Biology (Part-II) (UPSC)

• Aerobic Respiration: It is the process of cellular respiration that takes place in the presence of oxygen gas to produce energy from food. This type of respiration is common in most of the plants and animals, birds, humans, and other mammals. In this process, water and carbon dioxide are produced as end products.
• Anaerobic Respiration: It is a process which takes place in the absence of oxygen gas. In this process, the energy is obtained by the breakdown of glucose in the absence of oxygen. One of the best examples of anaerobic respiration is the process of fermentation in yeast.

• An unsaturated fat is a fatty acid in which there is at least one double bond within the fatty acid chain.
• Where double bonds are formed, hydrogen atoms are eliminated.
• In cellular metabolism, unsaturated fat molecules contain somewhat less energy (i.e., fewer calories) than an equivalent amount of saturated fat.
• The greater the degree of unsaturation in a fatty acid (i.e., the more double bonds in the fatty acid) the more vulnerable it is to rancidity (lipid oxidation or rusting of fats).
• Antioxidants can protect unsaturated fat from lipid oxidation.

Haemophilia is a sex-linked recessive disorder. Clotting of blood is abnormally delayed that even a simple or small cut will result non stop bleeding in affected individual.
Haemophilia

• It is a medical condition, mostly inherited, in which the ability of blood to clot is severely reduced.
• This disease is caused by a mutation in one of the genes, that provides instructions for making the clotting factor proteins needed to form a blood clot.
• This change or mutation can prevent the clotting protein from working properly or to be missing altogether. These genes are located on the X chromosome.
• Men are more vulnerable to haemophilia than women. It is a rare disease where in about 1 in 10,000 people are born with it.

Generally blindness is caused by the dryness and hardness of cornea. Cornea is a clear layer which helps passing of light. It is an outer layer and can be transferred from one person to another.
The human eye is a sophisticated organ with various components working together to enable vision. Its main structures include:
Cornea: The transparent, dome-shaped outer layer that refracts and focuses light entering the eye.
Iris: The colored part of the eye containing muscles that regulate the size of the pupil to control the amount of light entering.
Pupil: The central opening in the iris that allows light to pass into the eye.
Lens: A flexible, transparent structure that adjusts its shape to focus light onto the retina for clear vision.
Retina: The light-sensitive layer at the back of the eye, containing photoreceptor cells (rods for dim light and cones for color vision) that convert light into electrical signals.
Optic Nerve: Transmits visual signals from the retina to the brain for interpretation.
Sclera: The white, tough outer covering that protects the eye and provides structure.
Aqueous and Vitreous Humors: Fluids maintaining eye shape and nourishing internal structures.

These components work in harmony to produce sharp, detailed, and colorful images.

• It is a medical condition, mostly inherited, in which the ability of blood to clot is severely reduced.
• This disease is caused by a mutation in one of the genes, that provides instructions for making the clotting factor proteins needed to form a blood clot.
• This change or mutation can prevent the clotting protein from working properly or to be missing altogether. These genes are located on the X chromosome.
• Men are more vulnerable to haemophilia than women. It is a rare disease where in about 1 in 10,000 people are born with it.