Transport System, Blood

Explain the need for the transport system in multi-cellular organisms .

In small, single-celled organisms, substances like oxygen and nutrients can easily diffuse in and out of the cell. However, in multicellular organisms, diffusion alone is too slow to reach all the cells. This is why they need a transport system.

Name the substances which must be transported to a cell and explain why each substance is needed.

Substance to be transported

1. dissolved food - Transported to cells of the body - to be used for respiration, stored, Converted to other materials

2. oxygen - transported to body cells to be used for respiration

3. Carbon dioxide - transported to the lungs 🫁 to be excercted

4. nitrogenous waste - transported to the kidneys to be excreted.

limitations of simple Diffusion in multicellular organisms

Longer Distance to Travel → Cells deep inside the body do not get nutrients fast enough.

Higher Demand for Oxygen & Nutrients → Large organisms need more oxygen and food than diffusion alone can supply.

Waste Removal is Too Slow → Carbon dioxide and other wastes accumulate too quickly for diffusion to remove them fast enough.

Describe one adaptation in large organisms that helps overcome the limitations of a low surface area to volume ratio

One adaptation in large organisms to overcome low SA:V ratio:

The lungs in humans have millions of alveoli, which increase surface area for efficient gas exchange.

The circulatory system rapidly transports oxygen and nutrients to all cells via blood.

Gills in fish have thin, large-surface-area filaments to maximize oxygen absorption from water.

. How does the surface area to volume ratio affect the efficiency of diffusion in single-celled and multi-celled organisms

The SA:V ratio affects diffusion efficiency:

Small organisms (e.g., amoeba) have a high SA:V ratio, allowing rapid diffusion across their surface.

Large organisms (e.g., humans) have a low SA:V ratio, making diffusion alone too slow to transport gases and nutrients.

what are the three (3) main types of blood vessel and give a brief explanation of each

The main types of blood vessels are Artries veins and capillaries

Explaination :

Arteries:

There are three types of blood vessels arteries veins and capillaries. state the differnces between each

Arteries

1. Carry blood away from the heart,

2. Blood is at high pressure

3. Carrys oxygenated blood, expect the plumontary artey

4. No valves ( same for capillaries)

   Veins

   1. Carrys blood towards the heart

   2. Blood at low pressure

   3. Carry deoxygenated blood, expect the pulmonary vein

   4. Blood can flow in one direction because it (Has valves) valves is the structure that prevents blood from flowing backwards in the vines

   Capillaries

   1. No valves

   2. Blood flow very slowly ( Also occurs in veins )

   3. Blood at low pressure ( Also occurs in veins)

   4. Blood flows smoothly ( Also occurs in the Veins)

1. The walls of the heart is made up of special type of muscle called ?

2. Name the two substances required for the cardiac muscle to release energy. And state where they are suppplied from  

1. Cardiac Muscle.

2. These two substances are called : Oxygen and Glucose. It is supplied via the Coronary circulation

List the three main stages of the heartbeat and explain the importance of each.

Atrial systole – pushes blood from the atria into the ventricles.

Ventricular systole – pushes blood out of the heart, so that it can be pumped to the lungs through the pulmonary artery, and through the aorta to all parts of the body.

Diastole – allows blood from the body to collect in the atria, before it is forced into the ventricles by contraction of the muscles around the atria.

1. Which blood vessel carries oxygenated blood from the heart to the body?

2. Name the main vein that returns deoxygenated blood to the heart.

3. How does blood become deoxygenated in the body?

4. Which arteries supply oxygen to the heart itself?

5. What waste products does the blood pick up from the body cells?

6. Where does the blood go to get rid of urea?

7. Why is blood circulation important for transporting hormones?

8. It offloads carbon dioxide and picks up oxygen to become oxygenated.

1. Answer- The aorta.

2. The vena cava.

3. Blood gives oxygen to body cells for respiration and picks up carbon dioxide as waste.

4. The coronary arteries.

5. Carbon dioxide and urea

6. The kidneys.

7. It carries hormones from endocrine glands to different parts of the body where they are needed.

8. It offloads carbon dioxide and picks up oxygen to become oxygenated.

Describe the role of the heart in the circulatory system.

The heart pumps blood throughout the body, delivering oxygen and nutrients while removing waste like carbon dioxide. It has four chambers that ensure continuous blood circulation.

Why are the muscles of the left ventricle thicker than those of the right?

The left ventricle pumps blood to the entire body, requiring more force, while the right ventricle only pumps blood to the lungs, which is a shorter distance.

What happens if the coronary artery becomes blocked ?

A blockage prevents oxygen and nutrients from reaching the heart muscles, leading to chest pain (angina) or a heart attack.

Compare the structure of an artery with that of a vein.

Vein: Thin walls,contains valves to prevent backflow, carries blood toward the heart at low pressure.

Artery: Thick, muscular walls, carries blood away from the heart at high pressure.

How does the structure of an artery relate to its function?

Arteries have thick muscular walls to withstand high pressure from the heart’s pumping action it is bulit for endurance

The blood is composed of three types of cells.

1. Red Blood cells

2. white blood cells

3. platelets

Explain the structure of each componets of blood Red blood cells

1. Red blood cells - They have no nucleus,therefore only live 3 to 4 months, contains red pigment haemoglobin and Bi- con-cave disc shape gives a large surface area for diffusion

   Function of the red blood cell is : transport Oxygen and some carbon dioxide

Explain the structure of each componets of blood Platelets or thrombocytes and state it functions

The structure :

•cell fragments

• no nucleus

• formed in bone marrow of lone bones

The fuction of the platelets or thro-mo-bo-cytes are : it helps blood to clot at cute or wound

When the skin is cut and a blood vessel breaks, a clot forms to stop blood loss and block harmful organisms. The clotting process involves fibrin, a protein that traps blood cells to seal the gap. Severe blood loss, called hemorrhage, can be life-threatening, but a blood transfusion can help by replacing lost blood.

