9th Biology Chapter # 9 All Punjab Board Papers | 5 Years old Board Papers Short questions | Repeated Short questions in all Board Papers

 CHAPTER No. 9

1.                 What are conducting "tissues" for food in plants? Write their composition also.

Ans:    Phloem tissues are the conducting tissues for food in plants.

            These tissues are composed of sieve tube cell and companion cells.

2.                 What is role of xylem and phloem tissues in plant's life?

Ans:    Xylem tissue is responsible for the transport of water and the dissolved substances from roots to aerial parts. The phloem tissue is responsible for the conduction of dissolved organic matter between different parts of plants body. It contains vessel elements and tracheas.

3.                 Write the function of root in plant.

Ans:    The root provides the support to the plant. The root hairs present at the surface of the root provide large surface area for absorption of water and minerals from root.

4.                 Write down two characteristics of root hairs.     Or        Function of root.

Ans:    Root hairs provides large surface area for absorption of water and minerals.

They grow out into the spaces between soil particles where they are in direct contact with water to absorb the water and salts by osmosis, diffusion and active transport.

5.                                    What role root hair play in life of plants?

Ans:       Root hairs are absorbs the water from soil and then transfer it through xylem tissue.

6.                 What do you meant by transpiration? Explain it.                       

Ans:    Transpiration is the loss of water from plant surface through evaporation. This loss may occur through stomatal in leaves through the cuticle present on leaf epidermis and through special opening called lenticels present in the stem of some plant. Most of transpiration occurs through stomata and is called stomatal transpiration.

7.                 What do you meant by stomal transpiration? Explain it briefly.

Ans:    If the transpiration occurs through the stomata is called stomatal transpiration. The mesophyll cells of leaf provides large surface area for the evaporation of water. Water is drawn from xylem into mesophyll cells, from where it comes out and makes a water film on the cell walls of mesophyll. From here the water evaporates into the air spaces of the leaf. Water vapours then diffuse from air spaces towards stomata and then pass to outside air.

8.                 What is difference between lenticels and stomata?

Ans:    Stomata is the small pores which are present the inner surface of leaves.

            Lenticels are the small pores which are present in stem and branches of leaves.

9.                 What is meant by lenticels? Give its importance./ What are lenticels and where are they found in plant body?                            

Ans:    Lenticels are the small pores which are present in stem and branches of leaves.

            Importance of lenticels: Lenticels help in transpiration.

10.             State the process of opening and closing phenomenon of stomata in the leaf of plants.

Ans:    When a leaf transpires, the water concentration of its mesophyll cells drops. This drop causes water move by osmosis from the xylem of leaf into mesophyll cells. When one water molecule moves up in the xylem of the leaf, it creates a pulling force that continues all the way to root.

11.             How transpiration is controlled by opening and closing of stomata? Explain it.

Ans:    The responsibility of the stomata to regulate transpiration by the action of   guard cells. When guard cell gets water and become turgid, their turgidity increases and stomata opens. Hence the relation of stomata with turgidity is that when turgidity increases stomata opens and vice versa.

12.             How stomata open and close?

Ans:    Most plants keep their stomata open during the day and close them at night. When guard cells get water and become turgid, their shapes are like two beans and the stoma between them opens. When guard cells loose water and become flaccid, their inner sides touch each other and stoma closes.

13.             Describe the function of Stomata in Plants.

Ans:    It is the responsibility of stomata to regulate transpiration via the actions of guard cells.

14.             What is role of potassium ions in the opening of stomata?

Ans:    Potassium ions have played an important role in opening of stomata. Light cause the movement of potassium ion from epidermal cell into guard cell. Water follows these ions and enters guard cell. Thus their turgidity increases and stomata open.

15.             What is transpirational Pull?                                                

Ans:    The force that takes water from roots to upper parts of plants.

16.             Why transpiration is important for plants?

Ans:    When water transpire from the surface of plant, it leaves a cooling effect on plant. This is especially important in warmer environment. Moreover, the wet surfaces of leaf cells allow gaseous exchange.

17.             Why transpiration is known as necessary evil?  

Ans:    Transpiration as evil: During the condition of drought loss of water from plant result wilting and death.

