• Respiratory system is responsible for the process of respiration. It involves exchange of gases, i.e, oxygen and carbon dioxide between body and surrounding. The body can't store oxygen, so, it is vital process and it is occurs all the time.
• The body takes up oxygen and passes it to whole body through blood.
• Respiratory system is divided into 2 major parts, upper respiratory tract and lower respiratory tract.  
• Upper respiratory tract is composed of nose, pharynx and larynx.

Nasal cavity traps the dust particles.  Air passes to lungs through pharynx, and larynx is essential for speech

• Lower respiratory tract is composed of the trachea, the lungs, and bronchioles including alveoli.
• Trachea is the main pathway to lungs.  Lungs are main site of gaseous exchange, they gives oxygen to capillaries and exhale carbon dioxide, Bronchi supply the lungs with air.  Bronchioles are the branches of bronchus.  They further branches into primary and secondary bronchioles.  And they finally terminate into alveoli.  Diaphragm contracts and relaxes to allow air into the lungs.

The population of tiger decreases and the population of grass increases

Deer is a food for the tiger. If all the deer populations from the forest are removed , then there will be no sufficient food available to the tigers. Some of the tigers will die due to starvation and their population will decrease. This will disturb the food chain in which tigers operate. The hungry tigers can come out of the forest in search of food and may kill domestic animals or human beings. Since the deer are herbivorous, there absence will increase the grassland area also. This on the whole will disturb the balance of ecosystem.

“pH has a great importance in our daily life". This can be explained by the following examples-
(i) Plants and animals are pH sensitive: Living organisms can survive only in narrow range of pH change.

(ii) Tooth decay: Change in pH of our mouth causes tooth decay. Tooth decay start when the pH of mouth is lower than 5.5. Tooth enamel gets corroded when the pH in mouth is below 5.5.

(iii) pH is our digestive system: (HCl) Hydrochloric acid is produced by our stomach that helps in the digestion of food. During digestion, if stomach produces too much acid, it will cause pain and irritation.

(iv) pH of the soil: Plants require a specific pH range for their normal growth.

Washing soda is synthesized through Solvay’s process. Solvay’s process involves the reaction of sodium chloride, ammonia and carbon dioxide in water. Carbon dioxide involved is produced through calcium carbonate and the calcium oxide left is used in recovering ammonia from ammonium chloride.

At first, sodium bicarbonate is obtained which is then converted to sodium carbonate on heating. Finally, washing soda is produced by recrystallization of sodium carbonate.

• NaCl + NH₃ + CO₂ + H₂O → NaHCO₃ + NH₄Cl
• 2 NaHCO₃ → Na₂CO₃ + H₂O + CO₂
• Na₂CO₃ + 10H₂O → Na₂CO₃.10H₂O

Washing soda is synthesized by the Solvay process.

The steps are given below:

1. Sodium chloride(NaCl), ammonia( NH3) and carbon dioxide( CO2) are taken in water to form sodium bicarbonate( NaHCO3).

2. Sodium bicarbonate is separated as it precipitates out from the solution as a solid. In presence of heat, it decomposes to form anhydrous sodium carbonate( soda ash).

3. Recrystallization of the sodium carbonate obtained by dissolving in water.

The process of formation of sodium carbonate is referred to as the Solvay process which is utilised to produce washing soda.

• Binary acids are certain molecular compounds in which hydrogen is bonded with a nonmetal.
• The names of binary acids begin with "hydro-" followed by the name of the other element, modified to end with "-ic."
• Binary acids are one of two classes of acids, the second being oxoacids (or oxyacids), which consist of hydrogen, oxygen, and a third element, which is often a non-metal.

Spherical mirrors

• Mirrors, whose reflecting surfaces are spherical, are called spherical mirrors.
• The reflecting surface of such mirrors can be considered to form a part of the surface of a sphere.
• A spherical mirror, whose reflecting surface is curved inwards, i.e. faces towards the centre of the sphere, is called a concave mirror.

