Biology For Class IX - Chapter No.9 - Transport - Review Text Book Exercise

GO TO INDEX
CHAPTER 9
TRANSPORT
Review Text Book Exercise

1. Encircle the correct answer:
(i) The movement of organic materials (food) take place through:
(a) Xylem
(b) Vessels
(c) Tracheid
(d) Phloem ✔

(ii) What regulates the flow of water through the xylem?
(a) Passive transport by the endodermis
(b) The number of companion cells in the phloem
(c) The evaporation of water from the leaves ✔
(d) Active transport by sieve-tube membrane

(iii) Phloem transport of sucrose can be described as going from “source to sink” which of the following would not normally function as a sink?
(a) Mature leaf ✔
(b) Storage organ
(c) Growing root
(d) Both 'b' and 'c'

(iv) Human plasma proteins include which of the following?
(I) Fibrinogen  (II) Haemoglobin   (III) Albumin
(a) I only
(b) II only
(c) I and II
(d) I and III ✔

(v) Which of these are involved in the clotting of blood?
(a) Platelets ✔
(b) Haemoglobin
(c) Albumin
(d) Globulin

(vi) In human heart blood returning from lungs first drains into the:
(a) Left atrium ✔
(b) Left ventricle
(c) Right atrium
(d) Right ventricle

(vii) Root hairs are most important to a plant because they:
(a) Store starch
(b) Contain xylem tissues
(c) Provide a habitat for nitrogen fixing bacteria
(d) Increase the surface area for absorption ✔

(viii) A type of circulatory system blood flow through the spaces among tissues called.\:
(I) Open type circulatory system   (II) Close type circulatory system   (III) Pulmonary circulatory system
(a) I only ✔
(b) II only
(c) I and II
(d) II and III

(ix) Part of root between epidermis and endodermis called:
(a) Xylem
(b) Root hair
(c) Phloem
(d) Cortex ✔

(x) Movement of water molecules from the area of higher water potential to the area of lower water potential called:
(a) Diffusion
(b) Osmosis ✔
(c) Active transport
(d) Water potential

2. Fill in the blanks:
(i) Loss of internal water of plant in the form of vapours from aerial parts of plants is called transpiration.
(ii) In flowering plants xylem is made up of four types of tissues.
(iii) Root hair is long, thin and tubular structure, it increases surface area which increases the rate of absorption of water.
(iv) Opening and closing of stomata is also regulated by guard cells.
(v) A type of cancer that affects the blood, bone marrow and lymphatic system called leukemia.
(vi) Pumping of blood by the rhythmic pulsation of heart throughout the body is called heart beat.
(vii) Relaxation of heart muscles and allowing the chambers to fill with blood called diastole.
(viii) Dead cells of xylem vessels arranged vertically have empty space inside called lumen.
(ix) Colourless, irregular in shape, nucleated and larger sized cell than R.B.Cs called leucocytes or WBC.
(x) Inherited condition that affects the blood hemoglobin called Thalassemia.

3. Define the following terms: (i) Blood (ii) Water potential (iii) Diffusion (iv) Stomata (v) Bifacial leaves (vi) Humidity (vii) Sieve plates (viii) Sink (ix) Granulocytes (x) Heart beat
Ans: 1. Blood:
Blood is a special type of connective tissues, found in the form of fluid which circulates in the body. It transports substances in the body of an organism. It has two main parts:
(i) Plasma
(ii) Corpuscles

2. Water Potential:
Water potential is a measure of the potential energy in water, or the difference in potential energy between a given water sample and pure water (at atmospheric pressure and ambient temperature).

OR

Water potential is the potential energy of water per unit volume relative to pure water in reference conditions. It is the tendency of water to move from one area to another due to osmosis, gravity, mechanical pressure and matrix effects such as capillary action (which is caused by surface tension). The concept of water potential has proved useful in understanding and computing water movement within plants, animals, and soil. Water potential is typically expressed in potential energy per unit volume.

