TRANSPORT OF MATERIAL IN ANIMAL BIOLOGY QUESTIONS AND ANSWERS

TRANSPORT OF MATERIAL IN ANIMAL QUESTIONS AND ANSWERS

A list of questions from www.elimutz.com with answers are hereby to help you make revision from the ingested concepts during  class session or from individual studies, questions covers the current syllabus and are useful to students who are prepared for different examinations also to teachers who compose examinations, are also useful to all learners since the concepts are applied in daily life situations, welcome let make future bright

1. i)List the components of animal transport systems

• system of blood vessels in which materials are circulated round the body
• blood, a fluid medium which contains dissolved substances and cells
• the heart, a pumping mechanism which keeps blood in circulation

ii) Distinguish between closed and open circulatory systems

• closed system has blood vessels through which blood moves eg vertebrates
• open system has no blood vessels hence blood is in direct contact with tissues e. g arthropoda

iii) What are the advantages of the closed circulatory system over open circulatory system?

• Closed system has continuous vessels hence able to generate high pressure
• Circulates blood over longer distance
• Circulates blood at a faster rate
• Efficient transport of nutrients and waste products
• Animals are more active

iv) Distinguish between single circulatory system and double circulatory system Single circulatory

• blood passes through the heart once in a complete circuit of the body
• Double circulation
• blood enters the heart twice in a complete circulation
• Pulmonary circulation from the heart to lungs and back
• Systemic circulation from the heart to body systems and back

2.  i) Describe the general layout of the transport system in mammals

• blood which is a fluid tissue of the body carrying food substances, oxygen, carbon IV oxide and metabolic water.
• arteries which are elastic tubes carrying blood from the heart to cells
• veins which are blood vessels carrying blood away from the cells to the heart
•  capillaries which are extremely numerous and are microscopic channels connecting arteries to veins

ii) Describe the structure and function of the mammalian heart

• the heart is a four-chambered hollow muscle located in the thoracic cavity
• it consists of two small receiving chambers, the atria(auricles) and two larger pumping chambers, the auricles
• the left ventricles is the most powerful and has the thickest walls
• this is because it is the chamber which pumps blood throughout the body
• each time it contracts, blood is forced out into the elastic arteries(aorta)
• blood moves on to the capillaries
• from capillaries blood moves to veins and back to the heart through the vena cava
• from vena cava it enters into right auricle which contracts and pumps blood into the right ventricle
• right ventricle pumps blood into the lungs through the pulmonary artery
• blood releases carbon IV oxide to lungs and picks oxygen then returns to left auricle
• left auricle pumps blood into left ventricle
• left ventricle then pumps blood into the aorta and into arteries, starting the process all over again
• both auricles contract simultaneously while both

iii) Explain how the mammalian heart is adapted to performing its functions

• the heart is made of muscles that contract and relax synchronously without requiring nervous stimulation
• nerve supply however, determine contraction strength and frequency
• the heart is divided into four chambers
• The right atrium is connected to the right auricle. It receives blood from the whole body.
• The blood is pumped from the left atrium to the right ventricle
• To avoid flow back into the right atrium, a valve is present between the two chambers the tricuspid valve
• The right ventricle pumps blood to the lungs
• This is facilitated by the presence of pulmonary artery
• A valve is also present to avoid blood flowing back from the pulmonary artery to the right ventricle
• Blood from the lungs enters the heart through the pulmonary vein into the left atrium.
• When the left atrium contracts, blood flows into the left ventricle
• Blood will not flow back into the left atrium because of the presence of bicuspid valve(mitral)
• The left ventricle is connected with the aorta and when it contracts, blood flows into the aorta for distribution into the whole body
• The heart muscle surrounding the left ventricle is thicker than that surrounding the right ventricle to be able to generate enough pressure to push blood to the whole body
• A pace-maker is present in the heart muscle to initiate and synchronise contractions.
• For the heart muscle to be well nourished and be provided with enough oxygen and carbon IV oxide removal, it is supplied with blood by the coronary arteries and drained by the coronary veins

