Explain the different types of Transport.
Answers
★ TYPES OF TRANSPORT:-
→ Passive transport:- It is the movement of molecules across the membrane along the concentration gradient i.e., from higher concentration to the lower without the expenditure of energy. It is 2 types:-
o Simple diffusion:- It is the movement of neutrasolutes across the membrane.
o Osmosis:- It is the movement of water by diffusion across the membranc.
o As the polar molecules cannot pass through the non-polar lipid bilayer, they require a carrier protein of the membrane to facilitate their transport.
→ Active transport:- It is the movement of molecules across the membrane against the concentration gradient i.e. from lower to the higher concentration with the expenditure of energy, E.g. Na+ and K+ pump.
Answer:
Roadways
The most commonly used means of transport, especially for short distances, are roads. They can be metalled and unmetalled. Roads have also been built in terrains like deserts, forests and even high mountains. Manali-Leh highway in the Himlayan Mountains is one of the highest roadways in the world. Roads built underground are called subways/under paths. Flyovers are built over raised structures.
Railways
The invention of the steam engine and the Industrial Revolution helped in speedy development of rail transport. Diesel and electric engines have largely replaced the steam engines. The railway network is well developed over the plain areas. Advanced technological skills have enabled laying of railway lines in difficult mountain terrains also. The Indian railway network is well developed. It is the largest in Asia.
Waterways
Waterways are the cheapest for carrying heavy and bulky goods over long distances. They are mainly of two types – inland waterways and sea routes. Navigable rivers and lakes are used as inland waterways. Some of the important inland waterways are the Ganga-Brahmaputra river system, the Great Lakes in North America and the river Nile in Africa.
Sea routes and oceanic routes are mostly used for transporting merchandise and goods from one country to another. These routes are connected with the ports. Some of the important ports of the world are Singapore and Mumbai in Asia, New York, Los Angeles in North America, Rio de Janerio in South America, Durban and Cape Town in Africa, Sydney in Australia, London and Rotterdam in Europe.
Airways
Airways is the fastest way of transport developed in the early twentieth century. It is also the most expensive due to the high cost of fuels. Air traffic is adversely affected by bad weather like fog and storms. It is the only mode of transport to reach the most remote and distant areas, especially where there are no roads and railways. Helicopters are extremely useful in most inaccessible areas and in times of calamities for rescuing people and distributing food, water, clothes and medicines.