3. Diffusion:
"It is the movement of molecules from an area of high concentration of the molecules to an area with a lower concentration. The difference in the concentrations of the molecules in the two areas is called the concentration gradient."

OR

“It is a process in which the random movement of the molecules or ions takes place from a region of higher concentration to a region of lower concentration."
Few substances freely diffuse across the cell membrane.

4. Stomata:
Stomata, also called stoma (plural stomata or stomas) are the microscopic openings or pores in the epidermis of leaves and young stems. Stomata are generally more numerous on the underside of leaves. A stomata is surrounded by two kidney shaped, guard cells, these cells contain chloroplast while other epidermal cells do not. The guard cell control the opening and closing of stomata.

5. Bifacial leaves:
A leaf having upper and lower surfaces that are structurally different. Leaves that have stomata at lower epidermis called bifacial leaves e.g. leaves of mango plant.

6. Humidity:
Humidity is the concentration of water vapor present in the air. Water vapor which is the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present.

7. Sieve plates:
Sieve tubes are the perforated transverse wall between two sieve elements of phloem in vascular plants (Angiosperms). The perforations in sieve plates allow water and dissolved organic solutes to flow along the sieve tube. The sieve plates are lined with cellulose.

OR

Sieve plates are the connection sites between sieve elements. The sieve tubes or sieve tube elements of phloem is made up of columns of elongated and thin walled living cells. The transverse walls separating the cells have lots of minute pores. The cross walls look like a sieve and therefore called sieve plates.

8. Sink:
Sink is defined as going down slowly, or to drop beneath the surface or normal level. In plants, the points of sugar delivery, such as roots, young shoots, and developing seeds, are called sinks. In other words sink refers to the part of the plant where the Substrate can be stored (e.g. roots or stem for starch)

9. Granulocytes:
Granulocytes are a type of white blood cell, also called granular leukocyte. These granules are type of immune cell that contain small granules with enzymes (protein), which are released during infections, allergic reactions, and asthma. Neutrophils, eosinophils, and basophils are specific type of granulocytes.

10. Heart beat:
The pumping of blood by the rhythmic pulsation of heart throughout the body is called heart beat. It is a two phase pumping action of blood that takes less than a second. The relaxation of heart muscle and allowing the chambers to fill with blood is called diastole. The contraction of heart muscle and pumping the blood from the chambers into the arteries named as systole.

4. Distinguish between the following in tabulated form:
(i) Pulmonary circuit and systematic circuit
(ii) Open type circulatory system and close type circulatory system
(iii) Xylem and Phloem
(iv) Arteries and Veins
(v) W.B.Cs and R.B.Cs
Ans: Difference Between Pulmonary circuit and systematic circuit

S.No.	Pulmonary circulation	Systemic circulation
1.	This involves circulation of blood between the heart and the lungs.	This involves circulation of blood between the heart and body organs (except lungs).
2.	It is the function of the right side of the heart.	It is the function of the left side of the heart.
3.	It carries deoxygenated blood from the right ventricle to the lungs through pulmonary artery.	It carries oxygenated blood from the left ventricle to rest of the body by aorta.
4.	It returns oxygenated blood from the lungs back to the left atrium of heart by pulmonary vein.	It returns deoxygenated blood from the body back to theright atrium of heart by superior and inferior vena-cava.
5.	It is composed of pulmonary artery and pulmonary vein.	It is composed of superior and inferior vena-cava, aorta.
6.	It helps to release carbon dioxide from blood while dissolving oxygen in the blood.	It helps to provide nutrients and oxygen to the metabolizing cells in the body.

