 4.1 – 5.1 million/mm3
At birth : 4.0 – 5.6 million/mm3
Normal Range of WBCs in human is as follows :
Adults : 4,500 – 11,000/mm3
Neonates : 10,000 – 25,000/mm3

Clinical significance :

1. Decrease in the number of circulating erythrocytes indicates anaemia.
2. An increased number of erythrocytes indicates the possibility of
polycythemia.
3. An increase in WBC count for a transient period indicates bacterial
infection.
4. Progressive increase in abnormal WBC count indicates the possibility of
leukemia.

Unit 7. THEORIES OF EVOLUTION Topic List Zoology

12th Zoology

Sphygmomanometer

A sphygmomanometer is an instrument used to measure blood
pressure. The word is derived from the Greek sphygmus (pulse) plus the
scientific (physical) term manometer.

Arterial blood pressure is the force of pressure, which the blood is
exerting on the walls of the blood vessels in which it flows. The blood
pressure in the artery varies during the cardiac cycle. The cardiac cycle is
defined as the cycle of events that take place during one systole and diastole
of the heart. Systole refers to contraction and diastole the relaxation. During
ventricular systole, when the left ventricle is forcing blood into the aorta the
pressure rises to a peak which is referred to as systolic pressure. During
diastole the pressure falls and the lowest value reached is referred to as
diastolic pressure.

The blood pressure depends partly on the force and volume of blood
pumped by the heart and partly on the contraction of the muscles in the walls of the arterioles. Blood pressure changes during physical exercise, during
anxiety and emotion and in sleep etc. However a prolonged or constant
elevation of blood pressure, a condition known as hypertension can increase
a person’s risk for heart attack, stroke, heart and kidney failure and other
health problems. It is always suitable to measure blood pressure when a
person is in a relaxed and in resting condition.

The normal blood pressure value is 120/80mm Hg, in which ‘120’
denotes the systolic pressure and 80 the diastolic pressure.
There are two types of sphygmomanometer viz., Monometric type
and 2. Digital (modern) type.

Uses

1. Sphygmomanometer helps to estimate the state of blood circulation and
the working of heart.
2. Sphygmomanometer helps to diagnose pathological conditions such as
hypertension (increased BP) and hypotension (reduction in BP).

Unit 7. THEORIES OF EVOLUTION Topic List Zoology

12th Zoology

Medical Lab Techniques – Stethoscope

Post author By Mr. Padeepz
Post date November 30, 2018
No Comments on Medical Lab Techniques – Stethoscope

Medical Lab Techniques

In medical therapeutics both diagnosis and treatment are the two
important vital aspects. Diagnosis involves identifying or determining the
nature of disease while treatment involves the curative aspects in order to
eliminate the disease causing agent. The clinical laboratory tests help a
physician in correct diagnosis and treatment.

Stethoscope

A stethoscope is used to hear the heart beat sounds, sound due to
inhalation and exhalation of air in the lungs and the respiratory pathways and also the stomach movement. It is a very useful diagnostic tool to help localize
problems and to diagnose disease.

Stethoscopes are also used along with the sphygmomanometer. The first usable binaural stethoscope was invented in 1855. The modern electronic stethoscopes are high precisioned instruments.

These can be used to hear a patient’s heart and lung clearly even in high noisy environments and even through layers of clothing. The electronic stethoscopes also make it possible to hear the foetal sounds in mother’s womb.

Uses

1. Stethoscope helps to find normal (lub-dub) versus abnormal heart sounds
(heart murmurs) and also to diagnose valve functions.
2. Stethoscopes can indicate fluid in lungs in case of pneumonia and
pulmonary edema. It can diagnose airway diseases like bronchitis and
pleuritis.
3. Stethoscopes are also used to compare the movements in the normal
versus overactive or underactive intestinal tract.

Unit 7. THEORIES OF EVOLUTION Topic List Zoology

12th Zoology

Edible Fishes Of Tamilnadu

Post author By Padeepz
Post date November 29, 2018
No Comments on Edible Fishes Of Tamilnadu

Edible Fishes Of Tamilnadu

I. Fresh Water Fishes

Among the freshwater fishes, carps belonging to the order
Cypriniformes form significant components of reservoir, riverine and culture
fisheries. They have no teeth in any part of their mouths, however
pharyngeal teeth may be present.

i. Indian Major Carps (‘Kendai’ meen)

a) Catla catla (catla) :

