GSC201 current final term paper 2020

sc 101

Paper Time 8am

Date :10/9/20

Question no 1

Stomach brief Note ?

Answer:

Stomach

Stomach is mainly a storage organ. It also helps in digestion of proteins. Stomach has

guarded openings on either side. There is a sphincter (group of muscles) which is pyloric

sphincter that controls movement of food from stomach to intestine. The other sphincter

is present where esophagus meets stomach. Gastric glands in stomach produces gastric

juice, which contain mucus, hydrochloric acid and an enzyme called pepsinogen.

Pepsinogen is converted into pepsin which is its activated form. Pepsin converts proteins

to peptides. Protection of the stomach walls from the acid particularly is important,

mucus secreted by the stomach walls cover the stomach lining to protect it from acidic

damage.

tomach is also designed to mix up the food with enzymes and acid. Churning

movements of stomach walls thoroughly mixes the food with gastric juice. Churning

converts food to chyme, small part of which enters the small intestine by pyloric

sphincter.

Question no 2

Kidney Brief Note?

Answer:

Kidney is a bean shaped structure. A pair of kidneys is present in abdominal cavity

attached to dorsal body wall. The concave part of kidney lies towards vertebral column.

There is a depression present towards the vertebral column which is called hilus. The

concave part provides space for entrance and exit of renal artery, vein and nerves. A thin

tube ureter arises out of the concave part of kidney.

Question no 3

Importance Of Dairy and poultry?

Answer:

Dairy and poultry

Biology plays very important roles in dairy and poultry industries. Biology helps in many

ways for example:

• Improved breeding techniques and cross breeds (more vigorous and resistant).

• Improved quality and quantity yield of meat, milk, wool and eggs.

• Diagnosis and cure for diseases in farm animals.

• Biological knowledge is also helping in providing balanced food for best yield.

Question no 4:

Role of Pharynx in Digestive system?

Answer:

Pharynx

Pharynx is a part of digestive system. It lies just behind the mouth and nasal cavity and

above the esophagous and larynx. Food bolus passes through pharynx to enter the

esophagus. Pharynx helps swallowing by closing the trachea and nasal cavity pathways.

Question no 5

Arrhinues theory of Acid and Base ?

Ans:

Arrhenius concept of acid and base:

According to Arrhenius theory an acid is substance which produces H+ ions when dissolved in

water, examples; HCl, HNO3 etc.

HCl H+ + Cl-

According to this theory a base is a substance which produces OH- when dissolved in water.

Examples include NaOH and KOH.

NaOH Na+

+ OH-

When an acid and a base react, they cancel each other. This reaction is known as neutralization

and in neutralization reaction a salt and water is formed. Example;

HCl + NaOH NaCl + H2O

Acid Base Salt Water.

Question no 6:

Types Of Asexual Reproduction?

Types of asexual reproduction

Asexual reproduction involves no gametes. There are many methods of asexual

reproduction in organisms including:

Binary fission

Multiple fission

Budding

Regeneration

Vegetative propagation in plants

Question no 7

Photo chemical reaction?

Answer:

Photochemical reactions: chlorine also undergoes photochemical reactions. In these reaction a

photon of light breaks the chlorine molecule into chlorine free radicals which are chlorine atoms.

The chlorine radicals then react with other compounds such as methane.

CH4 + Cl2 CH3Cl + HCl

Question no 8

Steps Of Iran metallurgy?

Metallurgy:

It is the science and art of obtaining a metal from its ores. There are number of types of

metallurgy.

In electrometallurgy, electricity is used to obtain a metal. Electrolysis is carried out of the molten

or solution form of the ore and metal is obtained at the cathode. For example; Na is obtained by

the electrolysis of NaCl by the Downs process.

In pyrometallurgy strong heat is used to extract a metal from its ores. For example, Fe is extracted

from its ores by heating at high temperature.

Iron is extracted through pyrometallurgy in a furnace called Blast Furnace. Commonly hematite

and magnetite are used to obtain iron. A number of reactions occurs at high temperature in the

blast furnace.

The reactions occurring in blast furnace are as follows.

• Reactions in blast furnace:

Fe2O3 + CO 2Fe3O4 + CO2 (g)

Fe3O4 + CO 3FeO +CO2 (g)

FeO + CO Fe(l) + CO2 (g)

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