Following are the important nucleus function:

• It contains the cell’s hereditary information and controls the cell’s growth and reproduction.
• The nucleus has been clearly explained as a membrane-bound structure that comprises the genetic material of a cell.
• It is not just a storage compartment for DNA but also happens to be the home of some essential cellular processes.
• First and foremost, it is possible to duplicate one’s DNA in the nucleus. This process has been named DNA Replication and creates an identical copy of the DNA.
• Creating two identical copies of the host or body is the first step in cell division, where each new cell will get its own set of instructions.
• Secondly, the nucleus is the spot of transcription. Transcription is the process of creating different types of RNA from DNA. Transcription would be a lot like making copies of individual pages of the human body’s instructions that can then be passed out and read by the rest of the cell.
• The central rule of biology states that DNA is copied into RNA, which is then turned into protein.

Impulse: A large amount of force acting on an object for a short interval of time is called impulse or impulsive force. Numerically impulse is the product of force and time. Impulse of an object is equal to the change in momentum of the object.
  
Example :  When a glass vessel falls from a height on a hard floor, due to the impact of impulse because it comes to rest to break it down in a short span of time so a large force is exerted on it But if it falls on a carpet or sand, the time duration in which the vessel comes to rest, becomes more and the impact of the impulse reduces, so a less force is exerted on the vessel and it does not break.

According to the nature of the movement, motion is classified into three types as follows:

• Linear Motion: In linear motion, the particles move from one point to another in either a straight line or a curved path.
• Rotary Motion: Rotatory motion is the motion that occurs when a body rotates on its own axis.  
• Oscillatory Motion: Oscillatory motion is the motion of a body about its mean position.

Let us assume that Abdul is travelling x kilometer distance while going to school.

Distance = Speed x Time
1)When it's average speed is 20 km/hr

Given:

A runner travels around rectangle track.

length of track= 50 meters

width of track = 20 meters

runner travels around the rectangle track two times  and finally finishes back at the starting point.

To Find:

Distance and displacement of runner.

Solution:

Distance traveled by runner = 2 (perimeter of rectangle)

Perimeter of rectangle = 2(L+B)

L = 50 m     B = 20 m

perimeter of rectangle = 2(50+20)

                                       = 140 m

Distance traveled by runner = 2 (perimeter of rectangle)

                                                = 280 m

Displacement :

It is the shortest distance between initial and final position or the shortest path of travel

initial position of runner = final position of runner

displacement = 0 m

Distance traveled by runner = 280 m

Displacement traveled by runner = 0 m

Euclid was an ancient Greek mathematician who lived in the Greek city of Alexandria in Egypt 

Euclid is often referred to as the 'father of geometry' and his book <i>Elements</i> was used well into the 20th century as the standard textbook for teaching geometry.

The basic processes of life include organization, metabolism, responsiveness, movements, and reproduction. In humans, who represent the most complex form of life, there are additional requirements such as growth, differentiation, respiration, digestion, and excretion. All of these processes are interrelated.

The human body consists of a bony skeleton and muscles. The three main parts of the body are: the head, the trunk and the limbs (extremities). The head is composed of the cranial and facial parts. It contains the brain, the centre of the nervous system.

Plasma is a state of matter that is often thought of as a subset of gases, but the two states behave very differently. But unlike ordinary gases, plasmas are made up of atoms in which some or all of the electrons have been stripped away and positively charged nuclei, called ions, roam freely. Plasma is considered as the fourth state of matter. Plasma is similar to the gas. Particles of plasma are made of free electrons and ions.

• Velocity – Time Graphs:

The variation in velocity with time for an object moving in a straight line can be represented by a velocity-time graph. In this graph, time is represented along the x-axis and the velocity is represented along the y-axis. If the object moves at uniform velocity, the height of its velocity-time graph will not change with time. It will be a straight line parallel to the x-axis. To determine the distance moved by the car from its velocity-time graph, the area under the velocity-time graph gives the distance (magnitude of displacement) moved by the car in a given interval of time.

Matter can be classified as solid, liquid and gas on the basis of inter-molecular forces and the arrangement of particles. These three forms of matter can be converted from one state of matter to another state by increasing or decreasing pressure and temperature. For example, Ice can be converted from solid-state to a liquid state by increasing the temperature.

• States of Matter:

On the basis of physical states, all the matter can be classified into three groups – solids, liquids and gases. Examples of solids, liquids and gases are:

1. Sugar, sand, iron, wood, rocks, minerals and ice are the examples of solids.
2. Water, milk, oil, kerosene, petrol and alcohol are liquids.
3. Air, oxygen, hydrogen, carbon dioxide and steam are gases.

• The Solid State:

Properties of solids:

1. Solids have a fixed shape and a fixed volume.
2. Solids cannot be compressed much.
3. Solids have high densities. They are heavy.
4. Solids do not fill their container completely.
5. Solids do not flow.

• The Liquid State:

Properties of liquids:

1. Liquids have a fixed volume but they have no fixed shape.
2. Like solids, liquids cannot be compressed much.
3. Liquids have moderate to high densities. They are usually less dense than solids.
4. They do not fill their container completely.
5. They generally flow easily.

• The Gaseous State:

Properties of gases:

1. Gases have neither a fixed shape nor a fixed volume.
2. They can be compressed easily.
3. They have low densities.
4. They fill their container completely.
5. They flow easily.

Lysosomes

• The sac-like structures in a cell surrounded by membrane are called lysosomes.
• They keep the cells clean by digesting and breaking the outside materials like bacteria, food entering the cell or worn-out cell organelles into small pieces.
• They can digest these organic materials due to the presence of strong digestive enzymes that can brreak down organic compounds. Therefore, lysosome is also known as a suicide sac.
• Many scientists believe that lysosomes are not present in plant cells and their function of lysosomes in plants is performed by vacuole.

Lysosomes are membrane-bound sacs filled with digestive enzymes. They are a kind of waste disposal system of the cell. They help to keep the cell clean by digesting any foreign material as well as worn-out cell organelles. Foreign materials entering the cell, such as bacteria or food, as well as old organelles end up in the lysosomes, which break them up into small pieces because they contain powerful digestive enzymes capable of breaking down all organic material. If their covering membrane breaks as it happens during injury to cell, the digestive enzymes will spill over the cell contents and digest the same. As lysosomes are organelles which on bursting can kill cells possessing them, they are called suicide bags.

Plasma membrane called a selectively permeable membrane because it regulates the movement of substances from within to outside of the cell. This means that the plasma membrane allows the entry of some substances while preventing the movement of some other substance.

It is given that the ratio of hydrogen and oxygen by mass to form water is 1:8. Then, the mass of oxygen gas required to react completely with 1 g of hydrogen gas is 8 g. Therefore, the mass of oxygen gas required to react completely with 3 g of hydrogen gas is 8 — 3 g = 24 g.

Sponge is compressible because it is having minute pores in which air is trapped .on presssing the air is expelled. it is still considered as a solid because it has a definite volume and shape does not changes unless compressed.

Molecules -

1. Molecules refers to combinations for more than 1 atom.

2. A molecule is molecular level and have its chemical properties.

3. It is at the chemical level that represents chemical properties of that element through out the reaction.

Particles -

1. Particles are not clear word in their sense. Particles refer to any assumed small thing that exist

2. It is not necessary that a particle have its own chemical properties.

3. It is not chemical level of organisation. It can be notices with nacked eyes or using simple microscope.