Railway Science (Biology – Cell : Basic Unit of Life) (Part-II)

Ribosome - It is responsible for protein synthesis, and their attachment to the RER allows for the production of proteins. Mitochondria (Powerhouse of cell) - It is membrane-bound organelles present in the cytoplasm of all eukaryotic cells that produce ATP (Adenosine triphosphate).
Centrosomes - It is involved in the process of cell division. Nucleus (largest cell organelle) - It contains genes and controls the activities of the cell. Cell was discovered by Robert Hooke in 1665 and the first living cell was observed by Leeuwenhoek in 1674.

Ionizing radiation : Induces direct DNA damage and indirect damage through the radiolysis of water. Benzene vapor - Heavier than air and may sink into low-lying areas. It can cause irritation in the respiratory tract, skin and eyes, causing anemia and leukemia.
Chlorinated water - Used to kill parasites, bacteria, and viruses. Chloroform (CHCl₃) - A colorless liquid that quickly evaporates into gas and can harm eyes, skin, liver, kidneys, and nervous system.

Cells of cork are dead and compactly arranged without any intercellular spaces. Cutin and suberin are complex polymers present in plant cell walls. These are the polyesters of hydroxy fatty acids.
These occur in plant cells with associated waxes comprising the hydrocarbons chain. Chitin is present in the exoskeleton of insects, cell walls of fungi and certain hard structures in invertebrates and some fishes.

The breakdown of pyruvate gives carbon dioxide, water and energy. Mitochondria have two membrane coverings. The outer membrane is porous while the inner membrane is deeply folded.
Lysosomes (Suicide bags): Lysosomes are single membrane structures containing enzymes for digestion of all types of macromolecules.
Vacuoles are storage sacs for solid or liquid contents. Vacuoles are small sized in animal cells while plant cells have very large vacuoles

Its primary role is to protect the underlying layers. It helps in the prevention of water loss through transpiration and helps the desert plants to retain moisture for a long period of time. It is a waxy water-repellent substance in the cuticle of plants, consisting of highly polymerized esters of fatty acids.

Genes are the chemical codes that control everything about how the body works, how it is made, and what it looks like. Chromosomes are composed of DNA wrapped tightly by proteins called histones. Lysosomes are single membrane structures containing enzymes for digestion of all types of macromolecules.

During protein synthesis, mRNA (messenger RNA) is formed from a process known as transcription. Transcription occurs in the nucleus of a cell, where the DNA molecule serves as a template for synthesizing mRNA.
This process involves the enzyme RNA polymerase, which binds to the DNA and constructs a complementary mRNA molecule by adding nucleotides according to the sequence of the DNA template.

Chromosomes are thread-like structures that contain the genetic material of an organism. Number of chromosomes fixed in a species, present in homologous pairs (both chromosomes of a pair bearing same genes, but not necessarily same alleles).
Hence, the fixed member is termed diploid and designated as 2n (n = haploid). In humans 2n = 46, out of these 44 are termed autosomes and X and Y as sex chromosomes.

Glucose is broken down into pyruvate and energy is released in the form of ATP in the cytoplasm. The breakdown of Pyruvate to give Carbon dioxide, energy and water which takes place in the presence of Oxygen, termed as aerobic respiration.

Genes carry Genetic information from generation to generation that determines an individual's traits. The genotype is a set of genes in the DNA which are responsible for the unique traits or characteristics. Whereas the phenotype is the physical appearance or characteristic of the organism. RNA is a ribonucleic acid that helps in the synthesis of proteins in our body.