The method of nourishment in Amoeba is holozoic.  

The different advances engaged with the procedure of nourishment are:  

• Ingestion: Amoeba ingests food with the assistance of its finger-like expansions, called pseudopodia. At the point when a food molecule approaches Amoeba, it structures pseudopodia around it and structures a food vacuole inside the Amoeba.  

• Processing: Various catalysts from the cytoplasm go into the food vacuole and separate them into straightforward dissolvable atoms.  

• Ingestion: The basic solvent food is consumed by cytoplasm of Amoeba from food vacuoles through the procedure of dispersion.  

• Osmosis: Amoeba cell acquires vitality from the retained food through breath. This vitality is used by Amoeba for its development and fix of the body.  

• Egestion: When a lot of undigested food gets gathered inside Amoeba, its cell film breaks and tosses out the undigested food.

Mitochondria are round "tube-like" organelles that provide energy to a cell in the form of ATP (Adenosine Triphosphate) for performing different chemical activities for the sustainance of life.
The mitochondria is also called powerhouse of the cell.

It is surrounded by two membranes.

• The outer membrane is porous wherea the inner membrane has deep folds that provides a large surface to perform the chemical reactions required for the generation of ATP.
• The inner membrane is compartmentalized into various cristae.
• The ground substance or space enclosed by inner membrane is called matrix.
• Mitochondria have their own DNA and ribosomes and are hence capable to produce some of their required proteins all by themselves.

Holozoic nutrition can be defined as a method of nutrition which involves the ingestion of some complex organic substances that may be in the solid or the liquid state. Here, certain parts of some plants or some animals or the organism as a whole are ingested. In this type of nutrition, the complex food is transferred into a specialized digestive system where it is broken down into small pieces in order to be absorbed. The 5 crucial stages that holozoic nutrition can be broken down into include: ingestion, digestion, absorption, assimilation, and egestion.

Nephrons are the microscopic structural and functional unit of the kidney. Nephrons are composed of a renal corpuscle and a renal tubule. The renal corpuscle consists of a tuft of capillaries called a glomerulus and an encompassing Bowman’s capsule.

Structure of a Nephrons:

• Nephrons are the basic filtering units of kidneys.
• Each kidney possesses large number of nephrons, approximately 1-1.5 million.
• The main components of the nephron are glomerulus, Bowman’s capsule, and a long renal tubule.

The chemical properties of acids 

• Acids change the colour of litmus from blue to red.
• They convert the colour of Methyl Orange from Orange/Yellow to Pink.
• Acids turn the pink colour of Phenolphthalein to colourless.
• Acids can conduct electricity.
• Some Acids are highly corrosive in nature which means that they corrode or rust metals.
• Acids tend to evolve hydrogen gas whilst reacting with an active metal such as Zn, Mg, etc.
• They produce H+ ions when mixed with water.
• Acids lose their acidity when mixed with a base.
• When equal amounts of acid and base are combined the process of neutralization occurs and salt and water is formed,
• The pH value of acid is from 0-6. Learn the concept of pH value here.
• Acids are sour in taste.
• Acids react with carbonates and hydrogen carbonates to form a salt, water, and carbon dioxide gas.
• Extremely active metals such as Potassium (K), Calcium (Ca), Sodium (Na), etc tend to explode when combined with acids.

In the chemical properties of  bases 

• They are bitter in taste.
• Bases lose their basicity when mixed with acids.
• Bases react with acids to form salt and water. This process is called Neutralisation Reaction(Read).
• They can conduct electricity.
• Bases feel slippery or soapy.
• Some bases are great conductors of electricity.
• Bases like sodium hydroxide, potassium hydroxide, etc are used as electrolytes.
• Alkalis are bases that produce hydroxyl ions (OH-) when mixed with water.
• Strong alkalis are highly corrosive in nature whereas other alkalis are mildly corrosive.

