The prochordates do not have a Cranium or skull. They are referred to as Acrania.

1. Laws of conservation of mass:
In a chemical change the total mass of the reactant is equal to the total mass of the products.
2. Law of definite proportion:
"A pure chemical compound prepared by any method consists of the same elements combined together in the fixed proportion by mass".
3. Law of multiple proportion: 
When two elements A and B combine together to form more than one compound, then masses of A which separately combines with a fixed mass of B are in simple ratio.
4. Laws of Reciprocal proportion:
"If two elements combine separately the same weight of a third element, the ratios of the masses in which they do so are either the same or a simple multiple of the mass ratio in which they combine.
5. Gay Lussac's law of combining volumes:
Whenever gases react together, the volumes of the reacting gases as well as the products bear a simple whole number ratio, provided all the volumes are measured under similar conditions of temperature and pressure.

\(_{ a }{ { \mu }_{ g } }=\frac { 3\times { 10 }^{ 8 } }{ 2\times { 10 }^{ 8 } } =\frac { 3 }{ 2 } \) = 1.5

Certain soilds change directly to gas without passing through the liquid state. The direct change of a solid to gas is called sublimation.
Example: dry ice, naphthalene, iodine.

A standard unit is defined as a specific magnitude of a physical quantity that has been adopted by law or convention.

Velocity is the rate of change of displacement.

Rf value is defined as the ratio of the distance travelled by the solute spots to the distance travelled by the solvent
 Rf = \(\frac { Distance\ travelled\ by\ the\ solute }{ Distance\ travelled\ by\ the\ solvent } \)

1. The units named after scientists are not written with a capital intial letter.
Ex: newton, henry, ampere and watt
2. The symbols of units named after scientists should be written by the initial capital letter.
Ex: N for newton, H for henry, A for ampere and W for watt.
3. Small letters are used as symbols for units not derived from a proper noun.
Ex: m for metre, kg for kilogram
4. No full stop or other punctuation marks should be used within or at the end of the symbols.
Ex: 50 m and not as 50 m.
5. The symbols of the units are not expressed in plural form.
Ex: 10 kg not as 10 kgs.
6. Accepted symbols should only be used.
Ex: ampere should not be written as amp and second should not be written as sec.

Height of object h₁ = 2 cm
Height of real image h₂ = -3 cm
Magnification   m =\(\frac { { h }_{ 2 } }{ { h }_{ 1 } } \)
= \(\frac { -3 }{ 2 } \)
= -1.5
We know that,  m = \(\frac { -v }{ u } \)
here, object distance u = - 16 cm 
Substituting the value, we get
 -1.5 = - \(\frac { v }{ (-16) } \)
-1.5 =  \(\frac { v }{ (-16) } \)
v = 16 \(\times\) -1.5
v = -24 cm
The position of image is 24 cm in front of the mirror (negative sign indicates that the image is on the left side of the mirror).

Role of Food control agencies in India:
a) FCI - i) Effective price support operations for safeguarding the interest of farmers.
ii) Regulate the market price to provide food grains to consumers at reliable price.
b) ISI - Certifies industrial products like electrical appliances like switches, wiring cables, electric motor and kitchen appliances etc.
c) AGMARK - Certifies agricultural and livestock products like cereals, essential oils, pulses, honey, butter etc.
d) FPO - Certifies the food products like juice, jams, sauce, canned fruits and vegetables, pickles etc.
d) FSSAI - Responsible for protecting and promoting the public health through regulation and supervision of food safety.

Finding the outer diameter of the tea cup:
1. Place the tea cup between the outside jaws.
2. Note the reading of main scale and vernier coincidence. Tabulate the readings.
3. The outer diameter of the tea cup is calculated by MSR + (VC x LC).
4. Repeat the experiment and find the average diameter.
Finding the inner diameter of the tea cup:
1. Place the tea cup between the inside jaws.
2. Note the reading of main scale and vernier coincidence.
3. Tabulate the readings.
4. The inner diameter of the tea cup is calculated by MSR + (VC x LC).
5. Repeat the experiment and find the average diameter.

The thickness of tea cup = outer reading - inner reading = __________ mm