Life_Science_Answers

[Shaa-Baaz]

1. what are the uses of biotechnology in improving human health?
* In Vaccine :- tissues culture based vaccine can be produced in mass scale
- vaccines - highly effective & thermo stable.
- because of new technqui used in production, it will be avle to retain its potency in normal conditions.
- some vaccines where biotechnology used -- polio vaccines, plasma--derived hepatitis B vaccines, contraceptive vaccine, rabbies vaccine etc.

* In Diagnostics :- used for effective diagnosis of disease.
- techniques for detection of malaria, filariasis, typhoid, pregnancy, blood grouping etc.

* In Medicines :- recombinant --DNA techniques in production of protein pharmaceuticals, insulin, growth hormones, interferons, blood clothing factors.

* In Gene Therapy :- in replacing the defective gene with normal gene.


4. Name the different types of carbohydrates?
carbohydrate are 3 types . they are :
a) monosaccharides : - these are simple sugars, such as glucos & fructose.
- both have the same molecular formula C6H12O6, but the atoms are arranged differently in their molecule.
- monoccharides are found in honeu & most juicy fruits.
- glucose is also present in the blood of vertebrates
- glucose is the most common product of photosynthesis.

b) diasaccharides :are double sugar.ex : maltose, sucrose & lactose.
- sucrose is common in flowering plants .
- it is extracted from sugarcane & sugar beets.
- lactose is present in milk of mammals.
- maltose is formed by the breakdown of starch.
- mammals ingest their first carbohydrates as lactose present in their mother's milk.

c) Polysaccharides :
these are starch, glycogen, cellulose, chitin.
- starch & cellulose are common in plants.
- glycogen & chitin are more common in animals.
- cellulose is the basic material of plant cell walls.

5. what is ELISA test?-
the standard 'screening test' for HIV is the enzyme linked immunosolvent assay (ELISA). this is an extremely good screening test with a sensitivity of 99.5%. most diagnostic laboratories use a commercial ELISA kit which contains antigents from HIV.

6. what is the function of incubator?-
in function is to help sustain the life of prematurely born babies who, because of their low weight & weak general constittution, have dimnished viability.

7. what is artificial blood?-
it is an emulsion of an oxygen carrying compound, a colloidal substance, plasma expander, electrolytes & a few other buffer compunds.

8. why is alcohol used in cough syrups?
most cough syrups contain menthol & natural extracts, for carminative & antitussive actions. these substances are water-insoluable & so alcohol is used as a solvent.

9. why does the lotus leaf not get wet?
lotus leaf does not get wet beacuse, due to outerlayers of cells in the epidermal layer of leaves. they contain cellulose, which get converted to cutin which is layer of wax-like substances which are simple lipids.

10. why are some potions of sugarcane is red?
it is due to fungal disease called red rot caused by the organism glomerella tucumanensis.

11. how does firefly emit light?
in glow-worms , a combination of ATP & oxidative energy is used in a set of reactions that convert chemical energy into light energy.
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[Shaa-Baaz]

1. Why does a piece of iron get rusted if left exposed in the open ?
Ans : Iron piece rusts is left exposed in the open bcz, it reacts with oxygen in the air, forming iron oxide ---- a compound of iron & oxygen.

2. Why can petrol fire not be put out with water ?
Ans : Petrol is a hydro carbon which remains isolated with water & is having less density. So when water is poured petrol floats on it & keeps on burning.
The temperature of the burning petrol flaots is so high that water poured on the petrol fire is evaporated before it extinguishes the fire.

3. Ice packed is saw dust does not melt quickly. Y ?
Ans : Saw dust is bad conductor of heat & protects the ice from the external heat & hence from melting away quickly.

4. White light passing through a glass prism gives rise to a coloured pattern on the wall. Y ?
Ans : White light is made up of seven colors. Rays of different colors refract / bend along different paths & fall on different points on the wall forming a colored pattern known as spectrum.

5. A boatman pushes the bank with his pole.Y?
Ans : Action & reaction being equal & opposite, the bank will pushes the boat away from it.

6. A burning candle get extinguished when covered with a tumbler.Y?
Ans : A burning candle gets extinguished when covered with a tumbler bcz, the supply of oxygen is cut-off & the flame goes out.

7. Y do u see rainbow after rain ?
Ans : The water drops suspended in the atmosphere act as prism & disperse light into seven colors.

8. A metal tea-pot has an ebony handle.Y?
Ans : Ebony being bad conductor of heat, the handle does not get hot.

9. Y is one's breath visible in winter, but not in summer?
Ans : In winter the water vapour contained in the breath condenses into smaller droplets of water, which bcm visible. In summer it is not so.

10. The weight of a man on the surface of the moon will be only about one-sixth of his weight on the earth.Y?
Ans : The gravity of the moon is one-sixth that of the earth.so only it is so.

11. Y is it easier to roll a barrel than to pull it along the road?
Ans : Slipping resistence is much more than rolling resistence.

12. Y is the flash of lightning seen before teh sound of thunder is heard?
Ans : because , light travels faster than sound.

13. How does a soda water straw work?
Ans : When we suck through soda water straw, low pressure is created inside the straw. The liquid outside rushes in to balance the difference.