            Transpiration as necessary: It creates transpiration pull responsible for conduction of water. It leaves a cooling effect to plant.

18.             What are the harmful effects of transpiration?

Ans:    Transpiration may be a harmful process in the sense that during the conditions of drought, loss of water from plant results in serious desiccation, wilting and often death.

19.                            Which factors affect the rate of transpiration?                                   

Ans:      i) Humidity          ii) temperature                  iii) pH

20.             What is the effect of temperature on the rate of transpiration?

 

Ans:    Higher temperature reduces the humidity of surrounding air and also increases the kinetic energy of water molecules. In this way it increases the rate of transpiration. The rate of transpiration doubles with every rise of 10^oC in temperature. But very high temperature i.e. 40-45^oC causes closure of stomata. So transpiration stops and plant does not loose the much needed water.

21.             How air humidity affects the transpiration?       

Ans:    In humid air, the rate of diffusion of water vapours is reduced and the rate of transpiration is low.

22.             What is Cohesion Tension Theory?                                                 

Ans:    Cohesion-Tension Theory:  According to this theory, the force which carries water (dissolved materials) upward through the xylem is transpiration pull. Transpiration creates a pressure difference that pulls water and salts up from roots.

23.             What is the difference between cohesion and adhesion?

Ans:    Adhesion: The attachment of water molecules to the inner surface of xylem vessel is called adhesion.

Cohesion: The mutual attachment of water molecules called cohesion.

24.             How transport of food occurs in plants?              

Ans:    Phloem transports synthesized food from the leaves to the rest of the plant body.

25.             What is meant by "source" in plants? Explain with an example.

Ans:    Source includes the exporting organs, typically a mature leaf or storage organ.

Example:  A storage organ is capable of storing food and exporting the stored materials. e,g root of beet is a sink in first growing season but becomes source in next growing season when sugars are utilized in the growth of new shoots.

26.             Define pressure-flow mechanism.  

Ans:       In pressure flow mechanism the food is moved from sources to sinks.  

27.             What is the difference between source and sink?                       

Ans:    Source:  Source include the exporting organs, typically a mature leaf or storage organ.

            Sinks:  Sinks are the areas of active metabolism or storage.

28.             Name two systems of transport in human.        

Ans:    (i) Blood Circulatory System.    (ii)  Lymphatic system.

29.             Explain transport of food in Human beings.

Ans:    The task of the transport of materials, food in human body is performed by two complex system i.e.

(a)               The blood circulatory system.        

(b)               The lymphatic system.

30.             Define blood circulatory system and also write two main components of the human blood circulatory system.                          

Ans:    The system in which blood circulate in network of arteries, veins and capillaries.

The main component of the human blood circulatory system are blood, heart and blood vessels.

31.             What do you meant by closed circulatory system? In which animal is it present?

Ans:    A system in which the blood never leaves the network of arteries, veins and capillaries.

Example: Higher animals like birds reptiles.

32.             What do you meant by blood? Write composition of a healthy man.

Ans:    The blood is a specialized body fluid (a connective tissue) that is composed of the liquid called blood plasma and blood cells.

            In a healthy person, plasma constitutes about 55% by volume of blood and cells or cell like bodies are about 45% by volume of the blood.

33.             What is meant by human blood plasma?                        

Ans:    Blood plasma is pale yellow liquid, component of blood that normally holds the blood cells in whole body contain water, salts; protein make up 55% of body is called plasma of blood.

34.             What is fibrinogen? Write down its function.

Ans:    Fibrinogen: It is a blood clotting protein in the blood.

            Function: It helps in clotting blood.

35.             Write the names of two proteins present in blood plasma.

Ans.     Albumin is most abundant protein of plasma and globulins make up 38% of blood proteins. It contains 90-92% water, 8-10% dissolved substances, 0.9% salts and 7-9% proteins. 

36.                            What is composition of Blood Plasma?

Ans:       Composition of blood plasma is consisting of protein, salts, water in vacuoles of body.

37.             How blood is taken from artery? How is plasma separated from blood?

Ans:    Blood is taken from an artery and an anticoagulant (chemical that inhibits blood clothing) is mixed in it. After five minutes plasma separates from blood cells, which settle down.