(ii) Difference Between Open type circulatory system and close type circulatory system

S.No.	Open Circulatory System (OCS)	Closed Circulatory System (CCS)
1.	The hemolymph directly bathes the organs and tissues.	The blood circulates within closed vessels.
2.	The blood and interstitial fluid cannot be distinguished.	Blood and interstitial fluid are distinct.
3.	Blood is pumped into the body cavity.	Blood is pumped through the vessels by the heart.
4.	Capillary system is absent.	Capillary system is present.
5.	Blood is in direct contact with the surrounding tissues.	Blood is not in direct contact with the tissues.
6.	Nutrients are exchanged directly between blood and tissues.	The nutrients are exchanged via tissue fluid.
7.	No transport of gases.	Gases are transported.
8.	The fluid flowing in this system is called hemolymph.	Fluid flowing in this system is called blood.
9.	No respiratory pigments are present.	Respiratory pigments are present.
10.	The volume of blood cannot be controlled.	The volume of blood can be controlled by the contraction and relaxation of blood vessels.
11.	Hemolymph flow is slow.	Blood flow is rapid.
12.	The open spaces are called sinuses and lacunae.	Closed spaces involve arteries and veins.
13.	Dorsal blood vessel present.	Dorsal and ventral blood vessels present.
14.	Example: Present in molluscs and arthropods i.e. Snails, clams, cockroaches and spiders etc.	example: Present in annelids and vertebrates i.e. Humans, squids, cats, earthworms etc.

(iii) Difference Between Xylem and Phloem

S.No.	Xylem	Phloem
1.	Xylem is a vascular tissue that transports water and dissolved minerals absorbed from the roots to the aerial parts of the plant.	Phloem is a vascular tissue that transports food prepared during photosynthesis from leaves to storage organs and growing parts of the plant.
2.	It is located in the centre of the vascular bundle.	It is located on the outer side of the vascular bundle.
3.	They are present in roots, stems and leaves.	They are present in stems and leaves, which later grow in roots, fruits and seeds.
4.	It consists of tracheids, vessel, xylem parenchyma, xylem sclerenchyma and xylem fibres.	It consists of companion cells, sieve tubes, phloem fibres, and the phloem parenchyma.
5.	Xylem tissues are the tubular-shaped structure, with the absence of cross walls. This tissue resembles the shape of a star.	Phloem tissues are tubular-shaped, elongated, structures with the presence of walls with thin sieve tubes.
6.	The total amount of xylem tissue is more.	The total amount of phloem tissue is less.
7.	Xylem fibres are smaller.	Phloem fibres are larger.
8.	These tissues move in a Unidirectional. (only in one direction – upward direction)	These tissues move in a Bidirectional. (both ways – up and down)
9.	The cells of the xylem tissues are dead cells except for the parenchyma cells.	The cells of the phloem tissues are living cells except for the blast fibre.
10.	The cell wall of the cells in xylem is thick-walled.	The cell wall of the cells in phloem is thin walled.
11.	Provides mechanical strength to the plant and helps in strengthening the stem.	Do not involve in mechanical support.
12.	Two type of conductive cells are present in xylem; tracheid and vessels.	Only one type of conductive cell is present in phloem; sieve tubes.
13.	Xylem forms most of the bulk of the wood.	Phloem forms most of the bulk of the bark.

(iv) Difference Between Arteries and Veins

S.No.	ARTERIES	VEINS
1.	Carry blood away from the heart to various parts of the body.	Carry blood towards the heart from the various parts of the body.
2.	Valves are absent	Valves are present.
3.	Carry pure, oxygenated blood and nutrient-rich blood except pulmonary artery.	Carrying impure, deoxygenated blood except pulmonary vein.
4.	Arteries end in capillaries.	Veins start from capillaries.
5.	Located deep within the body.	Peripherally located closer to the skin.
6.	They do not collapse when there is no blood in it.	They collapse when there is no blood in it or cut across.
7.	Arteries are further divide into arterioles.	Veins are further divide into venules.
8.	Consists of three distinct layers, which are rounded, rigid, thicker and highly muscular.	Consists of three distinct layers, which are thin and collapsible.
9.	Lumina is narrow.	Lumina is wide.
10.	Reddish in colour.	Bluish in colour.
11.	High pressure, as the blood flows by the pumping pressure of the heart.	Low pressure, as the blood flows by the capillary action of the veins.
12.	Arteries show spurty movement of blood giving pulse.	Veins show sluggish movement of blood.

