The members of the Third estate were unhappy with the prevailing conditions because they paid all the taxes to the government. Further, they were also not entitled to any privileges enjoyed by the clergy and nobles. Taxes were imposed on every essential item. Life was harsh for the members of the Third estate because they also had to pay additional taxes to their feudal lords. 

The important ribosome function includes:

1. It assembles amino acid to form proteins that are essential to carry out cellular functions.
2. The DNA produces mRNA by the process of DNA transcription.
3. The mRNA is synthesised in the nucleus and transported to the cytoplasm for the process of protein synthesis.
4. The ribosomal subunits in the cytoplasm are bound around mRNA polymers. The tRNA then synthesises proteins.
5. The proteins synthesised in the cytoplasm are utilised in the cytoplasm itself, the proteins synthesised by bound ribosomes are transported outside the cell.

The plasma membrane is flexible and is made up of organic molecules called lipids and proteins. According to fluid mosaic model, plasma membrane is made up of a bilayer of phospholipids. There are two types of protein molecules: Intrinsic Proteins, which completely covers the lipid bilayer and Extrinsic Proteins, which occur either on the outer surface or on the inner surface of the lipid membrane.

The fluid mosaic membrane has been described as “a number of protein icebergs floating in the sea of lipids”.

An iron almirah is a solid at room temperature (25°C) because:

1. It has a definite and rigid shape and
2. Fixed volume like a solid at room temperature.
3. On applying external force the shape does not get deformed

Animal tissues are of four types, viz. epithelial tissue, connective tissue, muscular tissue and nervous tissue.

Epithelial Tissue

Epithelial tissues form the protective covering and inner lining of the body and organs. These tissues were the first to evolve during evolution and were first formed during embryonic development. They develop from the ectoderm, mesoderm and endoderm of the embryo.

Connective Tissue

Connective tissues develop from the mesodermal cells of the embryo. they support and bind other tissues in the body. These are made up of three components:

• Intercellular Matrix: It is made up of mucopolysaccharide, specifically hyaluronic acid.
• Cells: The major cells include fibroblasts, adipocytes, plasma cells and mast cells.
• Fibres: Connective tissues are made up of three types of fibres, namely, collagen fibre, elastic fibre, reticular fibre.

Muscular Tissue

The muscular tissue develops from the mesoderm of the embryo. It is classified into three types:

• Cardiac
• Smooth
• Skeletal

The endoplasmic reticulum is also called as ER. It is of two forms: RER and SER. RER stands for Rough ER and SER stands for Smooth ER. Rough ER has ribosomes attached to it and thus, helps in protein synthesis. ERs have several functions in cells. One of their major functions is to act as a channel for transport. Secretory proteins, mostly glycoproteins, are moved across the endoplasmic reticulum membrane.

Cell organelles are membrane bound little structures that perform activities in the cell. The various cell organelles are – Endoplasmic Reticulum, Ribosomes, Golgi apparatus, Lysosomes, Mitochondria, Plastids, Vacuoles, Peroxisomes and Centrosome.

1. Endoplasmic Reticulum:

The endoplasmic reticulum (ER) is a large network of membrane-bound tubes and sheets which looks like long tubules or round or oblong bags (vesicles). There are two types of ER– rough endoplasmic reticulum (RER) and smooth endoplasmic reticulum (SER). RER looks rough under a microscope because it has ribosomes attached to its surface. The ribosomes are the sites of protein manufacture. The SER helps in the manufacture of fat molecules or lipids. Some of these proteins and lipids help in building the cell membrane. This process is known as membrane biogenesis. Some other proteins and lipids function as enzymes and hormones.

Functions:

1. 1. It serves as channels for the transport of materials between various regions of the cytoplasm or between the cytoplasm and the nucleus.
   2. The ER also functions as a cytoplasmic framework providing a surface for some of the biochemical activities of the cell.
   3. SER plays a crucial role in detoxifying many poisons and drugs.
   4. It forms supporting skeletal framework of the cell.
   5. Golgi Apparatus:

   6. The Golgi apparatus was first described by Camillo Golgi. Golgi apparatus consists of a set of membrane-bounded, fluid filled vesicles, vacuoles and flattened cisternae. Cisternae are usually stacked together (placed one above the other) in parallel rows. Golgi apparatus exists as an extensive network near the nucleus in the animal cells. However, the plant cells contain many freely distributed subunits of Golgi apparatus, called dictyosomes. The Golgi apparatus arises from the membrane of the smooth endoplasmic reticulum, which in turn, originates from the rough endoplasmic reticulum.

      Functions:

   7. 1. Its functions include the storage, modification and packaging of products in vesicles.
      2. In some cases, complex sugars may be made from simple sugars in the Golgi apparatus.
      3. The Golgi apparatus is also involved in the formation of lysosomes, cell wall and plasma membrane.

Mass of the motor car = 1200 kg

As only two persons manage to push the car,hence, the acceleration acquired by the car is given by the third person alone.

Acceleration produced by the car, when it is pushed by the third person,
is a = 0.2 m/s²

Let the force applied by the third person be F.

From Newton’s second law of motion: Force = Mass × Acceleration

So,F = 1200 × 0.2 = 240 N

Thus, the third person applies a force of magnitude 240 N. Hence, each person applies a force of 240 N to push the motor car.

Water has the strongest intermolecular forces (hydrogen bonds) of all the substances used.

a)Take out a bottle of soft drink from the refrigerator and place it on the table.

b)Observe it for few minutes.

c)you will see small drops of water appearing on the outer surface of the bottle.

d) This is because water vapour present in the air condenses and forms small drops of water. 

e) This activity proves that air contains water vapour. 

The body needs a way to get oxygen in and carbon dioxide out, which is through diffusion. The carbon dioxide concentration is much greater in your blood than the alveoli. So, by the rule of diffusion, the carbon dioxide moves from the blood to the alveoli, where it can be exhaled through the lungs. Respiration refers to the exchange of gases between a living organism and its environment, while breathing is the process that moves air into and out of the lungs. Breathing (or pulmonary ventilation) has two phases - inspiration (or inhalation) and expiration (or exhalation).

The 'temperature of a substance' remains constant during its melting and boiling point because the change in any state of matter as n solid to liquid or the liquid to a gas involves crossing the 'latent heat of fusion' which causes a change in the intermolecular spacing of the molecules in the substance.

LATENT HEAT OF FUSION- the amount of heat energy required to change 1kg of solid into liquid under the given atmospheric pressure at it's melting point is called latent heat of fusion

The first equation of motion (Vf =Vi + at) deals with final velocity, initial velocity, acceleration and time. We can use the 1st equation of motion to find final velocity, initial velocity, acceleration and time. A constant slope of a position-time graph indicates a constant velocity. A varying slope of a position-time graph indicates a changing velocity. The direction of the slope of the position-time graph indicates the sign of the velocity. For example, if it slopes downward, from left to right, the velocity is negative.

Gas exchange is the delivery of oxygen from the lungs to the bloodstream, and the elimination of carbon dioxide from the bloodstream to the lungs. The walls of the alveoli actually share a membrane with the capillaries in which oxygen and carbon dioxide move freely between the respiratory system and the bloodstream. The oxygen enters the bloodstream from the alveoli, tiny sacs in the lungs where gas exchange takes place. The transfer of oxygen into the blood is through simple diffusion. The oxygen molecules move, by diffusion, out of the capillaries and into the body cells.