38.             Name different types of blood cells.

Ans:    1- Red Blood Cells (Erythrocytes)    2- White Blood Cells (Leukocytes)

            3- Platelets (Thrombocytes)

39.                            What are Red Blood Cells?  Write down their number in human beings.

Ans:      Red blood cells are called erythrocytes and they have oxygen and also part of hemoglobin. Human body contains 5 million cells per cubic.

40.             What is the average life of R.B.C?

Ans:    The average life of R.B.C. is that 2-10 million red blood cells are formed and destroyed every second.

41.             What is the function of red blood cells?

Ans:    About 95% of the cytoplasm of red blood cells is filled with hemoglobin, which transports oxygen and small amount of carbon dioxide. The remaining 5% consists of enzymes, salts and other proteins.

42.             How white and Red Blood Cells Differs?

Ans:    Red blood cells are like biconcave disc without nucleus, contain hemoglobin. While blood cells are Granular and agranular, contain nucleus, larger in size than RBCs.

43.                            What is the number of White Blood Cells in human beings and what is their function?                                                                                                  

Ans:       White blood cells are called army of body. It defends the body against germs. Normal numbers of WBC_S in 1 cubic millimeter of blood contains 7000-8000 WBCs.

44.             Write the names of two main types of white blood cells.

Ans:    1- Granulocytes                     2- Agranulocytes

45.             Write the functions of white blood cells.          Or        ‘What is the function of leukocytes?                                                                                

Ans:    Functions of WBCs:

(i)                 Their function as main agents in body’s defense system.

(ii)               Destroy small particles by phagocytosis. (Neutrophils).

(iii)             Break inflammatory substances and kill parasites (Eosinophils)

(iv)             Prevent blood clotting (Basophils)

46.             Write the function of T and B lymphocytes.

Ans:    B and T lymphocytes produce antibodies and kill germs.

47.             Differentiate between Eosinophils and Basophils.

Ans:   

Eosinophils	Basophils
These can break inflammatory substances and kill parasites.	These can prevent blood clotting.

48.             What are Thrombocytes? Describe their functions.

Ans:    Thrombocytes:  They are not cells, but are fragments of large cells of bone marrow, called megakaryocytes. They do not have any nucleus and any pigment. They contain average life span of platelets is about 7 to 8 days.

Function: Platelets help in blood clotting.

The clot serves as a temporary seal at the damaged area.

49.             What is the number of platelets in blood and what is their function?

Ans:    One cubic millimeters of blood contains 250,000 platelets.

            Function: Platelets helps in blood clotting.  The clot serves as a temporary seal at the damaged area.

50.             What do you meant by pus?/ How Pus is formed?                    

Ans:    Pus:  Pus is whitish watery fluid which is produced at a site of infection due to the death of antigen and antibodies.

51.             You see “Pus” at the site of infection on your skin. How is it formed?

 

Ans:    When wound is formed on body part then white blood cell is break the germs and make a white substance on wound is called pus.

52.             Write the effect of Dengue Fever on platelets.             

Ans:    Platelets are destroyed. Their number reduces. Patient bleeds from the nose, gums and under the skin.

53.             Patients bleed from the nose, gums and under the skin in dengue fever. Why?

Ans:    In dengue fever, there is sharp decrease in the number of platelets in blood. Because of this, patients bleed from the nose, gums and under the skin.

54.             Describe the function of Platelets in blood.

Ans:    They serve as a temporary seal at the damaged area. They help in blood clotting.

55.             Write the names of two diseases of blood.

Ans:    1- Leukaemia (Blood cancer)                       2- Thalassaemia

56.             What is leukaemia?

Ans:    Leukaemia is a disease of blood in which lack of blood in body. It also increases development of cancer in body.

57.             What is Thalassaemia? How can it be cured? / What is the cause of Thalassaemia and what is its treatment.

Ans:    It is a genetic problem due to mutation in the gene of hemoglobin the mutation results in the production of defective hemoglobin and the patient cannot transport oxygen properly.

            Treatment:  Blood replacement regularly. Bone marrow transplant.

58.             Define antigen. 

Ans:    Antigen is a molecule that can stimulate an immune response (antibodyproduction).

59.             Write blood groups of human blood.

Ans:    There are four different blood groups.