(iv) Difference Between W.B.Cs and R.B.Cs

S.No.	Red Blood Cells (RBCs)	White Blood Cells (WBCs)
1.	They are also called Erythrocytes.	They are also called Leucocytes.
2.	They are smaller in size and the most abundant cell in the blood.	They are larger in size and fewer in number than RBCs.
3.	Non nucleated and Biconcave disc-shaped	nucleated and Irregular or round in shape
4.	Contain a special type of complex protein called hemoglobin (respiratory pigment) due to which red in colour.	Hemoglobin is absent in WBCs due to which they are white or colourless.
5.	RBCs cannot diffuse out through capillary wall.	WBCs can diffuse out through capillary wall.
6.	RBCs help in gaseous transport.	WBCs help in killing bacteria and foreign particles.
7.	Belong to the cardiovascular system.	Belong to the lymphatic system.
8.	Single type.	In healthy people, there are at least five types of white cells including granulocytes, monocytes, and lymphocytes.
9.	The average life span of 120 days.	Life span ranges from 5-21 days.
10.	Disorders result in anemia, thalassemia, polycythemia vera, etc.	Lymphoma, Leukemia, Myelodysplastic syndrome (MDS)

5. Write short answers of following questions:
(i) Why capillaries are made up of single layer of endothelium?
Ans: Capillaries are made up of single layer of endothelium because it make them a bit “leakier” than other types of blood vessels, so substances such as glucose, oxygen and wastes can quickly pass through it on their way to or from the cells with greater ease.

(ii) Why transpiration is necessary for plants?
Ans: SIGNIFICANCE OR IMPORTANCE OF TRANSPIRATION:

1. Help In Ascent Of Sap: By active transpiration, a suction force or a transpiration pull is created which helps in the ascent of sap.
2. Help in Absorption: Transpiration also increases the rate of absorption because the loss at one end increases demand on other end.
3. Remove Excess Of Water: Transpiration gets rid of the excess amount of water from plant.
4. Prevent Overheating: Transpiration helps in maintaining the temperature of plant for its metabolism and survival because evaporation causes cooling.
5. Help In Stomatal Mechanism: Opening and closing of stomata is also regulated by transpiration, which indirectly influences upon the rate of photosynthesis and respiration.
6. Cause Wilting : Excessive loss of water from aerial parts which results in wilting and dehydration and ultimately may lead to death of plant in extreme conditions.

(iii) How water flow through xylem?
Ans: Co-hension theory explained the water flows through xylem. According to this theory, the force which carries water and dissolved materials) upward through the xylem is tanspirational pull. Transpiration creates a pressure difference that pulls water and salts up from roots. When a leaf transpires (loses water), the water concentration of its mesophyll cells drops. This drop causes water to move by osmosis from the xylem of leaf into mesophyll cells. When one water molecule moves up in the xylem tissue of leaf, it creates a pulling force that continues all the way to the root. This pulling force created by the transpiration of water is called transpirational pull. It also causes water to move transversely, from root epidermis to cortex and pericycle.

(iv) Why veins contain semilunar valves in it?
Ans: Veins contain semilunar valves because they prevent the backward flow of blood from the arteries into the ventricles and allow blood to be pumped forward into the major arteries.

(v) Why atherosclerosis cause myocardial infraction and stroke?
Ans: Atherosclerosis is a disorder in which bad fats (i.e. low density lipoprotein or LDL and cholesterol) get deposited in blood vessels internal layer. Accumulation of fats leads to gradual narrowing of lumen of blood vessel. Narrow lumen leads to gradual compromise of blood supply to target organs, and leads to myocardial infraction and stroke.

