The given number series follows a pattern that

196, 169, 144, 121, 100, 81, ?

    -27  -25   -23   -21  -19  -17

=> 81 - 17 = 64

Therefore, the series is 196, 169, 144, 121, 100, 81, 64.

The ozone layer is a region of Earth's Stratosphere that absorbs most of the Sun's ultraviolet (UV) radiation. It contains high concentrations of ozone (O3) in relation to other parts of the atmosphere, although still small in relation to other gases in the stratosphere.

The Atmosphere is divided into 4 layers according to major changes in temperature. They are :

1. Troposphere,

2. Stratosphere,

3. Mesosphere  and

4. Thermosphere.

The farther away from earth, the thinner the atmosphere gets.

The nucleus of hydrogen consists of only a single proton.

Its parts are a single negatively-charged electron that circles a single positively-charged nucleus of the hydrogen atom.

The electron is bound to the nucleus by the Coulomb force.

Russia is the Largest country of the World by Geographical Area.

Top 10 largest countries of the World :

1. Russia

2. Canada

3. United States of America

4. China

5. Brazil

6. Australia

7. India

8. Argentina

9. Kazakhstan

10. Algeria

When all 10 of the world's largest countries are taken together, they total 49% of the earth's entire 149 million square kilometres of land.

Here Homologous Means having the same relation or relative position or structure. 

Here in snakes poison is in glands and here salivary glands are in Vertebrates.

The single-step income statement emphasizes

1. total revenues and total expenses.

2. Revenues

3. Expenses

4. Net income

The primary advantage of the single step fromat lies in its simple presentation and the absence of any implication that one type of revenue or expense item has priority over another.

Here Lizard is a type of Reptiles whereas Orchid is a type of flowers. Other than Orchids all are parts of Plants.

Hence, Reptile is to Lizard as Flower is to Orchids.

Let the five consecutive odd numbers be x-4, x-2, x, x+2, x+4

According to the question,

Difference between square of the average of first two odd number and the of the average last

two odd numbers is 396

i.e, x+3 and x-3

$$\begin{gathered} ⇒x + 32 - x - 32 = 396 \\ ⇒ x2 + 9 + 6x - x2 + 6x - 9 = 396 \\ ⇒ 12x = 396 \\ ⇒ x = 33 \end{gathered}$$

Hence, the smallest odd number is 33 - 4 = 29.