CBSE Cbse Class 7 Science Revision Notes Chapter 11

CBSE Class 7 Science Revision Notes Chapter 11 – Transportation in Animals and Plants

Extramarks offers Revision Notes for Class 7 Science Chapter 11 created by subject matter experts. Chapter 11 of Class 7 Science discusses how various parts of plants and human organs transport important substances and nutrients throughout their bodies. It also discusses excretion in both animals and humans. Students can prepare for the exams by visiting the Extramarks website for CBSE Class 7 Science Chapter 11 Notes. These notes will help them understand the overall concept of the topic and effectively revise the entire syllabus to score more marks in the exams.

Revision Notes for CBSE Class 7 Science Chapter 11

Access Class 7 Science Chapter 11 – Transportation in Animals and Plants Notes

Circulatory System

Blood, blood vessels, and the heart comprise the circulatory system.

Our blood transports oxygen, minerals, and nutrients to all parts of the body.

Blood:

Blood is a red fluid that is coloured by the presence of haemoglobin.

Haemoglobin is in charge of transporting oxygen throughout the body.

There are three types of cells in the blood.

• Red Blood Cells (RBC): They transport oxygen from the lungs to various parts of the body and carbon dioxide from various parts of the body to the lungs.
• White Blood Cells (WBC): These cells provide immunity against foreign microorganisms that cause disease and infection.
• Platelets: They form a shield-like structure at the site of injury to stop bleeding; this is known as blood clotting.

Plasma: Blood contains both cells and fluid, the latter of which is known as plasma.

Blood Vessels:

Blood vessels are the pipe-like structures through which blood flows.

Blood vessels are classified into three types:

• Arteries: These vessels transport oxygenated blood from the heart to the body’s tissues.

• Veins: These vessels transport deoxygenated blood from the body’s tissues to the heart.

• Capillaries: This serves as a binding agent for arteries and veins.

Heart:

It is a fist-sized muscular organ located on the left side of the chest.

It is the most vital organ in our bodies because it aids in the transport of oxygen and other nutrients through the blood.

The heart is separated into four chambers to prevent the mixing of oxygenated and deoxygenated blood.

The atria, which is further divided into left and right atriums, are the top two chambers of the heart.

The ventricles, or the lower two chambers of the heart, have left and right ventricles.

A heartbeat is the contraction and relaxation of the muscles that make up the walls of the chambers of the heart.

Excretion in Animals

The elimination of undesired or waste material from the body is known as excretion.

Carbon dioxide is expelled from an animal’s body by exhalation.

Undigested food is removed from an animal’s body by egestion.

Excretory System in Humans

The excretory system is the system responsible for removing waste from the body.

It is made up of the kidney, ureter, urinary tract, and urethra.

• Kidney: This bean-shaped organ’s main function is to filter blood and remove waste material in the form of urine.

• Urinary Bladder: It stores urine to prevent frequent urination.

• Ureter: It is a pipe-like structure that connects the kidney and the urinary bladder and allows urine to flow from the kidney to the bladder.

• Urethra: This is a urinary opening that allows urine to exit our bodies.

Transportation in Plant

Plants requires water, nutrients, and carbon dioxide to survive.

Photosynthesis, which involves the combination of water and carbon dioxide, is used by leaves to prepare food.

Minerals and water are absorbed by plant roots from the soil. 

Plants use vascular tissues to transport water, minerals, and food.

Vascular tissues are pipe-like structures in plants that allow water, minerals, and food to be transported. It is linked from the leaves to the roots.

Transportation in Animals and Plants Class 7 Science Notes

Transportation in Humans

Circulatory System

The circulatory system is the mechanism that carries blood out from the heart and distributes it throughout the body before bringing it back. The following elements make up the human circulatory system:

• Heart: The heart is a highly muscular structure in the chest cavity.
• Blood Vessels: Arteries, veins, and capillaries are all types of blood vessels.
• Blood: A connective tissue fluid that circulates throughout the body.

Heart

The heart is the most vital and sensitive organ in the human body. It beats continuously to act as a pump for blood transport. It is positioned in the chest cavity, slightly to the left and is the size of a human fist. The human heart has four chambers, the upper two of which are known as atria and the lower ones as ventricles. The wall between the chambers prevents oxygen-rich blood from mixing with carbon dioxide-rich blood.

The left side of the heart receives oxygen-rich blood from the lungs and distributes it to all parts of the body, while the right side receives carbon dioxide-rich blood from all parts of the body and sends it to the lungs, which purifies the blood. 

