Mostly leaves are arise from the stem in plants. In ginger the arial leaves are arise from underground and also the scaly leaves are also present in the rhizome. So ginger is consider as stem.

Silk is the strongest natural fibre. Moreover, it is thin, lightweight, easy to pack, fire resistant and springy, So silk is used to manufacture parachute.

It takes 16-17 generations to see the plastic bag finally broken.

(i) PSLV - Polar Satellite Launch Vehicle.
(ii) GSLV - Geosynchronous Satellite Launch Vehicle

1. BC,CD
2. AB, BC
3. Angle of incidence corresponding to the ray BC \(\angle \)i = 90°- 39° = 51°
4. Angle of incidence corresponding to the ray CD = 39°
So, the angle of reflection corresponding to the ray CD = 39° ( \(\angle \)i = \(\angle \)r).

Merits of five kingdom:
i) This system of classification is more scientific and natural.
ii) This system of classification clearly indicates the cellular organisation, mode of nutrition and characters for early evolution of life.

The building wall is made up of numerous bricks. In similar manner, all living organisms made up of cell. Cell is the fundamental life of organism. So cell is very important for us.

Solar eclipse is a periodic changes. It repeats itself after a definite period of time. So it is called as periodic change.

Electrical conductivity is the measure of a material's ability to conduct an electric current. It is commonly represented by the Greek letter σ(sigma). The S.I Unit of electrical conductivity is Siemens/meter(S/m).

No. Srinath is not suffering from fever. No person always has exactly the same temperature at every moment of the day. Temperature cycle regularly up and down through the day according to activities and external factors.

Density of cylinder \(=\frac { mass \ of \ cylinder }{ volume \ of \ cylinder }\)
\(=\frac{280}{4}=70 \mathrm{~kg} / \mathrm{m}^{3}\)

Atomic number Z = 9
No. of neutrons n = l0
Mass number A = ?
No. of neutrons n = A - Z 
Mass number A = n + Z
= 10 + 9 = 19
The symbol of the element is ₉Fe¹⁹ Fluorine

i. The regular hair wash and massage of the scalp will remove the dead skin cells, excess oil and dust.
ii. Rinsing the hair well with clear water and using good toothed comb for hair dressing is highly essential for their maintenance.

An object undergoes uniform acceleration when the change (increase or decrease) in its velocity for every unit of time is the same.