Buy BOOKS at Discounted Price

Transportation In Aminals And Plants

Class 7th Science CBSE Solution

Exercise
Question 1.

Find out about the blood groups and their importance.


Answer:

Carl Landsteiner (1900) discovered that there are two types of antigens present on the plasma membrane of the RBC. These are antigen A and antigen B. These are also called corpuscle factors. There are also two types of antibodies present in the plasma. These are antibody A (Anti-A) and antibody B (Anti-B). These are also called plasma factors. The blood is classified into four groups on the basis of the presence or absence of these antigens. These groups are A, B, AB and O. This system of classification of blood is called: ‘ABO’ system.


The following table shows the types of blood groups and their antigens and antibodies:



Along with the A and B antigens or antibodies many people have another factor called the Rh factor. This is an antigen first found in Rhesus monkey (hence, called the Rh factor). People whose red blood cells contain the Rh antigen are said to be Rh positive (Rh+). People who lack it are called Rh negative (Rh-). A person with Rh blood does not have Rh antibody (which destroys Rh antigen) naturally. But, as and when an Rh antigen enters the blood, it develops and destroys the antigen.


If a person with blood group A has Rh antigen, his/her blood is said to be A+ (A positive). Similarly, if a person’s blood group is B and he/she do not have Rh antigen, then his/her blood group is B-(B negative). So, we have eight blood groups:


A+,B+,AB+,O+,A-,B-,AB- and O-


The following table gives a complete list of blood group matching:




Question 2.

Match structures; given in Column I with functions given in Column II.


Answer:

i. The evaporation of water from the stomata present on the surface of the leaves is called transpiration.


ii. The xylem tissues join together and forms a continuous network of channels that connects roots to the leaves through the stem and branches and thus transports water to all parts of the plant.


iii. The root hair increases the surface area of the root for the absorption of water and mineral nutrients dissolved in water.


iv. Phloem tissues join together and form long tube which transport food from leaves to other parts of the plant body.



Question 3.

Fill in the blanks.

i. The blood from the heart is transported to all parts of the body by the _________.

ii. Hemoglobin in present in ______ cells.

iii. Arteries and veins are joined by a network of _____.

iv. The rhythmic expansion and contraction of the heart is called_____.

v. The main excretory product in human beings is ______.

vi. Sweat contains water and ________.

vii. Kidneys eliminate the waste materials in the liquid form called______.

viii. Water reaches great heights in the trees because of suction pull caused by _______.


Answer:

i. Arteries.


These are thick blood vessel which transport blood from heart to all parts of the body.


ii. red blood.


Red blood cells(RBC) contain a red pigment called hemoglobin. Hemoglobin bind with oxygen and transports it to all the parts of the body and ultimately to all the cells.


iii. Capillaries.


Arteries and veins are joined by a network of capillaries.


iv. Heartbeat.


One complete contraction and relaxation of the heart is called a heart-beat. The usual heart beat rate at rest is 72 times /minute.)


v. urea


Urea is the main excretory product in human beings. The urine consists of 95% water and 2.5% urea


vi. Salts.


Sweat contain water and salts.


vii. Urine.


An adult human being normally passes about 1–1.8 L of urine in 24 hours, and the urine consists of 95% water, 2.5 % urea and 2.5% other waste products.


viii. Transpiration.


The evaporation of water from the leaves of the plants is called transpiration.



Question 4.

When a person suffers from chest pain, the doctor immediately takes an ECG. Visit a doctor and get information about ECG. You may even look up an encyclopedia or the internet.


Answer:

An electrocardiogram (ECG or EKG abbreviated from the German Elecktrokardiogramm) is a graphic produced by an electrocardiograph, which records the electrical activity of the heart over time. ‘Analysis’ of the various waves and normal vectors of depolarization and depolarization yields important diagnostic information.


•It guides therapy and risk stratification for heart patients


•It helps detect electrolyte disturbances. It allows for the detection of conduction abnormalities.


•It is used as a screening tool for ischemic heart disease during a cardiac stress test.


•It is occasionally helpful with non-cardiac.


In 1856 Kollicker and Mueller discovered the electrical activity of the heart when a frog sciatic nerve/gastrocenemius preparation fell onto an isolated frog heart and both muscles contracted synchronously. Alexander Muirhead attached wires to a feverish patients’ wrist to obtain a record of the patient’s heartbeat, while studying for his DSc (in electricity) in 1872 at St. Bartholomew’s Hospital. This activity was directly recorded and visualized using a Lippmann capillary electrometer by the British physiologist John Burdon Sanderson. The first to systematically approach the heart from an electrical point-of-view was Augustus Waller, working in St. Mary’s Hospital in Paddington, London. His electrocardiograph machine consisted of a Lippmann capillary electrometer fixed to a projector. The trace from the heartbeat was projected onto a photographic plate which was itself fixed to a toy train. This allowed a heartbeat to be recorded in real time. In 1911 he still saw little clinical application for his work.