Questions:

1. Why is it important for a blood clot to form when a vessel is cut?

2. What role does fibrin play in blood clotting?I

3. What is a hemorrhage, and why is it dangerous?

4. How does a blood transfusion help during severe blood loss?

1. A blood clot is essential when a blood vessel is cut because it stops further blood loss and acts as barrier to prevent harmful organisms from entering the body.

2. Fibrin forms a network of fibers that trap blood cells, creating a stable clot that seals the cut and aids in healing. or

Fibrin forms a network of fibers that trap blood cells, creating a clot to seal the cut and promote healing

3. A hemorrhage is significant blood loss from a broken vessel, which can be life-threatening because it reduces the blood volume needed to transport oxygen and nutrients.

4. A blood transfusion replaces the lost blood, maintaining blood volume and oxygen transport, which can save a person's life.

1. What is a blood transfusion, and why is compatibility important?

2. Describe how blood groups are classified and name the four blood groups.

3. Explain the role of antigens and antibodies in blood transfusion.

4. What could happen if incompatible blood types are mixed during a transfusion?

5. Why is it important to know both the antigen on the donor’s red blood cells and the antibody in the recipient’s plasma before a transfusion?

1. A blood transfusion is giving blood from one person to another. Compatibility is important to prevent the red blood cells from sticking togeother leading to a fetal reaction

2. Blood groups (A, B, AB, O) are based on proteins (antigens) on red blood cells. For example, group A has antigen A.

3. Antigens are proteins on red blood cells; antibodies are in plasma. They must not match, or clumping will occur.

4. If incompatible blood types mix, red blood cells clump, blocking blood vessels and causing harm.

5. Knowing the donor’s antigen and recipient’s antibody prevents harmful clumping during transfusion.

Explain how any two features of red blood cells ensures that its suitable for major function in the human body

1. No nucleus - Allows them to carry more haemoglobin due to more speace

2. bioconcave disc - this makes it easier to travel through the blood vessels

3. Alot of of haemoglobin- Allows them to pick up and transport oxygen easily and effectively

Explain how any two features of white blood cells ensures that its suitable for major function in the human body

1. Can engulf and digest pathogens (phagocytosis).

2. Produce antibodies to fight infections.

3. Can move out of blood vessels to reach infection sites.

Explain how any two features of platelets cells ensures that its suitable for major function in the human body

1.Release clotting factors to stop bleeding.

2. Form a plug at the site of a wound.

3. Help in the formation of fibrin to stabilize the clot.

What is hypertension?

Hypertension is prolonged high blood pressure.

What factors in a person’s life may increase the chances of suffering from hypertension

Factors that contribute to the chances of suffering from hypertension are:

• a genetic predisposition (having a relative who suffers from the disease);

• smoking;

• obesity;

• diet that contains many fatty foods;

• no exercise;

• old age

How can a person prevent having hypertension ?

A healthy lifestyle, that includes regular exercise, no smoking, low intake of fat, salt and alcohol, can prevent the development of hypertension.

what is an anitigen ?

Anything that is foreign or different and causes antibody formation is called an antigen.

Questions:

1. What role do memory lymphocytes play in natural immunity?

2. Why does natural immunity prevent symptoms from developing during a second infection?

3. Explain how the production of antibodies contributes to natural immunity.

1. Memory lymphocytes recognize specific antigens if they invade a second time and rapidly produce large amounts of the specific antibody.

2. During a second infection, memory lymphocytes quickly produce antibodies, destroying the antigens before symptoms can develop.

3. Antibodies neutralize or destroy antigens or the toxins they produce, clearing the infection and preventing symptoms during future exposures.

Why does the first exposure to a pathogen often result in illness, while subsequent exposures do not?

During the first infection, antibodies are produced slowly, giving pathogens enough time to cause disease because only the specific antibodies for that antigen are made. In a second infection, antibodies are produced rapidly and in large quantities, destroying the pathogens before symptoms appear, making the person immune to the disease.

There are two types of natural immuntiy :

1. Actively Acquired Immunity: The body produces antibodies after being exposed to a pathogen, providing long-term protection.

2. Passively Acquired Immunity: Antibodies are received from another source, like from mother to baby, offering short-term protection.

1. Why is it important for vaccines used in active immunity to contain treated antigens?

2. How does passive immunity differ from active immunity in terms of antibody production?

3. In what situation would a person receive passive immunity instead of active immunity?

Vaccines contain treated antigens that help the body build immunity without causing the disease.

Active immunity involves the body making antibodies, while passive immunity involves receiving antibodies

Passive immunity is used when someone is infected and lacks immunity.

Explain what is meant by a vaccine

A vaccine is a substance injected into the body. It contains antigens which cause the immune response, or antibodies which protect the body

EASY ANSWER

A vaccine is an injection that helps the body fight diseases by triggering an immune response.

Explain the meaning of the term ‘immunisation’ and give one advantage of immunisation

Immunisation is the process of giving vaccines to protect against various diseases. It also refers to the act of introducing the vaccine into a person’s body.

One advantage of immunisation is that it helps prevent diseases.

One disadvantage of immunisation is that some people may experience mild side effects, like fever or soreness, after receiving a vaccine. In rare cases, more severe reactions can occur.

We are surrounded by pathogens. How is the body protected from infection?

The body has three lines of defense against infection:

1. The skin acts as a physical barrier, and blood clotting at openings helps keep pathogens out.

2. If pathogens enter through a wound, phagocytes move to the area and destroy them.

3. Antibodies are produced to find and neutralize or destroy invading bacteria or other antigens.