Catla has a deep body with prominent head, large
upturned mouth, non-fringed lips, devoid of barbels and a broad dorsal fin
with 14-16 branched rays are the identifying features. It feeds on
zooplankton of the pond surface using large gill rakers; however, young ones
(15-20 mm) feed on zooplankton and phytoplankton. It grows to a maximum size of 1.8 m (45 kg). It is a fast growing species among the Indian
major carps. First year growth is 35-45 cm and about 1.5 – 2.0 kg. It
matures in the second year. (Edible Fishes)

b) Labeo rohita (Rohu) :

Of all the carps, this is considered as the tastiest
fish. It has a small and pointed head, terminal small mouth with fringed lower
lip. A dorsal fin with 12-13 branched rays and full reddish scales are its
identifying features. It is a column feeder on phytoplankton, plant debris or
decaying debris of aquatic plants; however, the young feed on zooplankton.
The maximum size attained is 1m. It is fairly fast growing species and first
year growth is 35 – 40 cm and 900 g.

c. Cirrhina mrigala (Mrigal) :

A linear body small head with blunt snout, subterminal mouth with thin non-fringed lips, dorsal fin with 12-13 branched rays and a bright silvery body having golden tinge are its identifying features.

It is a bottom feeder on decaying organic and vegetable debris; however, its
young feed on zooplankton. The maximum size attained is 0.9 m. Its growth
in the first year is about 30 cm (700 g). (Edible Fishes)

(ii) Catfishes (Order: Siluriformes-‘Keluthi’)

The catfish are air-breathing, or live-fishes as they are capable of
directly breathing atmospheric air. They can live for a long time without
water and can therefore be transported live and in fresh condition over long
distances. The body is without scales and each of the upper and lower jaws
possesses two pairs of long barbels in each. The mouth is non-protractile
having jaws with teeth. Majority of the catfish are predatory and
cannibalistic, feeding on all pond animals including fish fry. (Edible Fishes)

(iii) Murrels or Snakeheads (Order : Channiformes-‘Viral’ meen)

These fish are also air-breathing and have a good demand.
Elongated and cylindrical body, depressed head, large and protractile mouth
are its identifying features. Murrels are suitable for culture in irrigation wells
and shallow swamps. (Edible Fishes)

a) Channa marulius (Giant snakehead) : Dorsal and anal fins of this species
are long and without spines. It reaches a maximum size of 1.2 m. It is suitable
for culture in ponds along with tilapia, the young ones of which serve as food
source to this species.

b) C.striatus (Striped snake-head or Common murrel) : Stripes are present
on its body. Attains a maximum size of 90cm. (Edible Fishes)

(iv) Tilapia (Order : Perciformes)

a) Oreochromis mossambicus (Tilapia -‘Jilabi’ kendai) : An exotic fish
introduced in India from East Coast of Africa in 1952. It is characterized by
an anterior spinous dorsal fin and posterior soft dorsal fin. Maturity occurs
even in two months old individuals. It breeds nearly eight times in a year.
Female keeps the fertilized eggs guarded in its mouth.

II. Brackish water Fishes

Brackish water fishes spend most of its life in river mouths
(estuaries) back waters, mangrove swamps and coastal lagoons. These are Chanos Chanos (Milk fish), Grey mullets (‘Madavai’), Pearl spots
(‘Kari’meen), Seabass (‘Koduva’), The Seabreams. (Edible Fishes)

III. Marine Fishes

Marine edible fishes of Tamilnadu coast include both cartilaginous
and bony fishes.

Elasmobranchiata

Cartilagenous fishes are the sharks and skates.
Bony Fishes are

i) Pomfrets (‘Vavva’): ii) Indian Mackeral (‘Kanangeluthi’) : iii) Seer fish
(‘Vanjiram’ or ‘Neimeen’): iv) Carangids (‘Para’ meen):(v) Ribbon fishes:
(vi) Catfishes (‘Keluthi’): (vii) Flat fishes (‘Naakku meen’):(viii) Sardines
(‘Maththi meen’): (Edible Fishes)

Unit 7. THEORIES OF EVOLUTION Topic List Zoology

12th Zoology

Fish Pond

A successful aquaculture practice with a good harvesting is usually
due to proper construction preparation and maintenance of the fish pond.

Types of fish ponds

Within the fish farming pond system there can be different pond
components, namely nursery, rearing, production, segregation and breeding
or spawning ponds. The area percentage of these ponds in a fish-farming
complex can be:
Nursery pond – 3%
Rearing pond – 11%
Production pond – 60%
Segregation pond – 1%
Breeding pond – 25%
Nursery ponds are shallow, while the others are moderately deep. In
larger production ponds, water can be maintained at a depth of 2 and 3
metres. A fencing around the fish farm, may be constructed for protection.