The breakthrough came when Willem Einthoven, working Leiden. The Netherlands used the string galvanometer invented by him in 1901, which was much more sensitive than the capillary electrometer that Waller used. Einthoven assigned the letters P, Q.R, S and T to the various deflections and described the electrocardiographic features of a number of cardiovascular disorders. In 1924, he was awarded the Noble Prize in Medicine for his discovery.



Question 5.

Choose the correct options:

In plants, water is transported through

i. Xylem ii. Phloem

iii. Stomata iv. Root hair

Correct


Answer:

Xylem carries water and dissolved minerals in upward direction from roots to the leaves of plant.


Question 6.

Choose the correct options:

Water absorption through roots can be increased by keeping the plants

i. in the shade ii. in dim light

iii. Under the fan iv. Covered with a polythene bag.

Correct


Answer:

When we place a plant place under the fan, the speed of air flow is very high. Transpiration will take place in the presence of high air flow through the stomata. The rate of transpiration increases during windy condition


Question 7.

Why is transport of materials necessary in a plant or animal? Explain.


Answer:

The transport system is necessary for a plant or an animal because of the following reasons:-

1) In plants, water and dissolved minerals are transported from roots to leaves by xylem whereas prepared food is transported from leaves to all parts of the plant by phloem. If there were no transport system in the plant, leaves would not get water for photosynthesis and thus, they would die.

2) In the case of animals, food and water are transported to all parts of the body so; they can generate energy and grow cells. Similarly, waste products produced by the cells of the body are transported to their excretory organs so that they can be excreted. If there were no transported system in animals, they would not be able to get energy or get rid of the waste. Thus, they would die.


Question 8.

What will happen if there are no platelets in the blood?


Answer:

The main function of platelets is to prevent bleeding. Platelets helps in the coagulation of blood (clotting of blood) in a cut or wound. If there are no platelets in the blood, it will continue to flow out from the wound and ultimately the person will die


Question 9.

What are stomata? Give two functions of stomata.


Answer:

Stomata are tiny pores present on the surface of the leaves. The functions of stomata:

(i) gaseous exchange for respiration


(ii) removal of excess water by transpiration.


The following picture shows the opening and closing of stoma to allow the intake of carbon dioxide and the release of oxygen.



Question 10.

Does transpiration serve any useful function in the plants? Explain.


Answer:

The evaporation of water from the leaves of the plants is called transpiration. The evaporation of water from leaves generates a suction pull which can pull water to great heights in the tall trees.Thus transpiration serves as very important function in plants


Question 11.

What are the components of blood?


Answer:

Blood is a red colour liquid which circulates in our body. The main components of blood are:


•Plasma


•RBC (Red blood cells)


•WBC (White blood cells), and


•Platelets


The following image shows the components of blood:




Question 12.

Why is blood needed by all the parts of a body?


Answer:

Blood carries digested food and oxygen to all parts of body. It also carries away the waste products from different body parts. It is serves as a connective tissue.


Question 13.

What makes the blood look red?


Answer:

Blood is red in colour because it contains a pigment called hemoglobin in its red cells (RBC).



Question 14.

Describe the function of the heart.


Answer:

The heart is an organ act as a pump for the transport of blood and various other substances.

The human heart is divided into four chambers. The upper two chambers are called right and left atrium and the lower two chambers are called the right and left ventricles.

The right atrium receives the blood rich in carbon dioxide from the body. Blood from right atrium enters the right ventricle, which contracts and pumps the blood to the lungs.

On the other hand, blood from the lungs returns to the left atrium. From the left atrium, blood enters the left ventricle.

Left ventricle contracts and pumps the blood to all parts of the body. Hence, the rhythmic contraction and expansion of various chambers of the heart maintain the transport of oxygen to all parts of the body.



Question 15.

Why is it necessary to excrete waste products?


Answer:

All the cells of our body produce waste of some kind. These waste products cannot be allowed to stay inside the body because they will accumulate and cause problems. Sometimes, it can even be fatal. Therefore, the waste products need to be removed from the body. This process of elimination is known as excretion.


Question 16.

Draw a diagram of the human excretory system and label the various parts.


Answer:

The human respiratory system has the following parts:


i. Kidney: The kidneys filter the wastes which is flushed out of the body as urine and excreta.


ii. Ureter: The ureters transfer liquid waste from the kidneys into the urinary bladder.


iii. Urinary Bladder: The urinary bladder stores the urine until it is finally discharged from the body.


iv. Urethra: The urethra is a carrier of semen (in males) as well as urine for the ultimate discharge out of the body.


v. Urinary Opening: The urine is exits out of the body from this opening.



Fig. Excretory System