Sai Science academy

Cell  is the basic fundamental and structural unit of life. All living organisms areade up of one or more cells. Microscope  is an instrument used to see objects which are too small to be seen through our Naked eyes.  Cells  are highly organised and all their functions an regulated. It is not just the rate of cell division that is controlled, but also the rate of cell death. If cells are longer needed, they commit suicide by activating an intracellular death program. This process is called programmed cell death or apoptosis. Robert Hooke  in  1665  observed the slices of cork under a microscope, he coined the name as  cell . Anton Van Leeuwenhook  invented  microscope   Mathias Schleiden proposed that all plants are made up of cells. Cell theory was proposed by Schleiden and Schwann. The main postulates of cell theory are: • All living organisms are composed of one or more cells.  • Cell is the basic unit of structure, function...

 There is a Black hole at the centre of the galaxy At center of MILKY WAY GALAXY a Black hole named SAGITTARIUS A  SAGITTARIUS A- Sagittarius A is a bright and very compact astronomical radio source at the Galactic Center of the Milky Way. It is located near the border of the constellations Sagittarius and Scorpius, about 5.6° south of the ecliptic, visually close to the Butterfly Cluster and Shaula. Distance to Earth: 25,640 light years Radius: 22 million km Discovered: 13 February 1974 Coordinates: RA 17h 45m 40s | Dec -29° 0′ 28″ Constellation: Sagittarius Discoverers: Reinhard Genzel, Andrea M. Ghez, Harry Clive Minnett, Robert Brown, Bruce Balick  So for a galaxy there is a Black hole at the center  Hi viewers This is SSA from Learn it, Sai group, I try to spread information through my blogs and websites. Our motto of this group is Information should be free. I will reach u with a lot of topics covered. Visit my blogs and stay tuned  Follow my blog  ...

 Welcome to SSA From learn it  Charge - Charge is the property of matter that produces ans experiences electrical and magnetic effects   Point charge:- when linear size of charged body is much smaller than the distance under consideration, the size may be ignored and the charges body is called point charge.  Electrification - The process of giving charge to a body is called electrification. Methods of electrification  a) Charging by friction Two glass rods rubbed with silk or wool cloth are brought close to each other, they repel each other  The two strands of wool or two pieces of silk cloth, with which rods were rubbed, also repel each other. However, the glass rod and wool attracted each other. Similarly, two plastic rods rubbed with cat's fur repelled each other but attracted the fur. On the other hand, the plastic rod attracts the glass rod and repel the silk or wool with which the glass rod is rubbed. The glass rod repels the fur. In this process whe...

 Q1) Light   a ray or a wave or a particle Ans- In first of classes light is taught to us as a ray and it travels in a straight line  But then after in further classes its told light is a wave   Then again in higher classes it is told light is a particle Now we will get confused that is light a ray or a wave or a particle  Light is a particle called photon,  It is also a electromagnetic wave, a transverse wave Q2) How light travels in higest speed? Ans- Light is made of a particle called photon. Photon  is a massless particle, that means it has no mass, now we know that if a particle has no mass then there will be no resistance force (i.e. Friction, gravity) nothing will stop this Photon, so that's the reason light travels very fast. Hi viewers This is SSA from Learn it, Sai group, I try to spread information through my blogs and websites. Our motto of this group is Information should be free. I will reach u with a lot of topics covered. Visit my...

 Welcome to SSA  Q1) Can we hear in space Ans-Sound needs a medium to travel, space is almost vaccum, so sounds can't travel in space, so we can't hear any sound  Did you know!  If sound travels through space then sounds from Sun can reach earth and it can cause worst effects on human hearing, because on Sun a lot of volcanic activities happening every minute, now we can image the sound of volcano eruptions travelling to earth then none of the humans can hear as every time there is unnecessary sound  Q2) How do aeroplanes fly  Ans- Aeroplanes work in a principle called lift it is about pressure difference, now I will tell what's lift When an aeroplane starts to run on runway then the air above the wings blow off , this creates a low pressure region above the wing and a high pressure at bottom, so due this pressure differences aeroplanes lift off, this maintains the balance of aeroplanes Did you know! Aeroplanes change their direction through a pane at the b...

 The larynx, commonly called the voice box or glottis, is the passageway for air between the pharynx above and the trachea below. ... The larynx plays an essential role in human speech. During sound production, the vocal cords close together and vibrate as air expelled from the lungs passes between them.

  Crop production and management Crops - When a plant of same kind is cultivated at one place on a large scale is known as crop Based on seosons which they grow, there are three kinds of crop- Kharif crop, Rabi crop and Zaid crop Kharif Crops: The crops which are grown in the rainy season (i.e., from June to September) are called Kharif crops. Paddy, maize, soybean, groundnut, and cotton are Kharif crops. Rabi Crops: The crops are grown in the winter season (i.e., from October to March) are called rabi crops. Examples of rabi crops are wheat, gram, pea, mustard, and linseed. Zaid Crops (or Summer Crops): The crops grown in the summer season are ( called zaid crops. Moong, muskmelon, watermelon, cucumber, gourd and bitter gourd are examples of zaid crops. Agricultural practices Soil Preparation:  It involves loosening and tilling of the soil (i.e., ploughing and watering). Sowing:  Sowing is the process of putting seeds in the soil. Adding Manure and Fertilisers:  The...