iv) Explain why blood leaving the lungs may not be fully oxygenated

• under ventilation of the lungs
• blockage of alveoli (air sacs)
• high cardiac frequency i.e. high rate of pumping of blood in the heart

e) Describe the structure and functions of the blood vessels

i. Arteries

• carry away blood from the heart
• carry oxygenated blood except pulmonary artery which takes blood from the heart to lungs for oxygen
• have thick, muscular walls
• are elastic
• have narrow lumen
• all these adaptations are required to withstand high pressure caused by heartbeat

ii. Capillaries

• link arterioles and venules to arteries and veins
• small in diameter to increase pressure resistance for materials to filter out
• thin walled as they consist of a single layer of cells to allow diffusion of substances e.g leucocytes to tissues
• thin walled to allow presence of intercellular spaces
• large number i.e. numerous to provide a large surface area for exchange of materials
• have sphincter muscles at the junction of the arterioles and capillaries to control movement of blood into them
• lie close to the body for easy exchange of materials

iii. Veins

• carry blood back to the heart
• all carry deoxygenated blood except pulmonary vein that carries blood from the heart to lungs
• have thinner Walls than arteries
• have valves to prevent back flow of blood
• have wide lumen

3. i) State the ways in which the composition of blood in the pulmonary arterioles differs from that in the pulmonary venules

pulmonary arterioles

• deoxygenated
• high carbon iv oxide
• low oxygen
• more nutrients

pulmonary venules

• oxygenated
• low carbon iv oxide
• high oxygen
• less nutrients

ii) Give the reasons why pressure of blood is greater in the arterioles than I the veins of mammals

• blood is pumped to the arteries by the heart at high pressure
• blood pressure in veins is reduced by capillary resistance
• arteries have narrow lumen which maintains high pressure/veins have wide lumen which reduces pressure
• arteries have more/thicker muscular walls which generate pressure/veins have less/thinner muscular walls which reduce pressure

iii) Name the common heart diseases in humans

• thrombosis
• antheroma
• arteriosclerosis
• varicose veins
• cerebral vascular thrombosis

3. i) State the functions of mammalian blood

• transport of substances
• defense against diseases
• clotting
• temperature regulation

ii) Describe how mammalian blood components carry out their functions Plasma

• transport dissolved food substances like glucose, amino acids, fatty acids and glycerol from small intestines to liver and other body tissues
• transports hormones, enzymes from secretory glands to tissues when required
• transports carbon IV oxide to lungs and urea from tissues to the kidneys
• distributes heat
• bathes the tissues allowing for exchange of materials
• contains protein fibrinogen and pro-thrombin which take part in blood clotting

Red blood cells (Erythrocytes)

• transports oxygen from the lungs to body tissues in form of haemoglobin
• transport carbon IV oxide from body tissues to the lungs in form of bicarbonates

White blood cells (leucocytes)

• engulf foreign bodies
• produce antibodies for defense against disease
• produce antitoxins which neutralize bacterial toxins

Blood platelets (thrombocytes)

• produce an enzyme called thrombokinase/thromboplastin necessary for blood clotting
• prevents loss of blood, water and mineral salts

iii) State the Ways in which the red blood cells are adapted to their functions

• many per unit volume hence carry more oxygen and carbon IV oxide
• biconcave in shape to provide large surface area for absorption of oxygen and carbon IV oxide
• absence of nucleolus hence more haemoglobin to carry sufficient oxygen and carbon IV oxide
• alter shape to be able to pass through the narrow lumen of capillaries to deliver or supply oxygen and carry away carbon IV oxide
• have haemoglobin with high affinity for uptake of oxygen and carbon IV oxide

iv) State the structural differences between a red blood cell and a white blood cell.

