Transportation in Animals and Plants class 7 notes, mcq's and extra questions and answers
The NCERT Class 7 Science textbook covers the topic of transportation in animals and plants in Chapter 11. Here is a comprehensive summary of the chapter:
Introduction: Transportation is a vital process in living organisms that involves the movement of various substances, such as water, nutrients, gases, and wastes, from one part of the body to another. In this chapter, we will study the mechanism of transportation in animals and plants.
Transportation in Animals: The chapter begins by discussing the circulatory system in humans, which is responsible for the transportation of blood, oxygen, and nutrients. The circulatory system consists of the heart, blood vessels, and blood. The heart is the pumping organ that circulates the blood throughout the body. The blood vessels include arteries, veins, and capillaries, which transport the blood to different parts of the body. The blood contains various cells, such as red blood cells, white blood cells, and platelets, which have different functions. The red blood cells carry oxygen from the lungs to the tissues, while the white blood cells fight infections, and the platelets help in blood clotting.
The chapter then explains the different types of blood vessels and their functions. Arteries carry oxygen-rich blood from the heart to the body tissues, while veins carry oxygen-poor blood from the body tissues back to the heart. Capillaries are small blood vessels that connect arteries and veins and are responsible for the exchange of gases, nutrients, and wastes between the blood and the body tissues.
The chapter also discusses the respiratory and excretory systems in humans and how they contribute to the transportation of gases and wastes, respectively. The respiratory system involves the exchange of gases, such as oxygen and carbon dioxide, between the lungs and the blood. The excretory system eliminates waste products, such as urea and excess water, from the body.
Transportation in Plants: The chapter then moves on to the mechanism of transportation in plants. The transportation of water and nutrients in plants is essential for their survival and growth. The plant's vascular system consists of two types of tissues: xylem and phloem. Xylem is responsible for transporting water and minerals from the roots to the leaves, while phloem transports food from the leaves to other parts of the plant.
The chapter explains the structure and function of xylem and phloem tissues in detail. Xylem tissue consists of tracheids and vessels that transport water and minerals through the plant. Phloem tissue consists of sieve tubes and companion cells that transport food substances, such as sugars and amino acids, from the leaves to the rest of the plant.
The chapter then discusses the mechanism of water uptake by the roots through osmosis and the role of root hairs in increasing the surface area for absorption. It also explains the process of transpiration, which is the loss of water vapor from the leaves of plants, and how it helps in the transportation of water and nutrients.
The chapter also explains the importance of mineral ions, such as nitrogen, phosphorus, and potassium, in plant growth and development. It discusses the process of nitrogen fixation, which is the conversion of atmospheric nitrogen into a usable form by certain bacteria.
Conclusion: In conclusion, the chapter provides a comprehensive understanding of the mechanism of transportation in animals and plants. It emphasizes the importance of a healthy circulatory system in humans and the role of xylem and phloem tissues in the transportation of water, nutrients, and food substances in plants. It also highlights the significance of maintaining a balanced diet and regular exercise for a healthy circulatory system.
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