6. Write detailed answers of the following questions:
(i) Describe structure of human heart with suitable diagram.
Ans: External Structure Of Human Heart:

• Heart is the major organ of Circulatory system. It is a muscular pump which keeps the blood circulating throughout the body.
• Location: It is located in the thorax slightly at the left side.
• Pericardium: It is enclosed in a fibrous bag like protective cover called Pericardium. It is conical in shape externally.
• Pericardial fluid: The space between pericardium and heart is pericardial cavity which is filled with a fluid called pericardial fluid. This fluid reduces friction and Pericardium protects the heart, prevent it from over extension.

Internal Structure Of Human Heart:
Internally, it consists of four chambers:

1. The upper two are thin walled called atria (sing: artrium). They divide into:
   i. Right Auricle
   ii. Left Auricles
2. the lower two are thick walled called ventricles. They divide into:
   iii. Right Ventricles
   iv. Left Ventricles

Auricles OR Atria (sing: artrium):

• The upper two are thin walled chambers called auricles atria.
• Atria are completely separated from each other by a septum called inter-atrial septum.
• Each atrium is connected (opened) with its ventricle by an auriculo-ventricular aperture.
• The right atrium receives deoxygenated blood from all parts of the body through superior and inferior vena cava.
  * The right atrium and right ventricle are connected by Tricuspid Valve.
• Similarly, left atrium received oxygenated blood from lungs through pulmonary veins.
  * The left atrium and left ventricle are connected by bicuspid valve
•  These valves prevent the backward flow of blood from the ventricles to the atria.

Function Of Atria:
The function of atria is to stretch to receive blood as it returns to the heart and then contract with enough force to push the blood through the atrioventricular valves into the ventricles. This requires a lower pressure than that developed in the ventricles, so the walls of the atria are much thinner and more elastic than those of the ventricles.

Ventricles:

• The lower two are thick walled chambers called ventricles.
•  The two ventricles are separated from each other by a muscular partition called inter-ventricle septum.
• Two main blood vessels (Aorta & Pulmonary arch) are arising from ventricles to carry blood from heart to all parts of the body.
• The blood from the right ventricle is pumped through pulmonary arch to the lungs for oxygenation
• While the blood from the left ventricle is pumped through a systemic aorta to all the parts of the body.
• The pulmonary arch and systemic aorta, both are guarded by semi-lunar valves to prevent backward flow of blood.
• There is a difference in thickness of muscle wall of the left ventricle as compared to right ventricle.

Function Of Ventricle:
The left ventricle is much thicker and narrow in space. This is related to their functions. The right ventricle only pumps blood to the lungs while the left ventricle pumps blood to all other parts of the body. The resistance to blood flow through the body capillary networks is for higher than that through the lung capillaries so, a high pressure is developed in the systemic circulation, it requires a thicker muscle wall and narrow space.

(ii) What is blood? Explain composition of blood and function of corpuscles.
Ans: BLOOD:
Blood is a special type of tissue, found in the form of fluid which circulates in the body. It transports substances in the body of an organism.

COMPONENTS OF BLOOD:
It consists of two parts:

1. Plasma
2. Corpuscles

i) Plasma:

• Plasma is the fluid part of blood and constitutes about 55% by volume of whole blood. It is pale yellowish liquid.
• About 90% of plasma is water in which complex mixture of various substances are dissolved.
• There are dissolved mineral salts like bicarbonates, sulphates, chlorides and phosphates of sodium (Na) and potassium (K). All these are found in the form of ions.
• Salts of calcium are also present in blood for clotting of blood.
• Soluble proteins are also present in plasma i.e. Serum albumin, Serum globulin, fibrinogen and prothrombin. The last two play important part in clotting of blood.
• Antibodies are also present in plasma, which are involved in fighting diseases.
• Plasma contains digested food substances such as glucose, amino acids, fatty acids and vitamins.
• It also contains excretory products such as Urea, Uric acid and creatinine. Carbondioxide (CO₂) is also present as bicarbonate ions.
• It also contains hormones.

