Railway Science (Biology – Miscellaneous)

Hormone and enzymes are made up of proteins and the formation of any particular protein is controlled by a particular gene. Genes consist of deoxyribonucleic acid (DNA), DNA contains the code, or blueprint, used to synthesize a protein.

Biological magnification: Process of accumulation of certain chemicals in living organisms to a concentration higher than that occurring in the inorganic, non-living environment.
Contaminants: mercury, arsenic, and pesticides such as polychlorinated biphenyls and DDT. Causes: Agricultural pesticides, insecticides, fertilizers and fungicides; Manures and biosolids; Industrial wastes; Mining Activities in the Ocean.
Effects: Humans more prone to cancer, kidney problems, liver failure, birth defects, respiratory disorders, and heart diseases, Cyanide destroy the coral reefs, Disruption of Food Chain.

Emulsification of fats - Process of breaking down the complex fat molecules converted into smaller fat molecules by the Bile juice secreted by the liver that will be easier to digest with the help of enzymes. Final products - Fatty acids and glycerol (easily absorbed by the small intestine).

Proteins are essential bio-molecules that actively participate in many important and fundamental aspects of life. Nitrogen is used for protein synthesis and an essential constituent of amino acids. The main forms of inorganic nitrogen in the soil are nitrate and ammonium, which plants absorb from roots.

Plasma is the liquid component of the blood that helps in the transportation of various hormones, nutrients, and metabolic wastes.
Platelets (Thrombocytes) are small, colorless cell fragments in our blood that form clots and stop or prevent bleeding.
Platelets are made in our bone marrow, the sponge-like tissue inside our bones. Bone marrow contains stem cells that develop into red blood cells, white blood cells, and platelets.
A normal platelet count ranges from 150,000 to 450,000 platelets per microliter of blood. WBC - White blood cells (leukocytes) responsible for protecting and fighting against invading pathogens.
RBC - Red blood cells (Erythrocytes) contain a protein called hemoglobin, which carries oxygen from the lungs to all parts of the body. Each red blood cell only lives for about 120 days.

The respiratory pigment is present in the Red blood cells, that is Hemoglobin. Cellular respiration is the process through which cells get the energy to perform functions.
Types of cellular respiration - Aerobic {(in presence of oxygen) performed by multicellular organisms like humans, birds} and Anaerobic {(in absence of oxygen) performed by yeast, bacteria}.
Pyruvate Oxidation: A biochemical reaction that involves the oxidation of pyruvate to create Acetyl Coenzyme A (C₂₃H₃₈N₇O₁₇P₃S).

Acids and their Natural resources: Tomato - oxalic acid, Ant sting - Methanoic acid (Formic acid), Tamarind -Tartaric acid. Orange - Citric acid.

New buds are formed in this season. These buds need more energy to grow than other parts of the plant. This energy comes from the sugar stored in the root or stem tissue to the buds by the phloem.
Xylem distributes water and minerals from the roots to the leaves. Phloem carries food downward from the leaves to the roots.

The fluid in the cells is usually a thin, watery sap that freezes readily. Cells cannot survive winter where temperatures fall below freezing. Deciduous Trees - that lose all of their leaves for part of the year. Example - Maples, birch, oak, hickory, dogwood, and redbud (losing their leaves during the winter).

Bacteria present in the mouth produce acids by degradation of sugar and food particles remaining in the mouth after eating. This acid lowers the pH in the mouth. Tooth decay starts when the pH of the mouth is lower than 5.5. Tooth enamel made up of calcium phosphate is the hardest substance in the body.