1.         A person antigen A on RBCs has blood group A.

2.         A person antigen B on RBCs has blood group B.

3.         A person antigen A,B on RBCs has blood group AB.

4.         A person none of A,B antigen has blood group O.

60.                            How do we classify blood groups in terms of the ABO blood group system?

Ans:       If  antigen A is present it is called A group and antigen B is refer to B group. Antigen A and B is not present then blood group is O and if antigen A,B  is present it is called AB group.

61.             Which persons are universal donors and universal recipients?

Ans:    Universal donor: Blood group O individuals are called universal donor. Universal recipients: Blood groups AB individuals are universal acceptor.

62.                            Why O blood group individuals are called universal donors?       

Ans:      O blood group is called universal donor because they can donate blood to the recipients of every other blood group.

63.             What is Rh blood group system and who discovered it.

Ans:    In this system, there are two blood group i.e. Rh- positive and Rh-negative. These blood groups are distinct from each other on the basis of antigens called Rh factors present on the surface of the RBCs. Karl Landsteiner discovered the Rh-blood group system

64.             What is blood cross match?

Ans:    It is used for the confirmation of no agglutination; blood samples of donor and the recipient are cross-matched.

65.             What is meant by transfusion?

Ans:    It is the process of transferring blood or blood based products from one person into the circulatory system of another.

66.             Differentiate between pericardium and pericardial fluid.

Ans:   

Pericardium	Pericardial fluid
Heart is closed in a sac known as pericardium.	A fluid between the pericardium and heart walls is called pericardial fluid.

67.             What is the function of Pericardium?       

Ans:    It is sac-like structure that encloses the heart which protects the heart from external danger. It is found between pericardium and heart walls.

68.                            What is pericardial fluid?

Ans:    It is abnormal amount of fluid between heart and pericardium. It is serious fluid that is found in brain.

69.                            What is meant by cardiac cycle?                                                               

Ans:      The contraction and relaxation of chamber of heart that form one heart beat is called cardiac cycle.

70.             Write down two names of main steps of  cardiac cycle.

Ans:    1- Systole                   2- Diastole

71.             Write the definition of systole and diastole.      

Ans:    Diastole:   The relax period of heart chamber is called Diastole.

            Systole:  The contraction period of heart chamber is called systole.

72.             Define cardiac diastole.

Ans:    Atria and ventricles relax and blood is filled in atria. This period is called cardiac diastole.

73.             What is heartbeat?                                                             

Ans:    The relaxation of heart chambers fills them with blood and contraction of chambers propels blood out of them. The alternating relaxations and contractions make up the cardiac cycle and one complete cardiac cycle makes one heartbeat.

74.             How tricuspid value do its work in human heart.

Ans:    The opening b/w right atrium and right ventricle is guarded by a valve known as tricuspid.

75.             Differentiate between bicuspid valve and tricuspid valve./ what is bicuspid valve.

Ans:    Difference between bicuspid and tricuspid.

Bicuspid	Tricuspid
The opening between left atrium and left ventricle is guarded by a value known as bicuspid.	The opening between right atrium and right ventricle is guarded by a value known as tricuspid.
It has two flaps.	It has three flaps.
It carries blood to all parts of body.	It carries blood to lungs.

76.                            Why the human heart is called double pump?/ How does human heart work as double pump.                                                                                                               

Ans:      Human heart works as a double pump. It receives deoxygenated bloods and then also receives at same time oxygenated blood so, called as double pump.

77.             Why blood in pulmonary circulation is low pressure than that of in systematic circulation?          

Ans:    Because it gives sufficient time to blood for gaseous exchange in lungs.

78.                            What is meant by Pulmonary Veins? Write its function.

Ans:       Pulmonary veins take oxygenated blood from lungs to heart.

79.             Define pulmonary circulation and systematic circulation.          

Ans:    Pulmonary circulation: The pathway on which deoxygenated blood is carried from heart to lungs and in return oxygenated blood is carried from lungs to heart is called pulmonary circulation or circuit.

Systemic circulation: The pathway on which oxygenated blood is carried from heart to body tissues and in return deoxygenated blood is carried from body tissues to heart is called systematic circulation.