[Shaa-Baaz]

1.How does a thermos flask keep a hot liquid hot & cold liquid cold?
Ans : It is double-walled vessel in which the inner surface of the outer vessel & the other surface of teh inner vessel are silvered so as to prevent radiation of heat.
The space between the walls of the two vessels ios made of vaccum to prevent the escape of heat by conduction / convection.

2. A parachute enables a person to descend in safety in case of an accident to aircraft?
Ans : A man falls to earth bcz, of the gravitational pull of teh earth. The parachute offers considerable resistence to that gravity, thereby slowing down the speed of the descending man. The parachute thus enables a person to descend in safety.

3. Y does an electric bulb make a bang when it is broken?
Ans : An electric bulb has a partial vaccum. When it is broken air rushes in to take the place of teh vaccum,hence it bangs.

4. Y does a ship made of steel float though a steel ball sinks?
Ans : The ship displaces more water then its own weight whereas the weight of the water displaced by a steel ball is much less than the weight of the steel ball.

5.Y does Star twinkles?
Ans : 2 reasons : a) The light from the stars passes through several mediums. b) our vision has a tendency to distract.

6.Y is it easier to swim in a sea than in river?
Ans : The density of the sea water is higher than the density of the river water.

7.Thick glass tumblers often crack when very hot liquids r poured into them.Y?
Ans : The inner layer tends to expand , more rapidly than the outer layer this producing phenomenon of unequal expansion resulting in cracks due to the resulting pressure.

8.Y does the water gets cooled in an earthen pitcher?
Ans : Pitchers have pores through which water percolates which evaporates.During evaporation heat is taken away & the waetr gets cooled.

9. Y does hard water not readily form lather with soap?
Ans : Hard water contains the sulphates & chlorides of magnesium & calcuim, which form insoluble compounds with soap.

[Shaa-Baaz]

What is the strongest muscle in the human body?

There is no one answer for this question since there are different ways to measure strength. There is absolute strength (maximum force),
dynamic strength (repeated motions), elastic strength (exert force quickly), and strength endurance (withstand fatigue).
There are three types of muscles in the human body: cardiac, smooth and skeletal.

Cardiac muscle makes up the wall of the heart and is responsible for the forceful contraction of the heart. Smooth muscles make up the walls of the intestine, the uterus, blood vessels, and internal muscles of the eye. Skeletal muscles are attached to the bones and in some areas the skin (muscles in our face). Contraction of the skeletal muscles helps limbs and other body parts move.

Most sources state that there are over 650 named skeletal muscles in the human body, although some figures go up to as many as 840. The dissension comes from those that count the muscles within a complex muscle. For example the biceps brachii is a complex muscle that has two heads and two different origins however, they insert on the radial tuberosity. Do you count this as one muscle or two?

Although most individuals have the same general set of muscles, there is some variability from one person to another. Generally, smooth muscles are not included with this total since most of these muscles are at cellular level and number in the billions. In terms of a cardiac muscle, we only have one of those- the heart.

Muscles are given Latin names according to location, relative size, shape, action, origin/insertion, and/or number of origins. For example the flexor hallicis longus muscle is the long muscle that bends the big toe:

Flexor = A muscle that flexes a joint
Hallicis = great toe
Longus = Long
The following are muscles that have been deemed the strongest based on various definitions of strength (listed in alphabetical order):

External Muscles of the Eye
The muscles of the eye are constantly moving to readjust the positions of the eye. When the head is in motion, the external muscles are constantly adjusting the position of the eye to maintain a steady fixation point. However, the external muscles of the eye are subject to fatigue. In an hour of reading a book the eyes make nearly 10,000 coordinated movements.

Gluteus Maximus
The gluteus maximus is the largest muscle in the human body. It is large and powerful because it has the job of keeping the trunk of the body in an erect posture. It is the chief antigravity muscle that aids in walking up stairs.

Heart
The hardest working muscle is the heart. It pumps out 2 ounces (71 grams) of blood at every heartbeat. Daily the heart pumps at least 2,500 gallons (9,450 liters) of blood. The heart has the ability to beat over 3 billion times in a person’s life.

Masseter
The strongest muscle based on its weight is the masseter. With all muscles of the jaw working together it can close the teeth with a force as great as 55 pounds (25 kilograms) on the incisors or 200 pounds (90.7 kilograms) on the molars.

Muscles of the Uterus
The uterus sits in the lower pelvic region. Its muscles are deemed strong because they contract to push a baby through the birth canal. The pituitary gland secretes the hormone oxytocin, which stimulates the contractions.

Soleus
The muscle that can pull with the greatest force is the soleus. It is found below the gastrocnemius (calf muscle). The soleus is very important for walking, running, and dancing. It is considered a very powerful muscle along with calf muscles because it pulls against the force of gravity to keep the body upright. This muscle keeps an individual from falling backwards.

Tongue
The tongue is a tough worker. It is made up of groups of muscles and like the heart it is always working. It helps in the mixing process of foods. It binds and contorts itself to form letters. The tongue contains linguinal tonsils that filter out germs. Even when a person sleeps, the tongue is constantly pushing saliva down the throat.