What is Transportation in Animals and Plants Class 7: Complete Guide

Definition and Importance of Transportation in Animals and Plants

Transportation in animals and plants refers to the movement of essential substances such as water, minerals, food, and gases within their bodies. This process is crucial because it helps cells receive nutrients and oxygen and removes waste products. Without transportation, living organisms cannot survive or grow.

In plants, transportation helps distribute water from roots to leaves and food from leaves to other parts. In animals, transportation ensures oxygen reaches cells and nutrients from food are carried to different tissues. Understanding this process is fundamental for Class 7 students studying NCERT Science.

How Transportation Happens in Plants: Xylem and Phloem

Plants have two main types of tissues for transportation:

• Xylem: Transports water and dissolved minerals from roots to leaves.
• Phloem: Transports food (mainly sugars) from leaves to other parts of the plant.

Xylem Transport

Water absorption occurs in roots and moves upward through xylem vessels by capillary action and transpiration pull.

Phloem Transport

Food produced by photosynthesis in leaves moves through phloem to growing parts and storage organs.

This dual transport system ensures plants get the water and nutrients needed for survival and growth.

Transportation in Animals: Circulatory System Overview

Animals have a circulatory system that transports oxygen, nutrients, hormones, and waste products throughout the body.

Components of Circulatory System

• Heart: Pumps blood.
• Blood: Carries oxygen, nutrients, and waste.
• Blood vessels: Arteries, veins, and capillaries carry blood to and from body parts.

How It Works

The heart pumps oxygen-rich blood through arteries to body cells. Cells use oxygen and nutrients, then produce waste like carbon dioxide. Blood carries waste back to lungs and kidneys for removal.

This system keeps animal cells healthy and supports activities like movement and growth.

Comparison Between Transportation in Plants and Animals

Understanding the differences and similarities between transportation in plants and animals helps clarify their unique adaptations.

Both systems ensure survival by distributing vital substances efficiently.

How Water and Food are Transported in Plants

Water transport in plants starts at the roots, where water is absorbed from the soil. It moves upward through the xylem vessels to the leaves. This movement is helped by:

• Root pressure: Pushes water upward.
• Capillary action: Water climbs narrow tubes.
• Transpiration pull: Water evaporates from leaves, pulling water upward.

Food transport occurs in the phloem. Sugars made in leaves during photosynthesis move to other parts like roots and fruits. This process is called translocation and requires energy.

Worked Example

If a plant loses 5 ml of water by transpiration, approximately 5 ml of water is pulled up through xylem to replace it, maintaining balance.

How Oxygen and Nutrients are Transported in Animals

In animals, oxygen from the lungs enters the blood and binds to haemoglobin in red blood cells. The heart pumps this oxygen-rich blood through arteries to body tissues. Nutrients absorbed from food in the digestive system also enter the blood.

Waste products like carbon dioxide are carried back to lungs and kidneys for removal.

Simple Formula for Blood Circulation

$$ \text{Heart} \rightarrow \text{Arteries} \rightarrow \text{Capillaries} \rightarrow \text{Veins} \rightarrow \text{Heart} $$

This continuous loop ensures all body parts get oxygen and nutrients and waste is removed efficiently.