Preparation of pond
Before the culturing of fish, the pond should be conditioned.

1. Conditioning

A layer of lime (calcium hydroxide) is spread over the bottom, for
two weeks. It removes the acidity of the soil, facilitates desirable
geochemical cycles and kills unwanted soil organisms.
Water may be let in slowly after two weeks and filled to the desired
depth. The quality parameters such as temperature, oxygen content, pH, turbidity, hardness, alkalinity and plankton growth should be checked for
their optimal levels, before stocking the fish.

2. Manuring

After 15 days of liming, the fertilization is to be done in order to
develop the fish food organisms (phytoplankton and the zooplankton: macro
and micro). Manure may be of organic or chemical nature. Organic manure
may be urine or sewage rich in nitrogenous matter,cow dung, pig dung,
poultry manure and plant manure such as green manure, compost, oil cake
etc. If the organic carbon is less, cow dung for the stocking pond is applied
at the rate of 2-3 tonnes / ha. Poultry manure at the rate of 5000 kg / ha is
known to enhance zooplankton induction. Use of chemical fertilizers should
vary according to the concentration of phosphorus and nitrogen in the soil.
The standard combination of NPK as 18 : 10 : 4 is generally
recommended for freshwater ponds. For a production pond of medium
fertile soil; urea at the rate of 200 kg / ha / yr or ammonium sulphate at the
rate of 450 kg / ha / yr may be applied in split up dozes, alternating with
organic manure.
Management of fish farm
Feed and water quality are the two major factors governing the
productivity of the fish culture pond. Besides, seed quality, stocking and other
management measures also determine the extent of fish production.
Water quality involves the regulation of
Temperature at 25-33o
C, dissolved oxygen, pH (6.5 – 9.0 ),
hardness, alkalinity, turbidity and plankton culture etc..

Feeding

Apart form natural food, most cultured species take artificial feeds.
In general artificial feed should contain 30-40% protein, 5-10% fat,
50-60% carbohydrate, less than 5% cellulose, 10% water, vitamins and
minerals. Animal and vegetable ingredients can be used in formulating feed
pellets. Fishmeal, prawn meal, soybean meal, silkworm pupa, wheat,
tapioca, slaughter house wastes, rice bran, aquatic weeds, oilcakes etc are good feed ingredients. Usually Indian farmers give rice bran and oil cakes in
powder form to major carps.Carnivorous fishes such as murrels and
catfishes may be provided with trash fishes. For adult fish, daily
supplementary feeding can be at 2% of its body weight.

Routine Management and Diseases

Analysing water parameters, replenishment of water, aeration,
regular feeding, observation for mortality and disease symptoms should be
routine checks in the management of aquaculture ponds. Diseases can be of
viral or bacterial origin or may be due to ectoparasites or endoparasites.

Unit 7. THEORIES OF EVOLUTION Topic List Zoology

12th Zoology

Poultry byproducts

Poultry and poultry products are highly perishable. Hence, due
attention has to be paid to the problems relating to processing, preservation
and marketing of poultry and poultry products for the benefit of producers,
processors and consumers. In a poultry processing unit, raw materials go as
waste in the form of blood, feathers, heads and feet. Hatchery waste
includes infertile eggs, dead embryos, and hatchery unstable chicken. Large
quantity of wet droppings are also available. Processing and using of this
byproducts will not only reduce the cost of poultry production, but also solve
the disposal problem and minimize pollution hazard. A great deal of work
has been done for processing this by-products into feather-meal, poultry
byproducts meal, hatchery byproducts meal, egg shell meal, albumin flake,
dried and poultry manure.

Poultry diseases : These birds are commonly affected by diseases such as
ranikhet, coccidiosis, fowl pox and tick fever.

Pisciculture

Pisciculture or fish culture, included under the broad term
‘aquaculture’, can be defined as the ‘farming and husbandry of economically
important fish, under controlled conditions’.
Fish farming is a productive venture. Fishes are highly nutritious
sources of easily digestible proteins (rich in lysine and methionine. They are
essential amino acids); minerals like calcium, phosphorous, iron, sodium,
potassium, magnesium and sulphur; vitamins such as A, D and health
promoting fats. Fish are the source of polyunsaturated fatty acids which are helpful in cholesterol regulation and promoting cardiac health. Fish farming
can help in integrated rural development by generating employment
opportunities.