• Heartbeat: A heartbeat is a rhythmic contraction followed by relaxation of the heart muscles.
• Pulse: A pulse is the throbbing of an artery caused by blood flow pressure.
• Stethoscope: The stethoscope is a device that amplifies the sound of the heart.

Blood

It is a connective tissue that is fluid. The heart is in charge of circulating blood throughout the body. The fluid component is known as plasma. Plasma is made up of various suspended cells. 

• Red Blood Cells (RBCs): It contains haemoglobin, a red pigment that gives blood its characteristic red colour. This pigment binds to oxygen and transports it to all blood cells.
• White Blood Cells (WBCs): These cells protect us by fighting disease-causing germs.
• Platelets: Platelets aid in the clotting of blood at the site of injury.

Functions of Blood

• The primary function of blood is to transport oxygen from the lungs to all parts of the body and carbon dioxide back to the lungs for purification.
• It transports digested food throughout the body.
• Blood keeps the body temperature stable.
• It also does the job of transporting waste to the kidneys for excretion.

Blood Vessels

Blood vessels are classified into three types: arteries, veins, and capillaries. The arteries and veins work in opposition to one another, while the capillaries serve as a connecting link.

Capillaries

Capillaries are very thin vessels that connect arteries and veins. Through the walls of capillaries, oxygen and digested food, carbon dioxide, and other wastes are exchanged between the blood and the surrounding cells.

Excretion in Animals and Humans

Excretion is the process of eliminating metabolic waste products from the body.

Excretion in Animals

There are no special excretory organs in organisms such as amoeba, hydra, sponges, and so on. Waste products are excreted through the general body surface via diffusion.

Cellular waste, such as ammonia, is dissolved directly in water in aquatic animals such as fish.

Uric acid is excreted by birds, reptiles, and insects as nitrogenous waste.

Other land mammals excrete urea as their primary nitrogenous waste.

Human Excretory System

In the human excretory system, there are two kidneys, one on each side just below the stomach. Because they filter only unwanted substances from the blood, kidneys are also known as magic filters.

The tube-like uterus transports urine from the kidneys to the urinary bladder. Urine is stored in the urinary bladder and excreted through the urethra, which is a urinary opening.

An adult human passes about 1-1.8 litres of urine per day.

When the kidneys stop working properly, wastes begin to accumulate in the blood. This is extremely hazardous to humans. A technique known as dialysis is used to filter blood on a regular basis.

Sweat is the moisture that escapes from the skin’s pores. Sweat glands in the skin produce it. Sweating flushes the body of water and salts.

Transportation in Plants

The vascular system in plants transports water, minerals, food, and waste from one part of the plant to another for the plant to perform various functions. It is composed of two types of tubes known as xylem and phloem.

• A tissue is a group of cells in an organism that performs a specific function. Plants’ vascular tissue for transporting water and minerals is the xylem, while the phloem transports organic products of photosynthesis.
• The xylem and phloem are both arranged in a compact structure known as vascular bundles.

Xylem

The xylem forms a network of channels that aid in the upward movement of water and dissolved minerals from the roots to the leaves via the stem. They are typically composed of dead cells.

Phloem

The phloem contains vessels known as sieve tubes that transport food downward, from the leaves to all parts of the plant. They are typically composed of living cells.

Transportation Water and Minerals

Plant roots have tiny outgrowths called root hairs that allow water and dissolved mineral salts to enter. The root hair increases the surface area available for water and mineral salt absorption. Osmosis is the process by which roots absorb water from the soil.

Osmosis is the passage of water across a cell membrane over short distances from a higher concentration to a lower concentration.

Water and mineral salts are constantly absorbed by the root cells from the soil. Some of the excess water absorbed by roots is lost as water vapour because of transpiration through stomata in the leaves. This creates a suction pull, causing water to rise to great heights in tall trees. The plant is also cooled by transpiration.

Important Points to Remember

Food, oxygen, and waste products, among other things, must be transported from one part of the body to the other in living organisms.

Plants have xylem (water and mineral) and phloem as their transport system (food).

Material transport in humans takes place via the blood.

Blood is pumped by the heart and circulated throughout the body via blood vessels.

Blood is made up of liquid plasma and three types of blood cells floating in it: red blood cells, white blood cells, and platelets.

Blood is transported by three types of blood vessels: arteries, veins, and capillaries.

The human heart is divided into four chambers: the upper two are known as the atria or auricles, and the lower two are known as the ventricles.

A heartbeat is produced by the contraction of the heart muscles. This is known as a pulse, and it is felt as a throbbing in the artery near the wrist.

The removal of metabolic wastes from the body is referred to as excretion.

Humans excrete through their lungs, skin, and kidneys.

The kidneys filter waste from the blood, which is then excreted from the body as urine.