Function:

• It provides medium for exchange of materials between the body cells and the blood.

ii) Corpuscles:
In man, 45%of the blood consists of blood cells. The blood cells are of the following types:

1. Erythrocytes OR Red Blood Cells (RBCs)
2. Leucocytes OR White Blood Cells (WBCs)
3. Platelets

a) Erythrocytes OR Red Blood Cells (RBCs):

• In mammals, RBCs are disc like circular, bi-concave cells in shape.
• They are 0.007-0.008 mm in diameter in size. RBCs are non-nucleated, and do not have mitochondria, endoplasmic reticulum and Golgi bodies.
• 1mm³(1 drop) of blood contains approximately 5 million RBCs.
• They also contain respiratory pigments i.e. haemoglobin. Haemoglobins are red pigment protein containing iron. The red color of the blood is due to the haemoglobin of RBcs.
• RBCs are produced in bone marrow and destructed in spleen and liver. There life is 120 days on average.

Function:

• Haemoglobin of RBCs:
  * Transports O₂ from lungs to body cell.
  * Transports CO₂ from body cell to lungs.
• When haemoglobin are bronken down:
  * Iron released (stored in liver)
  * Bile pigments (excreted in GUT)

b) Leucocytes OR White Blood Cells (WBCs):

• Leucocytes or WBCs are colourless, irregular in shape, nucleated and lager sized cell than R.B.Cs.
• 1 mm³ contains approximately 7000 WBCs.
• They are of several types basis on the shape of the nucleus.

Function:

• Leucocytes or WBCs are commonly known as the "Police of the Body". They protect the body by killing germs that enter the body.
• There are several types of White blood cells which perform different functions.

Types Of Leucocytes OR White Blood Cells (WBCs):

c) Platelets:

• Platelets are the fragments of cells which are formed from large precursor cells in the bone marrow.
• On injury, exposure to the air stimulate the platelets at cut end to produce an enzyme in blood. This enzyme causes the soluble plasma protein fibrinogen to form insoluble fiber of another protein fibrin which forms a network of fibers around wound.

Function:

• It protects blood to flow that is called clot, which prevents bleeding and stops the entry of pathogen.

Blood Components In Tabular Form

(iii) What is transpiration? Explain mechanism of transpiration and factors affecting transpiration.
Ans: TRANSPIRATION:
Plants absorb water continuously from soil. Some of its quantity utilized in photosynthesis and other metabolic functions while the rest is retained in cell to maintain turgidity of cell. Some water is removed in the form of vapours.
"The loss of internal water of plant in the form of vapours from aerial part of plant is called transpiration. It mainly takes place through special pores guarded by specialized guard cells called stomata (sing: stoma)."

MECHANISM OF TRANSPIRATION:
Transpiration process may occur through stomata in leaves, through the cuticle present on leaf epidermis, and through special openings called lenticels present in stems of some plants.
The mesophyll cells of leaf provide large surface area for the evaporation of water. The mesophyll cells of the leaf withdraw water from the xylem tissue by osmotic diffusion and become turgid. From the surface of the turgid cells, water gets evaporated and collects in the intercellular spaces. Thus, the air present in the intercellular spaces becomes saturated while the atmospheric air is usually unsaturated (except just after the heavy rain) due to which the water vapour diffuses outwardly from intercellular spaces of leaf to the environment through stomata, cuticle and lenticle.

Factors affecting the rate of transpiration:
The rate of transpiration is also affected by some of the following environmental factors.

1. Temperature:
   Rate of evaporation of water from cell surface increases with increase in temperature.
   
   
2. Humidity:
   Transpiration takes place only when concentration of the vapours must be low outside than inside, so dry atmosphere is also the condition for transpiration. The rate of transpiration decrease with the increase in water vapours in atmosphere i.e. humidity.
   
   
3. Wind:
   The increase in wind velocity increases the rate of transpiration. The wind decreases the water vapours around plant and makes the atmosphere dry.
   
   
4. Atmospheric Pressure:
   Low atmospheric pressure increases the rate of transpiration through reduction in the density of air.