Fish farming

Definition
Fish farming is the raising of fish for personal income or profit. Based
on the environment in which culture is done, fish farming may be categorized
as freshwater fish farming, brackish water fish farming, saltwater or marine
fish farming (mariculture).

Characters of cultivable fish

The following criteria should be considered before selecting a fish for
farming purpose.
· Rate of growth :Fish which grow to a larger size in shorter period are
suitable for culture.Eg. Carps.
· Adaptation to climate: The cultured species of fish should be able to
adapt to the local climatic conditions of the farm.
· Tolerance: The fish should have the capacity to tolerate wide fluctuations
in the physico chemical conditions such as oxygen, salinity, temperature etc
of the water.
· Acceptance of artificial feed : When more number of fish is to be accommodated
in a limited space, there is the need for supplementary feeding on
compounded diets. The fish should show ready preference for these feeds.
· Resistance:It is desirable that the cultured fish is hardy enough to resist the
common diseases and attack of parasites.
· Amiability and compatibility: The fishes proposed to be cultured
together (‘poly culture’) should be able to live together without interfering or
attacking the other.
· Conversion efficiency: The species of fish which give more edible flesh
per unit of food consumed, is preferred.

Consumer’s preference: Food preference of people vary with the
geographic regions. Hence, the species cultured should be easily marketable
locally or to the targeted consumers.

Culturable Fishes of India

Carps, Catfishes, Murrels, Tilapia etc are the main culturable fishes.
Culturable Fishes of India
Indian major carps
Carps (Kendai)
Catla catla (Catla)
Labeo rohita (Rohu)
Cirrhina mrigala (Mrigal)
Exotic (Chinese) carps
Cyprinus carpio (Common carp)
Minor Carps
Labeo bata (Bata)
Catfishes ( ‘Keluthi’)
Wallago attu (freshwater shark : ‘Valai’)
Mystus aor (Cat fish)
Clarias batrachus (Magur)
Murrels or snake heads (‘Viral’)
Channa striatus (Striped snake – head)
Tilapia
Oreochromis mossambicus (‘Jilebikkendai’)
Sport fishes (Cold – water fishes)
(i) Trouts (Order : Salmoniformes)
Salmo gairdneri (Rainbow trout)

Marine fishes

Lates calcarifer (Sea bass or cockup, ‘Koduva’)
Mugil cephalus (Grey mullet, ‘Madavai’)
Chanos chanos (Milk fish) besides these food fishes, there is an enormous
potential for the mass culture of a variety of ornamental fishes, which can
bring in high profit, also from overseas markets.

Unit 7. THEORIES OF EVOLUTION Topic List Zoology

12th Zoology

Farming methods

Poultry farming has now become very popular. It is recoginzed as an
organised and scientifically based industry with tremendous employment
potential. It plays an important part in the rural economy of India. It provides
a ready source of income to the cultivator. Besides meat and eggs, poultry
supplies feathers and rich manure.The following factors are being taken into
consideration for the growth of poultry farming 1) small initial investment
2) availability of quality chicks 3) short generation interval 4) quick, assured
and better returns compared to other livestock species 5) availability of
trained man power 6) better understanding and knowledge of the improved
and scientific methods of feeding 7) management and health control.

Rearing involves the following stages:- Selection of eggs, incubation and
hatching of eggs, brooding or care of new borns, housing of poultry, feeding
of poultry are the important steps in rearing of chickens. (Farming methods)

1. Selection of eggs:- (Farming methods)

Eggs meant for hatching and rearing must be selected
very carefully. The following points should be considered during selection of
eggs.

(1)The egg should be fertile (2) Over-sized and small sized eggs should
not be selected instead medium sized should be preferred (3) Dark-brown
shelled eggs hatch earlier than light-brown shelled eggs (4) Freshly laid eggs
are preferred for rearing.

2. Incubation and hatching: (Farming methods)

The fertilized hen’s egg undergoes development during incubation and
hatching processes. The fully formed bird emerges out of egg after a hatching
period of 21-22 days. During this period the egg must obtain optimum temperature, humidity and ventilation etc. The maintanance of newly laid eggs in optimum condition till hatching is called incubation.

The incubation is of two types namely natural incubation and
artificial incubation. In the natural incubation method, the eggs are
subjected to the care of mother. Only a limited number of eggs can be
incubated by a mother hen. In artificial incubation the eggs are maintained in
a chamber(incubator) which stimulates the optimum environmental
condition. In artificial incubation more number of eggs can be incubated than
natural incubation.

