Biology (Part-III) (Railway)

• Transcription is performed by enzymes called RNA polymerases, which link nucleotides to form an RNA strand (using a DNA strand as a template).

• Autotroph's that in the food chain, means they create their own nutrients and energy.

• External respiration involves both bringing air into the lungs (inhalation) and releasing air to the atmosphere (exhalation).

• During internal respiration. oxygen and carbon dioxide are exchanged  between the cells and blood vessels,

• Vertebrates such as mammals, fish, birds, reptiles and amphibians all have a backbone.

• It is a long pipe-like structure arising from the medulla oblongata, part of the brain consisting of a collection of nerve fibres, running through the vertebral column of the backbone.

• It is segmented with a pair of roots (dorsal and ventral roots) consisting of nerve fibres joining to form the spinal nerves.

• They are heterotrophic (obtain food from external sources) and utilize oxygen for energy catabolism.

• Biotic describes a living component of an ecosystem: for example organisms, such as plants and animals.

• Boron, germanium, silicon. antimony, arsenic, and tellurium are the six most widely recognized metalloids.