80.             How is lubb-dubb?  

Ans:    When ventricles contract, bicuspid and tricuspid values close and lubb sound is produced. Similarly when ventricles relax, the semilunar values close and “dubb” sound is produced. Lubb dubb can be heard with the help of a stethoscope. 

81.             What is meant by pulse?                                                    

Ans:    Pulse is the rhythmic expansion and contraction of an artery as blood is forced through it by the regular contractions of heart. Pulse can be felt at areas where artery is close to skin for example at wrist, neck, groin or top of foot. Most commonly, people measure their pulse in their wrist.

82.            Define capillaries                                                               

Ans:    Capillaries are the smallest blood vessels present in tissues. These are the vessels through which exchange of materials between blood and tissue fluid is carried out through capillaries.

83.             Write the role of capillaries in human blood Circulatory System.-

Ans:    These carry deoxygenated blood from all body parts to the heart.

84.             What is the function of Arteries in human body?

Ans:    These are the blood vessels which carry blood away from the heart.

85.             Differentiate between Arteries and Veins./ What are arteries.

 

Ans:   

Arteries	Veins
These are the blood vessels that carry blood away from the heart.	These are the blood vessels that carry blood towards heart.
The lumen of arteries is narrower than veins.	The lumen of veins is broader than arteries.
The middle layer is comparatively thick.	The middle layer is comparatively thin.

86.          What do you meant by vascular surgery?                         

Ans:    Vascular surgery is the field in surgery in which disease of arteries and veins (like thrombosis etc.) are managed by surgical methods. A vascular surgeon treats the diseases of all parts of blood circulatory system except of heart and brain.

87.          What is the function of veins?

Ans:    In adults, all veins with the exception of pulmonary veins, carry deoxygenated blood.

88.             Write role and names of two scientists who work on Blood Circulatorysystem./ Write the names of two famous, scientists who revealed much knowledge of blood circulatory system.

Ans:    Too important scientists Ibn-e-Nafees and William Harway. They were honoured by the first scientist who described the pathway of blood.

89.          Write down two main reasons of cardio vascular diseases.       Or

Write causes of cardio vascular disorders.

Ans:    Main reasons of cardio vascular diseases:

1-                 Advanced age                        2- Diabetes                 3- Tobacco Smoking

3- High blood concentration of low density lipids (e.g. cholesterol) and triglycerides.

4- High blood pressure (hypertension)     

90.             Write names of two diseases of arteries.

Ans:    Atherosclerosis, arteriosclerosis

91.             Explain two factors which can cause transpirational pull.

Ans:    (i)         Water molecules cohere to each other.

            (ii)        Water molecules adhere to the walls of xylem tube.

(iii)       Water is held in a xylem that has small diameter.

92.             What is Arteriosclerosis?                                             

Ans:    Arteriosclerosis: Hardening of arteries occurs when calcium (ca) isdeposited inside the arteries.

93.             What is the cause of atherosclerosis?

Ans:    Arthrosclerosis is commonly referred to as a narrowing of arteries. It is a chronic disease in which there is accumulation of fatty materials, cholesterol or fibrin in arteries.

94.             What is meant by embolus?

Ans:    If a thrombus dislodges and becomes free-floating is called embolus.

95.             What is plaques?                             

Ans:    Accumulation of cholesterol is the prime contributor to atherosclerosis. It results in the formation of multiple deposits called plaques.

96.             What do you know about myocardial infarction?                       

Ans:    It is more commonly known as a heart attack it occurs when blood supply to part of a heart is interrupted and leads the death of heart muscles. Heart attack may be caused by the blood clot in coronary artery. Severe chest pain is most common symptom and may be in the form of sensation of tightness, pressure or squeezing.

97.             What is angina pectoris? / Write its symptoms.            

Ans:    It means a chest pain. It is not severe as heart attack. The pain may occur in heart and often in left arm and shoulder. It is a warning sign that blood supply to heart muscles is not sufficient but shortage is not enough to cause tissue death.

98.             What is Angioplasty and bypass surgery?

Ans:    Angioplasty: It is a mechanical widening of a narrowed or totally obstructed blood vessels.

            Bypass surgery:  It is a surgery in which arteries and veins from elsewhere in the patient’s body are grafted to the coronary arteries to improve blood supply to heart muscles.