3. Brooding :- (Farming methods)

Brooding is the care and management of young chickens for
four to six weeks immediately after hatching. Like incubation, brooding also
has the natural and artificial methods. In the former, day-old chickens are left
to the care of mother and in the latter temperature controlled artificial brooder
is used.

Factors involved in brooding :

Temperature :- (Farming methods)

The hatched chicks are kept inside the incubator for about
36 hours and then transfered to artificial brooder. The optimum temperature
is 330c during the first 3 days. During the subsequent weeks of brooding the
temperature is reduced by 30c each week till it reaches 210c.
Ventilation :- Fresh air movement is important for good health and proper
growth of the chicks. Poor ventilation results in the accumulation of carbon
monoxide, ammonia and water vapour which may lead to microbial
infection. (Farming methods)

Floor space :-

Adequate floor space is to be provided for the proper
development of chicken. Minimum 500sq.cm of floor space per chickens is
to be provided. Crowding of chickens leads to poor growth and induces
cannibalistic tendencies amongst the birds.
Litter :- The floor of the brood house is layered by beds of hay, rice husk or
saw dust and this is called litter. The litter bed should be 5 to 7.5cm thick
and it must be kept dry. (Farming methods)

Light :-

To keep the brood house free from infectious germs, the brood
house must be well ventilated. Evenly distributed sunlight promotes proper
growth of the birds and formation of vitamin D.

4. Housing of poultry :- (Farming methods)

Open sided poultry is popular in our country. The
primary objective of providing housing to poultry is to protect them from
sun, rain and predators and to provide comfort. Poultry house should be
well ventilated. It should be kept cool in summer and warm in winter. The
floor of the poultry house should be moisture-proof, rat proof, free from
cracks, easily cleanable and durable.

5. Poultry feeding :- (Farming methods)

Feeding of poultry bird is an important part of rearing.
The diet of chickens must contain adequate amount of water, carbohydrates,
proteins, fats, vitamins and minerals. The food stuffs such as maize, barley,
sorghums, wheat, oil cake, rice etc are to be given in standard requirements

Computed Tomography (CT)(OR) Computerized axial tomography (CAT).

Computed tomography scan or (CT) scan :

Advantages of Computed Tomography CT over other imaging techniques

Uses of CT Computed Tomography

Related Topics in Zoology:

Unit 7. THEORIES OF EVOLUTION Topic List Zoology

ECG Electrocardiogram

Related Topics in Zoology:

Unit 7. THEORIES OF EVOLUTION Topic List Zoology

Urine Sugar analysis

Collection and preservation of Urine

Sugar Analysis

Significance of Glucose

Related Topics in Zoology:

Unit 7. THEORIES OF EVOLUTION Topic List Zoology

Haemocytometer

Haemocytometer – instruments description

Normal Range of RBCs in human is as follows

Clinical significance :

Related Topics in Zoology:

Unit 7. THEORIES OF EVOLUTION Topic List Zoology

Sphygmomanometer

Uses

Related Topics in Zoology:

Unit 7. THEORIES OF EVOLUTION Topic List Zoology

Medical Lab Techniques

Stethoscope

Uses

Related Topics in Zoology:

Unit 7. THEORIES OF EVOLUTION Topic List Zoology

Edible Fishes Of Tamilnadu

I. Fresh Water Fishes

i. Indian Major Carps (‘Kendai’ meen)

(ii) Catfishes (Order: Siluriformes-‘Keluthi’)

(iii) Murrels or Snakeheads (Order : Channiformes-‘Viral’ meen)

(iv) Tilapia (Order : Perciformes)

Related Topics in Zoology:

Unit 7. THEORIES OF EVOLUTION Topic List Zoology

Fish Pond

Types of fish ponds

1. Conditioning

2. Manuring

Feeding

Routine Management and Diseases

Related Topics in Zoology:

Unit 7. THEORIES OF EVOLUTION Topic List Zoology

Poultry byproducts

Pisciculture

Fish farming

Characters of cultivable fish

Culturable Fishes of India

Related Topics in Zoology:

Unit 7. THEORIES OF EVOLUTION Topic List Zoology

Farming methods

1. Selection of eggs:- (Farming methods)

2. Incubation and hatching: (Farming methods)

3. Brooding :- (Farming methods)

Factors involved in brooding :

Temperature :- (Farming methods)

Floor space :-

Light :-

4. Housing of poultry :- (Farming methods)

5. Poultry feeding :- (Farming methods)

Related Topics in Zoology:

Unit 7. THEORIES OF EVOLUTION Topic List Zoology