Red blood cells

• has hemoglobin
• smaller size
• lacks nucleus

White blood cells

• not pigmented
• larger size
• nucleated

v) State the functional differences between a red blood cell and a White blood cell

Red blood cell

Transports oxygen and carbon IV oxide

White blood cell

Protects body against harmful pathogens

4. How does the heart increase blood flow to some parts of the body during exercise

• stronger contractions
• faster contractions/heartbeat

5. Explain how oxygen and carbon dioxide are transported in the blood

Oxygen

• oxygen concentration is higher in lungs(alveoli) that in blood
• oxygen in the alveoli dissolves in the film of moisture and diffuses through thin epithelial and capillary walls into plasma and red blood cells
• the oxygen combines with haemoglobin to form oxyhaemoglobin
• blood then becomes oxygenated
• blood from lungs then travels to all body tissues where the oxyhaemoglobin breaks down to form oxygen and haemoglobin
• haemoglobin is transported back to the lungs to collect more oxygen while the oxygen in capillaries diffuses into body cells for respiration
• respiration produces carbon dioxide

Carbon dioxide

• carbon dioxide produced during respiration diffuses out of cells into blood plasma and red blood cells due to concentration gradient
• carbon dioxide and water fonn carbonic acid carbamino compounds with haemoglobin
• in the presence of carboxyl anhydrase enzyme, hydrogen carbonate is carried in blood to the lungs
• in the lungs the hydrogen carbonate dissociates to liberate carbon dioxide which diffuses into alveolar cavity due to concentration gradient
• from alveolar space carbon IV oxide is expelled during expiration
• Most carbon dioxide is transported from tissues to lungs within the red blood cells and not in the blood plasma. Give the advantages of this mode of transport.
• PH of blood is not altered/homeostasis is maintained
• Within the red blood cell is an enzyme, carbonic anhyrase which helps in fast loading(combining) and offloading of carbon dioxide

6.  i) what is blood clotting?

process in which blood components clump together to prevent loss of blood from an injured/cut vessel

ii) Name a protein, vitamin, an enzyme and a mineral element involved in blood clotting

• Protein — fibrinogen/prothrombin
• Vitamin - k/quinine
• Enzyme — thrombokinase/thromboplatin/thrombin
• Mineral element — calcium

iii) describe the blood clotting process

• enzyme thromboplastin produced in the platelets of damaged tissues converts plasma
• protein prothrombin into thrombin in the presence of calcium ions
• thrombin converts another plasma protein fibrogen into fibrin in the presence of vitamin K
• fibrin is insoluble
• fibrin forms fibres which form a meshwork that forms a clot
• prothrombin thromboplastin thrombin
• calcium ion
• Fibrinogen thrombin fibrin clot
• vitamin K

iv) State the role of blood clotting on wounds

• prevents blood/body fluids from being lost
• conserves water and salts
• prevents entry of microorganisms/pathogens
• regulates body temperature
• enables wound to heal faster

v) Explain why blood flowing in blood vessels does not normally clot

Presence of anticoagulant in blood

7. i. list the major types of human blood groups

• O, with neither B nor A antigen
• AB, with both A and B antigens
• A, with type A antigen
• B, with type B antigen

ii. Explain the meaning of :

Universal donor

 
a person who can donate blood to any other blood group without agglutination/clumping

• this is usually blood group O
• however this person cannot receive blood from other blood groups except group O

Universal recipient

• can receive blood from all blood groups without agglutination
• this is usually blood group AB
• however, can only donate blood to group AB

iii) What is the difference between rhesus positive and Rhesus negative blood samples?

• rhesus positive blood has the Rhesus (Rh) antigen
• rhesus negative lacks the Rhesus antigen

vi) What is blood transfusion?

Introduction of blood from one person to another

v) Under what conditions would blood transfusion be necessary in people?

• during accidents
• during surgery in hospitals
• bleeding mothers when giving birth

vi) How can low blood volume be brought back to normal?

• transfusion
• taking fluids
• eating iron rich food/taking iron tablets

7. How may excessive bleeding result in death?

Anaemia/low blood volume/loss of iron/low red blood cells count/low hemoglobin leading to low oxygen, loss of nutrients and dehydration.

8. State the precautions that must be taken before blood transfusion

• blood must be disease free
• sterilized equipment must be used
• blood of the recipient and that of the donor must b compatible to both ABO and rhesus factor
• Fresh blood must be used.