Acids

• Acids is defined as the one which produces hydrogen ions in water. For Example, Sulphuric Acid, Hydrochloric Acid etc.

• They give sour taste.

• Acids turn blue litmus to red. This is used as confirmation test for the presence of acid.

• When acids react with metals, gases are evolved.

Reactions with Acids

1. Reaction of Acid with Metal

Acid + Metal → Salt + Hydrogen gas

Mg + H2 SO4 → H2 + Mg SO4

2. Reaction of Acid with Carbonates

Na2 CO3 (s) + 2 HCl (aq) → 2NaCl (aq) + H2O(l) + CO2(g)

3. Reaction of Acid with Bicarbonates

NaHCO3 (s) + HCl (aq) → NaCl(aq) + H2O (l) + CO2 (g)

Similarity between Acids and Bases

• Both acids and base react with water. They produce ions in water

• Both acids and bases acts as electrolytes, so are good conductors of electricity.

• Both of them changes the colour of the litmus paper.

The Solvay Process is a continuous process using limestone (CaCO₃) to produce carbon dioxide (CO₂) which reacts with ammonia (NH₃) dissolved in brine (concentrated NaCl(aq)) to produce sodium carbonate.
The steps in the Solvay Process are:
i. Brine Purification
ii. Sodium Hydrogen Carbonate Formation
iii. Sodium Carbonate Formation iv. Ammonia Recovery
The solvay process uses salt (NaCl), limestone (CaCO₃​), ammonia(NH₃​) and coke(C) as the raw materials.

the raw materials in the Solvay process are the following:

• Sodium chloride (NaCl) or commonly known as purified brine
• Calcium carbonate (CaCO₃) or commonly known as limestone
• Coke
• Ammonia

The predominant removal mechanism in membrane filtration is straining, or size exclusion, where the pores are 0.01 micrometers or larger, so the process can theoretically achieve perfect efficiency regardless of parameters such as the solution's pressure and concentration.

Benefits of membrane filtration

• Lower overall production costs. Membrane filtration systems are often less expensive than many other alternative technologies. ...
• High flexibility. ...
• High end product quality.

•  Emulsification is the process of breaking down of the large fat globules into smaller globules and make them water soluble.
•  Emulsification of fats takes place in the gut with the help of the bile juice produced in liver.
•  It is necessary as it is difficult for the enzymes (lipases) to act on large fat globules. 
•  Emulsion of fats increases the efficiency of enzyme action to break down fats into fatty acids and glycerol which are easily absorbed through small intestines.

Male hormones, such as testosterone, are usually referred to collectively as androgens. The female hormones consist of two principal groups: the estrogens (e.g., estradiol) and the progestins (e.g., progesterone).

Hormones are natural substances produced in the body. They help to relay messages between cells and organs and affect many bodily functions. Everyone has what are considered “male” and “female” *** hormones.

Keep reading to learn more about the female *** hormones, how they fluctuate throughout your life, and signs of a hormonal imbalance.

Types of female *** hormones
The two main female *** hormones are estrogen and progesterone. Although testosterone is considered a male hormone, females also produce and need a small amount of this, too.

Estrogen
Estrogen is the major female hormone. The lion’s share comes from the ovaries, but small amounts are produced in the adrenal glands and fat cells. During pregnancy, the placenta also makes estrogen.

Estrogen plays a big role in reproductive and sexual development, including:

• puberty
• menstruation
• pregnancy
• menopause

Estrogen also affects the:

• brain
• cardiovascular system
• hair
• musculoskeletal system
• skin
• urinary tract

Progesterone
The ovaries produce the female *** hormone progesterone after ovulation. During pregnancy, the placenta also produces some.

The role of progesterone is to:

• prepare the lining of the uterus for a fertilized egg
• support pregnancy
• suppress estrogen production after ovulation

Testosterone

• Small amounts of testosterone come from the adrenal glands and ovaries. This hormone plays a role in several body functions, including:
• sexual desire
• regulation of the menstrual cycle
• bone and muscle strength